cholecystokinin and Hyperglycemia

Normal digestive physiology is a highly orchestrated process, integrating the mechanical breakdown of food, the secretion of digestive juices, the control of motility, and the efficient absorption of nutrients. As enteral and parenteral feeding techniques bypass many of these control mechanisms, nutritional utilization can be expected to be disturbed. This review examines recent publications that have investigated this question in clinical practice.. Studies in healthy volunteers have shown that all forms of oral and enteral tube feeds commonly used, including proximal jejunal elemental diets, stimulate pancreatic secretion. Avoidance of the cephalic phase with duodenal feeding does not reduce the secretory response. 'Pancreatic rest' can, however, be achieved if feeding is delivered 40-60 cm past the ligament of Treitz by activating the ileal brake, or if it is given intravenously by avoiding intestinal cholecystokinin stimulation and the cholinergic reflex. These forms of feeding, however, can cause complications as they will result in malabsorption unless elemental formulae are used, and hyperglycemia as the metabolic utilization of intravenous nutrients is impaired.. An understanding of normal pancreatic physiology and how interventional feeding techniques affect it will help prevent complications and improve outcome in hospitalized patients.

Topics: Cholecystokinin; Enteral Nutrition; Hospitalization; Humans; Hyperglycemia; Malabsorption Syndromes; Pancreas; Parenteral Nutrition

Topics: Age Factors; Anemia, Pernicious; Antigen-Antibody Reactions; Antigens, Neoplasm; Cholecystokinin; Cross Reactions; Digestive System Physiological Phenomena; Duodenal Ulcer; Gastric Mucosa; Gastrins; Gastrointestinal Diseases; Gastrointestinal Hormones; Gastrointestinal Neoplasms; Glucagon; Hepatitis B Antigens; Hormones; Humans; Hyperglycemia; Insulin; Methods; Radioimmunoassay; Secretin; Zollinger-Ellison Syndrome

Eggs attenuate postprandial hyperglycaemia (PPH), which transiently impairs vascular endothelial function (VEF). We hypothesised that co-ingestion of a glucose challenge with egg-based meals would protect against glucose-induced impairments in VEF by attenuating PPH and oxidative stress. A randomised, cross-over study was conducted in prediabetic men (n 20) who ingested isoenegertic meals (1674 kJ (400 kcal)) containing 100 g glucose (GLU), or 75 g glucose with 1·5 whole eggs (EGG), seven egg whites (WHITE) or two egg yolks (YOLK). At 30 min intervals for 3 h, brachial artery flow-mediated dilation (FMD), plasma glucose, insulin, cholecystokinin (CCK), lipids (total, LDL- and HDL-cholesterol; TAG), F2-isoprostanes normalised to arachidonic acid (F2-IsoPs/AA), and methylglyoxal were assessed. In GLU, FMD decreased at 30-60 min and returned to baseline levels by 90 min. GLU-mediated decreases in FMD were attenuated at 30-60 min in EGG and WHITE. Compared with GLU, FMDAUC was higher in EGG and WHITE only. Relative to baseline, glucose increased at 30-120 min in GLU and YOLK but only at 30-90 min in EGG and WHITE. GlucoseAUC and insulinAUC were also lower in EGG and WHITE only. However, CCKAUC was higher in EGG and WHITE compared with GLU. Compared with GLU, F2-IsoPs/AAAUC was lower in EGG and WHITE but unaffected by YOLK. Postprandial lipids and methylglyoxal did not differ between treatments. Thus, replacing a portion of a glucose challenge with whole eggs or egg whites, but not yolks, limits postprandial impairments in VEF by attenuating increases in glycaemia and lipid peroxidation.

Topics: Adult; Arachidonic Acid; Blood Glucose; Brachial Artery; Cholecystokinin; Cross-Over Studies; Diet; Dietary Carbohydrates; Egg White; Eggs; Endothelium, Vascular; Energy Intake; Glucose; Glucose Tolerance Test; Humans; Hyperglycemia; Insulin; Lipid Peroxidation; Male; Middle Aged; Prediabetic State; Vasodilation

A randomized, double-blind, placebo-controlled, cross-over, dose-escalating, single-center study was conducted to evaluate the safety, tolerability, and pharmacokinetic (PK) profile of multiple once-daily (qd) subcutaneous (sc) doses of pasireotide in healthy male subjects. Subjects received pasireotide 50, 200, or 600 μg sc qd for 14 days and placebo in separate sequences. Thirty-three subjects were randomized. The most frequently reported drug-related adverse events were injection-site reactions (n = 18), diarrhea (n = 14) and nausea (n = 10), which were mostly mild or moderate in intensity. Pasireotide 600 μg sc was associated with pre- and post-prandial elevations in glucose levels relative to placebo; however, this effect was less pronounced on day 14 compared with day 1. PK steady state appeared to be achieved after 3 days of dosing and PK exposures had a moderate accumulation of 20-40 % across doses. Pasireotide demonstrated fast absorption (T(max,ss): 0.25-0.5 h), low clearance (CL/F(ss): 8.10-9.03 L/h), long effective half-life (T(½,eff): ~12 h, on average between 9.7 and 13.1 h for 50, 200, and 600 μg sc qd), and large volume of distribution (V(z)/F(ss): 251-1,091 L) at steady state. Dose proportionality was confirmed for C(max,ss); other PK parameters (C(max), AUC(0-24 h) and AUC(tau)) were approximately dose proportional. Growth hormone inhibition was observed with pasireotide 200 and 600 μg sc qd. Gallbladder volume increased post-prandially with pasireotide 200 and 600 μg sc qd, which appeared to correlate with reduced levels of cholecystokinin at these doses. Pasireotide was generally well tolerated up to the tested dose of 600 μg qd, with a linear and time-independent PK profile after sc qd dosing in healthy subjects.

Topics: Adult; Antineoplastic Agents, Hormonal; Cholecystokinin; Cross-Over Studies; Diarrhea; Dose-Response Relationship, Drug; Double-Blind Method; Gallbladder; Half-Life; Human Growth Hormone; Humans; Hyperglycemia; Injections, Subcutaneous; Male; Metabolic Clearance Rate; Nausea; Organ Size; Somatostatin; Tachyphylaxis; Young Adult

Pancreatico-biliary secretion is reduced during acute hyperglycemia. We investigated whether alterations in pancreatico-biliary flow or volume output are responsible for the observed reduction in duodenal output of pancreatic enzymes and bilirubin during hyperglycemia. Eight healthy subjects were studied on two occasions during normoglycemia and hyperglycemia (15 mmol/l). Pancreatico-biliary output was measured by aspiration using a recovery marker under basal conditions (60 min), during secretin infusion (0.1 CU/kg.h) for 60 min and during secretin + CCK (0.5 IDU/kg.h) infusion for 60 min. Secretin was infused to stimulate pancreatico-biliary flow and volume output. Secretin significantly (P<0.005-P<0.05) increased volume and bicarbonate output and CCK significantly (P<0.01) increased the output of bilirubin, pancreatic enzymes, bicarbonate and volume, both during normoglycemia and hyperglycemia. During hyperglycemia basal, secretin stimulated and secretin + CCK stimulated total pancreatico-biliary output were significantly (P<0.005-P<0.05) reduced compared to normoglycemia. The incremental outputs, however, were not significantly different between hyper- and normoglycemia. Pancreatic volume output was significantly (P<0.05) reduced during hyperglycemia compared to normoglycemia under basal conditions (31+/-16 m/h versus 132+/-33 m/h) during secretin infusion (130+/-17 ml/h versus 200+/-34 m/h) and during secretin + CCK infusion (370+/-39 ml/h versus 573+/-82 ml/h). Plasma PP levels were significantly (P<0.05) reduced during hyperglycemia. It is concluded that 1) hyperglycemia significantly reduces basal pancreatico-biliary output 2) the incremental pancreaticobiliary output in response to secretin or secretin + CCK infusion is not significantly affected during hyperglycemia, 3) a reduction in volume output contributes to the inhibitory effect of hyperglycemia on pancreatico-biliary secretion, 4) hyperglycemia reduces PP secretion suggesting vagal-cholinergic inhibition of pancreatico-biliary secretion and volume during hyperglycemia.

Topics: Adult; Amylases; Bicarbonates; Biliary Tract; Bilirubin; Blood Glucose; Cholecystokinin; Duodenum; Fasting; Female; Glucose Clamp Technique; Humans; Hyperglycemia; Male; Pancreas; Pancreatic Polypeptide; Secretin; Time Factors; Trypsin

Acute hyperglycemia inhibits gallbladder contraction. In non-diabetic subjects this inhibitory effect may result from endogenous hyperinsulinemia. Therefore we investigated the effects of acute hyperglycemia and euglycemic hyperinsulinemia on basal and cholecystokinin-stimulated gallbladder motility.. Gallbladder volume (ultrasonography) and duodenal bilirubin output were studied simultaneously in nine healthy volunteers (age 20-52 years) on 3 separate occasions in random order during: (a) saline infusion (control), (b) hyperglycemic hyperinsulinemic clamping (HG; plasma glucose at 15 mmol/l), and (c) euglycemic hyperinsulinemic clamping (HI; plasma insulin at 150 mU/l, glucose at 4-5 mmol/l). After a 2-h basal clamp period, cholecystokinin was infused intravenously for 60 min at 0.25 IDU x kg(-1) x h(-1), followed by another 60 min at 0.5 IDU x kg(-1) x h(-1).. HI and HG significantly (p<0.05) reduced basal duodenal bilirubin output compared to control, while basal gallbladder volume did not change. At the low dose cholecystokinin, gallbladder emptying during HG (25+/-3%) and HI (39+/-4%) was significantly (p<0.01) reduced compared to control (61+/-4%). The inhibitory effect of HG was significantly (p<0.05) stronger compared to HI. Duodenal bilirubin output during the low dose cholecystokinin was significantly (p<0.05) reduced by HG, but not by HI. No inhibitory effect of HG and HI on gallbladder emptying and duodenal bilirubin output was observed with the high dose of cholecystokinin.. In healthy subjects acute hyperglycemia and euglycemic hyperinsulinemia reduce basal duodenal bilirubin output and inhibit gallbladder emptying stimulated by low dose cholecystokinin. These results suggest that insulin is involved in the inhibitory effect of hyperglycemia on basal and cholecystokinin-stimulated gallbladder motility.

Topics: Adult; Analysis of Variance; Basal Metabolism; Blood Glucose; Cholecystokinin; Female; Gallbladder; Gallbladder Emptying; Glucose Clamp Technique; Humans; Hyperglycemia; Hyperinsulinism; Hypoglycemic Agents; Insulin; Male; Middle Aged; Muscle Contraction; Reference Values; Stimulation, Chemical

This study was undertaken to investigate the effect of acute hyperglycemia on basal and bombesin-stimulated pancreaticobiliary secretion. Seven healthy subjects participated in two experiments performed in random order during normoglycemia and hyperglycemic clamping at 15 mM. Duodenal outputs of bilirubin, trypsin, amylase, and bicarbonate were measured by aspiration with a recovery marker under basal conditions for 60 min and during continuous infusion of bombesin (1 ng/kg x min) for 60 min. Plasma cholecystokinin (CCK) and pancreatic polypeptide (PP) levels were determined at regular intervals. Compared to normoglycemia, during hyperglycemia basal outputs of bilirubin (17 +/- 3 vs. 0.9 +/- 0.4 micromol/60 min), trypsin (24 +/- 4 vs. 4 +/- 1 U/60 min), amylase (12 +/- 1 vs. 3 +/- 1 kU/60 min), and bicarbonate (2.9 +/- 0.5 vs. 1.2 +/- 0.2 mmol/60 min) were significantly p < 0.05) reduced. Bombesin significantly (p < 0.05) increased pancreaticobiliary output during both normo- and hyperglycemia. During hyperglycemia bombesin-stimulated 60-min outputs of bilirubin, trypsin, amylase, and bicarbonate were not significantly different compared to those during normoglycemia. Basal and bombesin-stimulated plasma PP concentrations were significantly (p < 0.05) reduced during hyperglycemia, but plasma CCK levels were not significantly different. It is concluded that acute hyperglycemia reduces basal but does not affect bombesin-induced pancreaticobiliary secretion.

Topics: Acute Disease; Adult; Amylases; Bicarbonates; Biliary Tract; Bilirubin; Blood Glucose; Bombesin; Cholecystokinin; Humans; Hyperglycemia; Pancreas; Pancreatic Polypeptide; Trypsin

This study was undertaken to investigate the effect of acute hyperglycemia on pancreatico-biliary secretion in healthy subjects. Duodenal outputs of bilirubin, amylase, trypsin and bicarbonate were measured by aspiration using a recovery marker under basal condition for 75 min and during continuous infusion of CCK (0.5 IDU/kg.h for 60 min). Seven healthy subjects participated in two experiments performed in random order during normoglycemia and during acute hyperglycemic clamping at 15 mmol/l. At regular intervals plasma PP levels were determined as an indirect measure of vagal-cholinergic tone. Basal pancreatico-biliary secretion was significantly (p<0.05) reduced during acute hyperglycemia. CCK significantly (p<0.05) increased bilirubin, amylase and trypsin output both during normo- and hyperglycemia. During the initial 30 min of CCK infusion the bilirubin, amylase and trypsin outputs were significantly (p<0.05) inhibited in the hyperglycemic experiment compared to normoglycemia. In the following 30 min of CCK infusion the bilirubin, amylase and trypsin output were not different between hyper- and normoglycemia. Basal and CCK-stimulated plasma PP concentrations were significantly (p<0.05) reduced during hyperglycemia. In summary: 1) basal pancreatico-biliary secretion is significantly reduced during acute hyperglycemia 2) during hyperglycemia CCK-stimulated pancreatico-biliary secretion is also significantly reduced with the pattern of a delayed response 3) hyperglycemia inhibits basal and CCK-stimulated PP secretion suggesting impaired vagal-cholinergic activity during hyperglycemia.

Topics: Acute Disease; Adult; Amylases; Biliary Tract; Bilirubin; Blood Glucose; Cholecystokinin; Humans; Hyperglycemia; Pancreas; Pancreatic Polypeptide; Trypsin

1. We have investigated the effect of acute hyperglycaemia on pancreatico-biliary secretion in healthy subjects. Duodenal outputs of trypsin, lipase, amylase, bicarbonate and bilirubin were measured for 90 min under basal conditions and for 90 min in response to intrajejunal fat administration (1 g/h) on 2 separate days: during normoglycaemia (blood glucose 5 mmol/l) and during acute hyperglycaemia aimed at 15 mmol/l. Plasma cholecystokinin levels, as the major hormonal stimulus of pancreatic and biliary secretion, and plasma pancreatic polypeptide levels, as an indirect measure of vagal-cholinergic tone, were determined at regular intervals. 2. In the basal period pancreatico-biliary secretion was significantly (P < 0.05) reduced during hyperglycaemia compared with normoglycaemia. During normoglycaemia and hyperglycaemia intrajejunal fat significantly (P < 0.05) stimulated pancreaticobiliary secretion. However, during hyperglycaemia, fat-stimulated 90 min pancreatico-biliary secretion was significantly (P < 0.05) reduced compared with normoglycaemia: trypsin (23 +/- 7 units versus 66 +/- 20 units), lipase (36 +/- 8 k-units versus 74 +/- 18 k-units), amylase (8 +/- 2 k-units versus 18 +/- 5 k-units) and bilirubin (32 +/- 8 mumol versus 71 +/- 14 mumol). Plasma cholecystokinin levels increased significantly (P < 0.05) during fat administration and were not different between the two experiments. Plasma pancreatic polypeptide levels were significantly (P < 0.05) reduced during hyperglycaemia both in the basal period and during intrajejunal fat administration. 3. It is concluded that basal and fat-stimulated pancreatico-biliary secretion are significantly reduced during acute hyperglycaemia. Acute hyperglycaemia does not affect intrajejunal fat-stimulated cholecystokinin secretion. Acute hyperglycaemia inhibits basal and stimulated pancreatic polypeptide secretion suggesting vagal-cholinergic inhibition of pancreatico-biliary secretion during hyperglycaemia.

Topics: Acute Disease; Adult; Amylases; Bicarbonates; Bile; Bilirubin; Cholecystokinin; Dietary Fats; Female; Humans; Hyperglycemia; Lipase; Male; Pancreas; Pancreatic Polypeptide; Trypsin

To assess the influence of enteric factors on insulin action, seven lean healthy subjects were studied under conditions of hyperinsulinemic euglycemic glucose clamp, double isotope administration, and enteral vs. parenteral glucose infusion. In random order, glucose and mannitol radiolabeled with [2-3H]glucose were infused intraduodenally for 4 h while the systemic rate of glucose turnover was assessed by [6-14C]glucose. During the final hour of the study, plasma glucose, insulin, C-peptide, glucagon, cholecystokinin, and neurotensin were similar under both experimental conditions. Despite an increase in gastric inhibitory polypeptide concentration during combined enteral and iv glucose infusion to levels that mimicked meal ingestion, total glucose infusion rate, insulin-induced stimulation of glucose uptake, and insulin-induced suppression of hepatic glucose release were comparable to those observed during iv glucose administration. These data indicate that under conditions of modest hyperinsulinemia and euglycemia, gastric inhibitory polypeptide did not influence hepatic or extrahepatic insulin action.

Topics: Adult; Blood Glucose; C-Peptide; Cholecystokinin; Duodenum; Female; Gastric Inhibitory Polypeptide; Glucose; Humans; Hyperglycemia; Hyperinsulinism; Infusions, Parenteral; Insulin; Liver; Male; Mannitol; Spleen

Immunoglobulin-like Domain-Containing Receptor 1 (ILDR1) is expressed on nutrient sensing cholecystokinin-positive enteroendocrine cells of the gastrointestinal tract and it has the unique ability to induce fat-mediated CCK secretion. However, the role of ILDR1 in CCK-mediated regulation of satiety is unknown. In this study, we examined the effects of ILDR1 on food intake and metabolic activity using mice with genetically-deleted Ildr1.. The expression of ILDR1 in murine tissues and the measurement of adipocyte cell size were evaluated by light and fluorescence confocal microscopy. The effects of Ildr1 deletion on mouse metabolism were quantitated using CLAMS chambers and by targeted metabolomics assays of multiple tissues. Hormone levels were measured by ELISA. The effects of Ildr1 gene deletion on glucose and insulin levels were determined using in vivo oral glucose tolerance, meal tolerance, and insulin tolerance tests, as well as ex vivo islet perifusion.. ILDR1 is expressed in a wide range of tissues. Analysis of metabolic data revealed that although Ildr1-/- mice consumed more food than wild-type littermates, they gained less weight on a high fat diet and exhibited increased metabolic activity. Adipocytes in Ildr1-/- mice were significantly smaller than in wild-type mice fed either low or high fat diets. ILDR1 was expressed in both alpha and beta cells of pancreatic islets. Based on oral glucose and mixed meal tolerance tests, Ildr1-/- mice were more effective at lowering post-prandial glucose levels, had improved insulin sensitivity, and glucose-regulated insulin secretion was enhanced in mice lacking ILDR1.. Ildr1 loss significantly modified metabolic activity in these mutant mice. While Ildr1 gene deletion increased high fat food intake, it reduced weight gain and improved glucose tolerance. These findings indicate that ILDR1 modulates metabolic responses to feeding in mice.

Topics: Animals; Cholecystokinin; Diet, High-Fat; Gene Deletion; Glucose; Hyperglycemia; Insulin; Insulin Resistance; Mice; Mice, Inbred C57BL; Obesity; Receptors, Cell Surface

Cholecystokinin (CCK) is a peptide hormone produced in the gut and brain with beneficial effects on digestion, satiety, and insulin secretion. CCK is also expressed in pancreatic β-cells, but only in models of obesity and insulin resistance. Whole body deletion of CCK in obese mice leads to reduced β-cell mass expansion and increased apoptosis. We hypothesized that islet-derived CCK is important in protection from β-cell apoptosis. To determine the specific role of β-cell-derived CCK in β-cell mass dynamics, we generated a transgenic mouse that expresses CCK in the β-cell in the lean state (MIP-CCK). Although this transgene contains the human growth hormone minigene, we saw no expression of human growth hormone protein in transgenic islets. We examined the ability of MIP-CCK mice to maintain β-cell mass when subjected to apoptotic stress, with advanced age, and after streptozotocin treatment. Aged MIP-CCK mice have increased β-cell area. MIP-CCK mice are resistant to streptozotocin-induced diabetes and exhibit reduced β-cell apoptosis. Directed CCK overexpression in cultured β-cells also protects from cytokine-induced apoptosis. We have identified an important new paracrine/autocrine effect of CCK in protection of β-cells from apoptotic stress. Understanding the role of β-cell CCK adds to the emerging knowledge of classic gut peptides in intraislet signaling. CCK receptor agonists are being investigated as therapeutics for obesity and diabetes. While these agonists clearly have beneficial effects on body weight and insulin sensitivity in peripheral tissues, they may also directly protect β-cells from apoptosis.

Topics: Aging; Animals; Apoptosis; Cell Line; Cholecystokinin; Cytokines; Diabetes Mellitus, Type 2; Down-Regulation; Hyperglycemia; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Mice, Transgenic; Promoter Regions, Genetic; Rats; Recombinant Proteins; Streptozocin; Stress, Physiological; Tissue Culture Techniques

The present study examines the differences in gastrointestinal hormone production at 3 different reconstruction types after total gastrectomy.. Total gastrectomy causes significant weight loss, mainly due to a reduced caloric intake probably because of a lack of initiative to eat or early satiety during meals. Behind this phenomenon a disturbed gastrointestinal hormone production can be presumed.. Patients participating in a randomized study were recruited for the clinical experiment. Seven patients with simple Roux-en-Y reconstruction, 11 with aboral pouch (AP) construction, and 10 with aboral pouch with preserved duodenal passage (APwPDP) reconstruction, as well as 6 healthy volunteers were examined. Blood samples were taken 5 minutes before and 15, 30, and 60 minutes after ingestion of a liquid test meal. Plasma concentrations for insulin, cholecystokinin, and somatostatin were determined by radioimmunoassay analysis.. Postprandial hyperglycemia was observed in patients after total gastrectomy most prominently in groups with duodenal exclusion (Roux-en-Y and AP) compared with healthy controls. Postprandial insulin curves reached significantly higher levels in all operated groups compared with controls, however, with no difference according to reconstruction type. Significantly higher cholecystokinin levels and higher integrated production of cholecystokinin were observed in Roux-en-Y and AP groups compared with APwPDP and control. Postprandial somatostatin levels were significantly different between the 4 groups, and highest levels and integrated secretions were reached in AP group, lowest in APwPDP and normal groups.. A disturbed glucose homeostasis was observed in gastrectomized patients most prominently in the Roux-en-Y group. Also, cholecystokinin and somatostatin response differed significantly in favor of duodenal passage preservation after total gastrectomy. Cholecystokinin levels close to physiologic found at APwPDP reconstruction may contribute to a physiologic satiation in reconstructions with preserved duodenal passage after total gastrectomy.

Topics: Anastomosis, Roux-en-Y; Anastomosis, Surgical; Blood Glucose; Cholecystokinin; Female; Gastrectomy; Gastrointestinal Hormones; Homeostasis; Humans; Hyperglycemia; Insulin; Male; Middle Aged; Plastic Surgery Procedures; Postoperative Complications; Postprandial Period; Satiety Response; Somatostatin

Topics: Animals; Cell Division; Cholecystokinin; Colon; Gastric Inhibitory Polypeptide; Humans; Hyperglycemia; Ileum; Insulin; Insulin Secretion; Islets of Langerhans; Pancreas; Rats; Sincalide

Pancreaticobiliary secretion is reduced during acute hyperglycemia. In nondiabetics, this inhibitory effect also may result from hyperinsulinemia. Therefore we investigated the effects of acute hyperglycemia and euglycemic hyperinsulinemia on basal and cholecystokinin (CCK)-stimulated pancreaticobiliary secretion. Nine healthy volunteers (age, 22-52 years) were studied on three occasions in random order during (a) intravenous saline (control), (b) hyperglycemic hyperinsulinemic clamping (HG; plasma glucose at 15 mM), and (c) euglycemic hyperinsulinemic clamping (HI; plasma insulin at 150 mU/L, glucose at 4-5 mM). Duodenal outputs of bilirubin, amylase, trypsin, and bicarbonate were measured under basal conditions and during CCK infusion (0.25 and 0.5 IDU/kg/h). Basal pancreaticobiliary secretion was significantly (p < 0.05) reduced during both HG and HI. During low-dose CCK stimulation, HG significantly (p < 0.05) reduced bilirubin and trypsin output compared with control. In contrast, HI did not significantly reduce pancreatic enzyme and bilirubin output during low-dose CCK infusion. During high-dose CCK infusion, neither HI nor HG influenced pancreatic enzyme and bilirubin output. Pancreatic bicarbonate output was not influenced by CCK and remained significantly (p < 0.05) reduced during HI and HG compared with control. It is concluded that during both acute hyperglycemia and euglycemic hyperinsulinemia, basal pancreaticobiliary secretion is significantly reduced. CCK-stimulated pancreatic enzyme and bilirubin output is significantly reduced only during hyperglycemia. The inhibitory effect of hyperglycemia on pancreaticobiliary secretion in healthy volunteers may occur independent of insulin.

Topics: Adult; Bicarbonates; Bilirubin; Blood Glucose; Cholecystokinin; Duodenum; Female; Glucose; Glucose Clamp Technique; Humans; Hyperglycemia; Hyperinsulinism; Insulin; Male; Middle Aged; Pancreas; Trypsin

In the present study the effects of intraduodenal (i.d.) fat (endogenous CCK) and of CCK infusion on satiety were studied during normo-and hyperglycemic conditions. Eight healthy subjects participated in two protocols consisting of two experiments each. First protocol: (a) normoglycemia (control) with i.d. emulsified fat (i.d. fat) infusion, (b) acute hyperglycemia (HG) with plasma glucose levels stabilized at 15 mmol/L and i.d. fat infusion. In the second protocol the effect of exogenous cholecystokinin (CCK) on satiety was studied during normo- and hyperglycemia. Intraduodenal fat (Intralipid 10%) was infused at a dose of 1 g/h via a nasoduodenal tube in the first protocol, whereas in the second protocol CCK-33 was infused intravenously at a dose of 0.5 IDU/kg x h. Satiety was scored using visual analog scales (VAS). Plasma CCK levels were determined at regular intervals. During infusion of i.d. fat and i.v. CCK the VAS scores of wish to eat, hunger, and prospective feeding decreased significantly (p<0.05) in the normoglycemic experiments. During hyperglycemia satiety did not significantly change in the basal period; however, the scores of wish to eat, hunger, and prospective feeding increased significantly (p<0.05) when i.d. fat or i.v. CCK was administered. Plasma CCK levels in the basal and the stimulated period were not significantly different between normo- and hyperglycemia. In summary, the present study shows that in healthy humans volunteers 1) during normoglycemic conditions satiety can be induced by very low dose of i.d. fat and by CCK infusion, 2) during hyperglycemia the effect of i.d. fat and CCK on satiety are reversed, resulting in increased appetite.

Topics: Adult; Appetite; Blood Glucose; Cholecystokinin; Duodenum; Fats; Glucose Clamp Technique; Humans; Hyperglycemia; Infusions, Intravenous; Insulin; Intubation, Gastrointestinal; Middle Aged; Satiety Response

Patients with early non-insulin-dependent diabetes mellitus (NIDDM) empty glucose solutions from their stomachs more rapidly than non-diabetic control subjects, and this exacerbates postprandial hyperglycaemia. To determine if accelerated gastric emptying occurred in a rat model of NIDDM and influenced postprandial hyperglycaemia, gastric emptying of glucose was measured, and the effect of slowing the gastric emptying rate on postprandial hyperglycaemia was observed. We tested eight male obese Zucker diabetic rats and eight age-matched lean Zucker controls at 10-13 weeks of age to measure gastric emptying of glucose (by gamma scintigraphy). Rats fasted overnight were gavaged with 30% glucose at 1 ml/100 g body weight. Separately, six Zucker diabetic rats and six lean controls were tested for sensitivity to the inhibitory effects of cholecystokinin and secretin on gastric emptying. The diabetic rats emptied glucose significantly faster than controls (t1/2 = 37.3 +/- 1.5 vs 58.8 +/- 2.3 min in controls), and aging exaggerated this differential. Camostat, a stimulant of cholecystokinin and secretin release, added to the glucose meal significantly slowed gastric emptying (t1/2 = 123 +/- 23 and 166 +/- 19 min, diabetic vs lean, respectively), and significantly reduced postprandial hyperglycaemia in diabetic rats. Compared to Zucker lean controls, Zucker diabetic rats were as sensitive (cholecystokinin) or more sensitive (secretin) to gastrointestinal hormones that inhibit gastric emptying. The results demonstrate accelerated gastric emptying in a rat model of NIDDM, consistant with similar observations in humans with early NIDDM. These results also support the proposal that interventions to slow gastric emptying improve glucose control in this disease.

Topics: Animals; Cholecystokinin; Diabetes Mellitus, Type 2; Esters; Gabexate; Gastric Emptying; Glucose; Guanidines; Hyperglycemia; Male; Postprandial Period; Rats; Rats, Zucker; Secretin; Trypsin Inhibitors

Patients with diabetes mellitus are at increased risk of developing gallstones. This has been attributed, among other factors, to alterations in gallbladder motility in the presence of autonomic neuropathy. Since high blood glucose concentrations impair gastric emptying in diabetic patients, we have investigated the effect of acute hyperglycaemia on gallbladder motility. Seven Type 1 (insulin-dependent) diabetic patients were studied twice during euglycaemia (blood glucose 5 mmol/l) and hyperglycaemia (blood glucose 15 mmol/l) using a clamp technique. In addition, seven healthy volunteers were studied during euglycaemia and hyperglycaemia. Gallbladder volumes, measured with ultrasonography, were studied before and during infusion of step-wise increasing doses of cholecystokinin-33, 0.25, 0.5 and 1.0 Ivy Dog Unit.kg-1.h-1, each dose for 30 min. Mean basal gallbladder volumes were not significantly different in the four experiments. Administration of cholecystokinin resulted in significant (p < 0.05) dose-dependent reductions in gallbladder volume in all experiments. During euglycaemia the gallbladder contraction in diabetic patients was not significantly different from the control subjects. During hyperglycaemia the gallbladder contraction in the diabetic patients was significantly (p < 0.05) reduced compared to euglycaemia only during infusion of 0.25 Ivy Dog Unit.kg-1.h-1 of cholecystokinin (19 +/- 6% vs 33 +/- 6%). Compared to euglycaemia, during hyperglycaemia the gallbladder contraction in the control subjects was significantly (p < 0.05) reduced during infusion of 0.25, 0.5 and 1.0 Ivy Dog Unit.kg-1.h-1 of cholecystokinin (14 +/- 4% vs 31 +/- 3%; 42 +/- 6% vs 65 +/- 5%; 74 +/- 4% vs 90 +/- 3%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Blood Glucose; Cholecystokinin; Diabetes Mellitus, Type 1; Female; Gallbladder; Glucagon; Glucose Clamp Technique; Humans; Hyperglycemia; Infusions, Intravenous; Male; Muscle Contraction; Muscle, Smooth; Pancreatic Polypeptide; Reference Values; Ultrasonography

The aim of the present study was to investigate the effect of acute hyperglycemia on (1) the intestinal phase of gallbladder contraction induced by the intraduodenal administration of emulsified fat, and (2) the small intestinal transit time measured by the lactulose breath hydrogen test. Six healthy volunteers were studied in random order during normoglycemia and hyperglycemia (blood glucose levels 15 mmol/liter). Gallbladder volumes were measured with ultrasonography. Administration of 1 and 2 g/hr of fat resulted in significant reductions in gallbladder volumes from 24 +/- 2 cm3 to 11 +/- 1 cm3 (P < 0.05) and 8 +/- 1 cm3 (P < 0.05), respectively during normoglycemia, and from 24 +/- 2 cm3 to 21 +/- 2 cm3 (P < 0.05) and 16 +/- 2 cm3, respectively (P < 0.05) during hyperglycemia. Compared to normoglycemia, the gallbladder contraction was significantly (P < 0.05) reduced during hyperglycemia. No significant differences in CCK secretion were observed between experiments. Small intestinal transit time during hyperglycemia (101 +/- 12 min) was significantly (P < 0.05) prolonged compared to normoglycemia (57 +/- 12 min). During hyperglycemia, basal PP levels and PP secretion in response to intraduodenal fat were significantly (P < 0.05) reduced compared to normoglycemia. It is concluded that (1) low doses of intraduodenal emulsified fat result in significant gallbladder contraction and CCK secretion, (2) acute hyperglycemia inhibits intraduodenal fat induced gallbladder contraction, (3) acute hyperglycemia does not affect the intraduodenal fat induced CCK secretion, (4) small intestinal transit is significantly prolonged during acute hyperglycemia, and (5) acute hyperglycemia inhibits basal and stimulated plasma PP secretion, suggesting impaired vagal-cholinergic tone during hyperglycemia.

Topics: Acute Disease; Adult; Cecum; Cholecystokinin; Duodenum; Gallbladder; Gastrointestinal Transit; Humans; Hyperglycemia; Male; Pancreatic Polypeptide; Ultrasonography; Vagus Nerve

The plasma cholecystokinin (CCK) response to a test meal was studied in 16 control subjects and 15 patients with noninsulin-dependent diabetes mellitus (NIDDM). Basal CCK levels were approximately 1 pmol in both groups. However, after the test meal, plasma CCK levels were 2-fold greater in the controls when compared to the diabetics. In controls, CCK levels maximally increased by 5.6 +/- 0.8 pmol (mean +/- SEM) 10 min after feeding, whereas in the NIDDM patients this value was 1.9 +/- 0.6 pmol (P < 0.001). After the test meal, the normal subjects showed no postprandial rise in blood glucose, whereas the diabetic patient showed a rise of 2.6 +/- 0.7 mmol. To determine whether the decreased CCK levels may have been related to the postprandial hyperglycemia, 7 diabetic subjects were infused with CCK. With this CCK infusion, postprandial glucose levels did not rise. These data suggest, therefore: 1) a role for cholecystokinin in regulating postprandial hyperglycemia in man, 2) abnormalities in CCK secretion occur in NIDDM and may contribute to the hyperglycemia seen in this disease.

Topics: Adult; Aged; Blood Glucose; Cholecystokinin; Diabetes Mellitus, Type 2; Female; Food; Humans; Hyperglycemia; Insulin; Male; Middle Aged

The purpose of this study was to investigate the effect of acute stable hyperglycemia on gallbladder motility, plasma cholecystokinin level and pancreatic polypeptide secretion. Gallbladder emptying in response to modified sham feeding and regular feeding was determined in six healthy subjects on two separate occasions during normoglycemia (serum glucose = 5 mmol/L) and during hyperglycemia (serum glucose = 15 mmol/L). Pancreatic polypeptide secretion was determined as an indirect measure of cholinergic tone. Gallbladder contraction in response to sham feeding during hyperglycemia (9% +/- 2%) was significantly (p < 0.05) reduced compared with that in normoglycemia (22% +/- 1%). During hyperglycemia, gallbladder emptying after meal ingestion (29% +/- 9%) was significantly (p < 0.05) less than that in normoglycemia (60% +/- 10%). Sham feeding did not affect plasma cholecystokinin levels. Regular feeding induced significant (p < 0.05) increases in plasma cholecystokinin levels in both experiments. However, integrated postprandial plasma cholecystokinin secretion was significantly (p < 0.05) reduced during hyperglycemia compared with that in normoglycemia (29 +/- 5 pmol.60 min vs. 58 +/- 10 pmol.60 min). Modified sham feeding-and feeding-stimulated pancreatic polypeptide secretion during hyperglycemia (235 +/- 95 pmol.90 min and 1,035 +/- 267 pmol.60 min, respectively) were significantly (p < 0.05) less than levels seen in normoglycemia (434 +/- 71 pmol.90 min and 1,961 +/- 219 pmol.60 min, respectively). This study indicates that gallbladder emptying and plasma hormone secretion in response to sham feeding and regular feeding are affected by blood glucose levels.

Topics: Adult; Cholecystokinin; Fasting; Food; Gallbladder Emptying; Humans; Hyperglycemia; Kinetics; Male; Pancreatic Polypeptide

Urinary levels of immunoreactive insulin (IRI) were measured in 18 pigs subjected to pancreatic allograft transplantation with exocrine drainage into the urinary tract. Fifteen pigs were given no immuosuppressive therapy while 3 pigs received cyclosporine and prednisolone. The onset of rejection was defined as an increase in the serum levels of anionic trypsin (irAT). Urinary levels of IRI were compared between normo- and hyperglycemic pigs representing slow and fast rejectors. It was possible to measure insulin in the urine from all these pigs with a pancreatic allograft, and the urinary IRI levels increased after an intravenous injection of secretion and cholecystokinin. We found that urinary IRI response to secretin and cholecystokinin declined during rejection. By contrast, baseline, unstimulated urinary IRI levels did not correlate with rejection. No advantage was seen in the determination of urinary IRI when compared to determination of urinary irAT. In pigs not treated with immunosuppressants (with irreversible rejection), stimulated urinary levels of IRI and irAT were highly useful as graft-function indicators, whereas in immunosuppressed pigs (with reversible rejection episodes) they seemed to complement each other.

Topics: Animals; Cholecystokinin; Graft Enhancement, Immunologic; Graft Rejection; Hyperglycemia; Immunosuppression Therapy; Insulin; Pancreas Transplantation; Secretin; Stimulation, Chemical; Swine; Trypsin

The effects of endogenous cholecystokinin (CCK) on insulin and pancreatic exocrine secretion were examined in conscious rats. Rats with bile and pancreatic fistulae, one duodenal cannula, and two jugular vein cannulae were divided into four groups, with and without glucose infusion (0.2 g/(ml.h)), and with bile and pancreatic juice (BPJ) diversion and return. Without glucose infusion, BPJ diversion did not have any significant effect on the plasma level of insulin or glucose; but with glucose infusion, it caused a significant increase in plasma insulin concentration 1 h after the diversion. The plasma glucose concentrations in the groups with BPJ diversion and return were not significantly different, and the response of pancreatic exocrine secretion to BPJ diversion was suppressed slightly, but not significantly, by glucose infusion. The plasma CCK concentration was increased significantly by BPJ diversion, but not affected by glucose infusion. These results indicate that, as observed in in vitro experiments with exogenous CCK, in conscious rats, endogenous CCK stimulates both exocrine and endocrine secretion of the pancreas, and that hyperglycemia is necessary for these effects to become apparent.

Topics: Animals; Bile; Blood Glucose; Cholecystokinin; Consciousness; Glucose; Hyperglycemia; Infusions, Intravenous; Insulin; Insulin Secretion; Male; Pancreas; Pancreatic Juice; Proglumide; Rats; Rats, Inbred Strains

Topics: Animals; Blood Glucose; Cholecystokinin; Glucose; Hyperglycemia; Injections, Intraventricular; Rats; Sincalide; Time Factors

Intracerebroventricular administration of cholecystokinin-octapeptide (CCK-8) in unanesthetized, unrestrained rats suppressed stress-induced eating and produced hyperglycemia. Prior adrenalectomy markedly reduced the hyperglycemia effect of intraventricular CCK-8 and also decreased the suppressive effect of CCK-8 on stress-induced eating. Our data are compatible with the anorectic effect of CCK-8 being secondary to the hyperglycemia it produces.

Topics: Adrenalectomy; Animals; Cholecystokinin; Eating; Hyperglycemia; Injections, Intraventricular; Male; Peptide Fragments; Rats; Rats, Inbred Strains; Sincalide; Stress, Physiological

Topics: Amylases; Animals; Carbamates; Cholecystokinin; Choline; Dinitrophenols; Epinephrine; Evaluation Studies as Topic; Fasting; Female; Homozygote; Hydrogen-Ion Concentration; Hyperglycemia; Kinetics; Maltose; Methods; Mice; Obesity; Pancreas; Phenotype; Secretin; Spectrophotometry; Time Factors

Topics: Animals; Cholecystokinin; Gastrins; Gastrointestinal Hormones; Hyperglycemia; In Vitro Techniques; Insulin; Insulin Secretion; Islets of Langerhans; Obesity; Secretin; Secretory Rate

Topics: Adult; Blood Glucose; Cholecystokinin; Diabetes Mellitus; Female; Glucagon; Hormones; Humans; Hyperglycemia; Insulin; Insulin Resistance; Insulin Secretion; Male; Middle Aged; Prediabetic State; Secretin; Tolbutamide

Hyperaminoacidemia is a powerful stimulus of pancreatic glucagon secretion. These studies were designed to elucidate the role of aminogenic hyperglucagonemia in glucoregulation. Conscious dogs with previously implanted indwelling venous catheters were employed. The results support the view that a role of glucagon is to limit blood glucose decline during hyperaminoacidemia.First, a significant negative correlation between the area of glucagon increment during the 1st 20 min of a 10 amino acid infusion and the maximum fall in glucose concentration was observed. Second, when endogenous glucagon secretion was suppressed by means of a continuous glucose infusion, hyperaminoacidemia induced a maximal glucose decline which averaged 35 mg/100 ml, differing significantly from mean maximal fall of 3 mg/100 ml, which normally occurs in the presence of endogenous hyperglucagonemia. Third, when, during hyperglycemic suppression of endogenous glucagon secretion, 50 mmug of exogenous glucagon/min was infused via the mesenteric vein with the amino acids, the fall in glucose was reduced to an average of 5 mg/100 ml. Similarly when pancreozymin, administered during the combined infusion of glucose and amino acids, overcame glucose suppression of endogenous glucagon secretion, plasma glucose did not fall. Similar results were obtained when aminogenic hyperglucagonemia was prevented by other means. Hyperlipacidemia, induced by infusing a triglyceride emulsion and giving heparin injections, also suppressed aminogenic hyperglucagonemia in two of four experiments; in these two dogs glucose fell 15 and 11 mg/100 ml. In a final group of experiments, the canine pancreas was resected except for the uncinate process, which is virtually devoid of alpha-cells. In two dogs, in which this procedure resulted in zero portal venous glucagon levels, the administration of amino acids and/or pancreozymin resulted in a glucose decline of 14 and 16 mg/100 ml, despite the reduced beta-cell population resulting from the subtotal pancreotectomy. It thus appears that the secretion of pancreatic glucagon during hyperaminoacidemia in association with insulin secretion, serves to limit the decline of glucose concentration.

Topics: Amino Acids; Animals; Blood Glucose; Catheterization; Cholecystokinin; Dogs; Glucagon; Homeostasis; Hyperglycemia; Lipids; Pancreas

Studies were carried out to determine if hyperaminoacidemia stimulates the secretion of pancreatic glucagon, and, if so, to evaluate the effect of endogenous and exogenous pancreozymin and of hyperglycemia upon this response. The intravenous administration to 16 dogs of 1 g/kg of a 10 amino acid mixture over a 60 min period raised amino nitrogen to a mean level of 13.5 mg/100 ml; mean pancreaticoduodenal vein insulin rose from 84 to 459 muU/ml and glucagon from 1.1 to 2.7 mmug/ml. Further augmentation of both insulin and glucagon secretion was achieved during hyperaminoacidemia by infusing pancreozymin. Since endogenous pancreozymin is known to be stimulated by amino acids in the gut, it seemed possible that intraduodenal loading of amino acids would elicit a greater insulin and glucagon response than could be explained by the accompanying hyperaminoacidemia. The intraduodenal administration of 1 g/kg of the amino acid mixture was followed by substantial hyperinsulinemia and hyperglucagonemia, which frequently anticipated the hyperaminoacidemia, and in many of the dogs the ratio of hormone rise to amino nitrogen rise was greater after intraduodenal than after the intravenous route of amino acid administration in the same animal. Intraduodenal administration of amino acids did not cause measurable release of intestinal glucagon-like immunoreactivity into the mesenteric vein plasma. Hyperglycemia induced by constant glucose infusion prevented aminogenic hyperglucagonemia and even suppressed the augmenting action of pancreozymin; sudden termination of the infusion with continued amino acid infusion was associated with a striking rise in glucagon. It is concluded (a) that hyperaminoacidemia stimulates pancreatic glucagon secretion, (b) that aminogenic hyperglucagonemia is augmented by the infusion of pancreozymin, (c) that intraduodenal administration of amino acids stimulates pancreatic glucagon secretion without measurable release of glucagon-like immunoreactivity into the mesenteric vein, and (d) that hyperglycemia prevents aminogenic hyperglucagonemia even during augmentation with pancreozymin. This conclusion suggests that the prevention of hypoglycemia during amino acid-induced insulin secretion may be an important function of glucagon.

Topics: Amino Acids; Animals; Blood Glucose; Cholecystokinin; Dogs; Duodenum; Glucagon; Hyperglycemia; Injections, Intravenous; Insulin; Male; Pancreas; Radioimmunoassay

The effects upon islet hormone secretion of highly purified preparations of secretin and of pancreozymin-cholecystokinin and of a crude gastrin-containing extract of hog antrum have been studied in acutely operated dogs. All three preparations were shown to cause a striking increase in insulin concentration in the pancreaticoduodenal venous plasma after their rapid endoportal injection in anesthetized dogs. With each hormone preparation, the peak in insulin secretion occurred 1 minute after injection, and a rapid decline was observed immediately thereafter. Whereas secretin and gastrin failed to alter significantly the pancreaticoduodenal venous glucagon or arterial glucose concentration, pancreozymin caused a dramatic rise in pancreaticoduodenal venous glucagon concentration, which reached a peak 3 minutes after injection, and hyperglycemia was noted to occur soon thereafter. Endoportal infusion of secretin and pancreozymin for 20 minutes caused responses that were sustained but qualitatively identical to the responses noted after rapid injection of the hormones. The beta-cytotropic effect of secretin was abolished by the infusion of epinephrine. These results could not be attributed to the small degree of contamination of the enteric hormone preparations with insulin or glucagon, and it would appear that secretin, pancreozymin, and probably gastrin have insulin-releasing activity and that pancreozymin has, in addition, glucagon-releasing activity.The demonstration that these three hormones possess insulin-releasing activity suggests that there is in the gastrointestinal tract a chain of betacytotropic hormones from antrum to ileum that is capable of augmenting insulin secretion as required for disposal of substrate loads. It is suggested that the existence of this "entero-insular axis" prevents high substrate concentrations that would otherwise follow ingestion of large meals were the insular response entirely a function of arterial substrate concentration.

Topics: Adrenocorticotropic Hormone; Animals; Blood Glucose; Cholecystokinin; Dogs; Epinephrine; Gastrins; Glucagon; Growth Hormone; Hyperglycemia; Insulin; Secretin; Vasopressins