cholecystokinin and Hypocalcemia

Gastrointestinal hormones containing the C-terminal tetrapeptide of gastrin are involved in calcium homeostasis. The aim of this study was to investigate: 1) the effect of a standard meal (schedule a) and of a duodenal infusion of 5% aminoacid solution (schedule b) on calcium, CT and PTH serum levels in man; 2) the behaviour of these parameters during I.V. infusions of pentagastrin (mcg 1.5/Kg-hour), sincalide (mcg 0.04/Kg-hour) and caerulein (ng 75/Kg-hour) (schedule c). In order to avoid any possible interference by endogenous secretin release, schedule c was performed in 5 patients previously submitted to total gastrectomy. Schedule a and b were studied in 5 healthy volunteers. After a standard meal a slight increase of CT and PTH was measured. Duodenal infusion of aminoacid was followed by hypocalcaemia and slight but constant rise of CT levels, without significant variations of circulating PTH. Pentagastrin, sincalide and caerulein induced a slight but significant hypocalcaemia and a rise of serum CT levels, together with a significant increase of serum PTH. These findings suggest that peptides containing the C-terminal tetrapeptide of gastrin directly affect calcium homeostasis in the absence of secretin release.

Topics: Amino Acids; Calcitonin; Calcium; Ceruletide; Cholecystokinin; Clinical Trials as Topic; Eating; Enteral Nutrition; Hormones; Humans; Hyperparathyroidism; Hypocalcemia; Infusions, Parenteral; Parathyroid Hormone; Pentagastrin; Sincalide

Two boys with idiopathic hypoparathyroidism had extensive studies of gastrointestinal function during hypocalcemia accompanied by steatorrhea. No evidence of generalized gastrointestinal moniliasis or abnormal mucosal structure or function was observed. Studies of pancreatic function and bile salt metabolism during hypocalcemia demonstrated deficient meal-stimulated intraluminal pancreatic enzyme concentrations in both subjects and reduced bile salt concentrations in one subject. However, following stimulation with exogenous octapeptide of cholecystokinin, intraluminal pancreatic enzyme and bile salt concentrations were normal in both. Cholic acid pool sizes were markedly increased in both subjects during hypocalcemia (9 and 12 times larger than during normocalcemia) and cholic acid turnover was reduced during hypocalcemia in one subject. Our findings suggest that during hypocalcemia, insufficient endogenous cholecystokinin is released by the duodenal mucosa during a meal stimulus to stimulate normal gallbladder contraction and pancreatic enzyme secretion.

Topics: Adolescent; Bile Acids and Salts; Celiac Disease; Child; Cholecystokinin; Cholic Acid; Cholic Acids; Digestion; Humans; Hypocalcemia; Hypoparathyroidism; Male; Pancreatin; Peptide Fragments; Sincalide

Topics: Animals; Calcium; Cholecystokinin; Hypocalcemia; Male; Rats

Topics: Animals; Calcitonin; Calcium; Cholecystokinin; Edetic Acid; Female; Gastric Mucosa; Hypercalcemia; Hypocalcemia; Pancreas; Rats; Secretin; Stimulation, Chemical; Time Factors; Trypsin

Topics: Acute Disease; Adult; Amylases; Bicarbonates; Calcitonin; Cholecystokinin; Female; Humans; Hypercalcemia; Hypocalcemia; Male; Middle Aged; Pancreas; Secretin; Trypsin

Topics: Acute Disease; Calcium; Celiac Disease; Cholecystography; Cholecystokinin; Chronic Disease; Clinical Enzyme Tests; Exocrine Glands; Glucose Tolerance Test; Humans; Hypocalcemia; Hypoparathyroidism; Male; Middle Aged; Pancreatitis; Radionuclide Imaging; Secretin; Triglycerides