neuropeptide-y and Kidney-Failure--Chronic

I review recent knowledge on the interference of neuropeptide Y with energy balance and cardiovascular and renal disease and on the central regulation of bone mass.. Although neuropeptide Y is mainly seen as a vasoconstrictor, rats overexpressing the neuropeptide Y gene show reduced blood pressure and longer life span in comparison with control rats. Due to its strong mitogenic effects on vascular smooth muscle cells, neuropeptide Y induces occlusive lesions in a rat model of atherosclerosis induced by balloon angioplasty. The involvement of neuropeptide Y in experimental atherosclerosis is complex and may include also favourable, compensatory, mechanisms because, at physiological concentrations, it also activates a potent neoangiogenic response to ischemia. Subjects with a common genotype in the neuropeptide Y gene, which underlies increased intracellular neuropeptide Y storage, display slightly raised blood pressure, high serum cholesterol and increased carotid intima media thickness. In patients with end-stage renal disease high neuropeptide Y in plasma has been associated consistently with concentric left-ventricular hypertrophy and cardiovascular mortality. Finally, recent studies have shown that neuropeptide Y constitutes an important central regulator of bone mass and that it may be involved in inflammation and immune regulation.. Evidence has accrued in experimental animals that altered neuropeptide Y is involved in obesity and the attendant metabolic complications. Recent data also suggest that this peptide may play a role in atherosclerosis and related cardiovascular complications.

Topics: Animals; Body Weight; Bone and Bones; Cardiovascular Diseases; Energy Metabolism; Humans; Hypertrophy, Left Ventricular; Kidney Failure, Chronic; Neuropeptide Y; Rats

Topics: Humans; Kidney Failure, Chronic; Neuropeptide Y; Sympathetic Nervous System

We have studied the effects of handgrip on plasma levels of catecholamines, neuropeptide Y (NPY), and leu-enkephalin before and after hemodialysis of uremic patients. A cuprophan dialyzer was used. We found, that dopamine level was higher in uremia group before hemodialysis both during rest (0.38 +/- 0.39 pmol/ml) and handgrip (1.13 +/- 1.00 pmol/ml) compared to control (0.17 +/- 0.19, and 0.66 +/- 0.83 pmol/ml respectively). Hemodialysis leads to further increase of its level (0.49 +/- 0.35 pmol/ml) at rest. Epinephrine level was almost the same in uremic patients before (0.43 +/- 0.51 pmol/ml) and after dialysis (0.46 +/- 0.60) as in control subjects (0.41 +/- 0.37 pmol/ml) during the rest. Its level measured after the handgrip was the highest in uremic group after dialysis (2.10 +/- 2.00 pmol/ml), significantly lower before dialysis (1.26 +/- 0.85 pmol/ml), and the lowest in control group (0.78 +/- 0.43 pmol/ml). Norepinephrine level were very similar in uremic group before dialysis (1.54 +/- 1.05 pmol/ml), after dialysis (1.79 +/- 1.29 pmol/ml) and in control group (1.46 +/- 1.06 pmol/ml) during the rest. During the handgrip test its level was higher in uremic group after hemodialysis than before it (adequate values 8.78 +/- 4.61 and 6.70 +/- 4.74 pmol/ml). The difference between uremia group before dialysis and control group did not reach significance. The level of NPY has the tendency to increase in uremic patients. Dialysis leads to following increase of its level, but the changes did not reach the significance both in rest and handgrip. Leu-enkephalin level was higher in uremic group (9.21 +/- 7.62 pmol/ml) compared to control (5.22 +/- 1.53 pmol/ml). We observed non-significant fall of this level after dialysis (6.79 +/- 4.76 pmol/ml). We found the same tendency during the handgrip, and the changes were significant.. uremia per se leads to increase the level of dopamine and leu-enkephaline during the rest and handgrip, but the level of epinephrine only during the handgrip; dialysis leads to further increase of dopamine during the rest, but epinephrine, norepinephrine and leu-enkephaline only during the handgrip.

Topics: Adult; Enkephalin, Leucine; Exercise; Female; Hand Strength; Humans; Kidney Failure, Chronic; Male; Neuropeptide Y; Renal Dialysis; Rest; Uremia

Neuropeptide Y (NPY) is a sympathetic neurotransmitter that acts on multiple receptors involved in cardiovascular remodelling and angiogenesis. Plasma levels of NPY are increased in patients with end-stage renal disease (ESRD) and are independently related to left ventricular hypertrophy (LVH) and incident cardiovascular events in these patients.. To investigate the relationship between NPY receptor Y2 gene polymorphism and left ventricular mass index (LVMI) as well as the interaction between this polymorphism and plasma NPY in determining LVH in 189 ESRD patients.. LVMI was significantly higher (+12%, P = 0.03) in patients carrying the C allele than in those without C allele and was linearly associated with plasma NPY (P = 0.01). Interaction analysis showed a significant NPY-LVMI relationship in patients with the C allele, both at univariate (r = 0.27, P = 0.001) and multivariate (r = 0.21, P = 0.01) analyses, whereas no such relationship existed in patients without this allele. In fully adjusted analyses, a 10 pmol/l increase in plasma NPY entailed a 4.9 g/m increase in LVMI in patients with C allele, whereas the same change in NPY levels did not modify the NPY-LVMI link in patients without such allele (P = 0.009).. NPY receptor Y2 polymorphism is independently associated with LVMI and interacts with plasma levels of NPY in explaining the variability of LVH in ESRD. These results offer a genetic basis to the hypothesis that NPY is causally implicated in the pathogenetic pathway leading to LVH in ESRD patients.

Topics: Comorbidity; Female; Genetic Predisposition to Disease; Humans; Hypertrophy, Left Ventricular; Italy; Kidney Failure, Chronic; Logistic Models; Male; Middle Aged; Neuropeptide Y; Polymorphism, Single Nucleotide; Receptors, Neuropeptide Y; Renal Dialysis

To investigate the effect of Shenshuai Yangzhen Capsule (SYC) on hypothalamic leptin-neuropeptide Y (NPY) and proopiomelanocortin (POMC) axes in chronic renal failure (CRF) rats with malnutrition (MN).. Forty-two male SD rats of SPF grade were established into CRF-MN model by 5/6 nephrectomy and 4% casein diet, the happening time of MN in them was recorded. Rats successfully modeled were randomized into three groups, 11 rats in Group A treated with SYC, 11 in group B treated with composite alpha-keto acid and 12 in Group C was untreated. Besides, a normal control group was set up with 8 healthy rats. After being treated for 4 weeks, the renal function related indices, including serum creatinine (Scr), blood urea nitrogen (BUN), 24 hour urine protein (24 h Upro), albumin (ALB), haemoglobin (Hb) insulin like growth factor-1 (IGF-1), total cholesterol (TC) and triglyeride (TG) were measured, and body weight, food intake in rats were observed dynamically, blood leptin and NPY level in rats were determined by radioimmunoassay; mRNA expressions of OB-Rb, NPY and POMC in hypothalamus were detected with RT-PCR.. CRF rats revealed MN at the end of 10th week after modeling. Compared with Group C, the condition of MN in Group A was significantly improved, showing increase of food intake and body weight (P < 0.05), marked improvement of renal function (P < 0.05), decrease of LP and NPY levels in plasma (P < 0.05), as well as up-regulated NPY mRNA expression and down-regulated mRNA expressions of OB-Rb and POMC in hypothalamus (P < 0.01).. SYC can improve the malnutrition condition in rats with CRF, which is possibly by way of depressing OB-Rb and POMC mRNA expression and upgrading NPY mRNA expression in hypothalamus.

Topics: Animals; Drugs, Chinese Herbal; Hypothalamus; Kidney Failure, Chronic; Leptin; Male; Malnutrition; Neuropeptide Y; Pro-Opiomelanocortin; Rats; Rats, Sprague-Dawley; RNA, Messenger

To study the influence of different blood purification technology on plasma leptin and neuropeptide Y (NPY).. 150 patients with chronic renal failure in our hospital were included, which were divided into hemodialysis (HD) group, hemoperfusion (HP) group, and hemofiltration (HF) group. The serum leptin and neuropeptide Y levels were measured by radioimmunoassay (RIA) before and after first treatment, after treatment for 3, 6 month.. Serum leptin and NPY were significantly lower after HDF and HP (P < 0.05), but not after HD in single treatment and for 3, 6 months treatment (P > 0.05). Serum leptin and NPY in group HDF and HP patients in single treatment and for 3, 6 months treatment were significantly greater than those of group HD (P < 0.05). The clearance rate of leptin and NPY in group HDF and HP patients were significantly greater than those of group HD (P < 0.05). There is no correlation between serum leptin and NPY (P > 0.05).. Hemodialysis can not lower serum leptin and NPY. But HDF and HP can eliminate serum leptin and NPY preferably, which may improve the patients' nutritional status.

Topics: Adult; Aged; Aged, 80 and over; Female; Hemofiltration; Hemoperfusion; Humans; Kidney Failure, Chronic; Leptin; Male; Middle Aged; Neuropeptide Y; Renal Dialysis

To investigate the effects of alpha-keto acid on the expression of neuropeptide Y in malnutrition rats with chronic renal failure.. SD rats received 5/6 nephrectomy and were fed with 4% casein to establish models of malnutrition with chronic renal failure. Serum albumin, urea nitrogen, serum creatinine, type-1 insulin like growth factor and body weight of the rats were measured. The rat models were randomized into chronic renal failure group, alpha-keto acid group and normal control group, and after a 4-week treatment as indicated, neuropeptide Y mRNA levels in the hypothalamus were measured by RT-PCR in rats with surgically induced renal failure (two-stage subtotal nephrectomy). The blood neuropeptide Y of the rats were analyzed by radioimmunoassay.. Malnutrition occurred in chronic renal failure rats at the end of 10 weeks. Compared with those in the chronic renal failure group, the plasma neuropeptide Y concentrations in alpha-keto acid group were significantly lowered with substantially elevated neuropeptide Y mRNA expression in the hypothalamus.. alpha-keto acid capsule can improve malnutrition in rats with renal insufficiency possibly by up-regulating neuropeptide Y mRNA expression in the hypothalamus and reducing the level of blood neuropeptide Y.

Topics: Animals; Hypothalamus; Keto Acids; Kidney Failure, Chronic; Male; Malnutrition; Neuropeptide Y; Rats; Rats, Sprague-Dawley; RNA, Messenger

Anorexia is possibly one of the most important causes of malnutrition in uremic patients. The cause of this abnormality is still unknown. Considering that: (a) NPY is one of the most important stimulants of food intake; (b) eating is a central nervous system regulated process and (c) NPY is expressed in hypothalamus, we hypothesized that the decrease of NPY gene expression in the hypothalamus could be an important factor contributing to anorexia associated with uremic state. In contrast to the prediction, the results presented in this paper indicate that the NPY gene expression in the hypothalamus of chronic renal failure (CRF) rats was significantly higher than in the hypothalamus of control (pair-fed) rats. Moreover, we found that serum NPY concentration in CRF rats was higher than in control (pair-fed) animals. The increase of plasma NPY concentration in CRF rats may be due to the greater synthesis of the neuropeptide in liver, since higher level of NPY mRNA was found in liver of CRF rats. The results obtained revealed that experimental chronic renal failure is associated with the increase of NPY gene expression in hypothalamus and liver of rats.

Topics: Animals; Anorexia; Disease Models, Animal; Gene Expression Regulation; Hypothalamus; Kidney Failure, Chronic; Liver; Male; Neuropeptide Y; Rats; Rats, Wistar; RNA, Messenger; Up-Regulation

In mice, neuropeptide Y (NPY) decreases bone turnover by means of a parathyroid hormone-independent effect on osteoblast activity.. Cross-sectional study.. We studied the relationship between levels of NPY and biomarkers of osteoblast activity in 161 nondiabetic patients with end-stage renal disease (131 patients, hemodialysis; 30 patients, continuous ambulatory peritoneal dialysis).. We performed an analysis of demographic and clinical variables associated with NPY as a dependent variable and a second analysis testing the association of NPY (as an independent variable) with markers of osteoblast activity.. Peritoneal dialysis as treatment modality (beta = 0.37; P < 0.001) and longer duration of dialysis therapy (beta = 0.24; P < 0.01) were independently related to plasma NPY. NPY level was related inversely (P < 0.001) to serum alkaline phosphatase and bone alkaline phosphatase levels (P = 0.01). The NPY-alkaline phosphatase link was confirmed in a multiple regression analysis adjusting for a series of potential confounders, including parathyroid hormone. In a categorical analysis in which the study population was divided according to NPY quartiles, the proportion of patients with low alkaline phosphatase levels was lowest in the first 2 NPY quartiles (26%) and highest in NPY quartile 4 (80%; P < 0.001), and this association held true in a multiple logistic regression analysis, indicating that the risk of low alkaline phosphatase level increases in parallel with NPY level.. The hypothesis generated by this cross-sectional study needs to be confirmed in cohort studies.. The inverse relationships between levels of NPY and biomarkers of bone turnover support the hypothesis that NPY may be implicated in low bone turnover in dialysis patients by a central parathyroid-independent mechanism.

Topics: Aged; Alkaline Phosphatase; Biomarkers; Bone and Bones; Bone Diseases; Cross-Sectional Studies; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged; Neuropeptide Y; Osteoblasts; Peritoneal Dialysis; Regression Analysis; Renal Dialysis

To study anorexia in chronic renal failure (CRF) patients, we measured appetite-related hormones in seven CRF patients and four controls. Plasma concentrations and fractional changes from baseline (values from day 1, 0800) are listed as control vs. CRF (means +/- SE). Leptin, although higher in CRF (5.6 +/- 1.7 and 34 +/- 17 ng/ml), was suppressed after fasting; decrements were -51 +/- 9 and -55 +/- 8%. Nocturnal surge present during feeding was abolished upon fasting in both groups. Neuropeptide Y (NPY) was elevated in CRF (72 +/- 12 vs. 304 +/- 28 pg/ml, P = 0.0002). NPY rhythm, reciprocal to that of leptin, was muted in CRF. Basal cortisol was similar in both groups (17 +/- 3 and 17 +/- 2 microg/dl). In the controls, cortisol peaked in the morning and declined in the evening. CRF showed blunted cortisol suppression. Decrements were -61 +/- 3 and -20 +/- 9% at 1800 on day 1 (P = 0.008) and -61 +/- 8 and -26 +/- 8% at 2000 on day 2 (P = 0.02). Basal ACTH (25 +/- 5 and 54 +/- 16 pg/ml) as well as diurnal pattern was not statistically different between the groups. Baseline insulin was 6 +/- 1 and 20 +/- 9 microU/ml. During fasting, insulin was suppressed to -64 +/- 10 and -51 +/- 9%, respectively. Upon refeeding, increments were 277 +/- 96 and 397 +/- 75%. Thus, in our CRF patients, anorexia was not due to excess leptin or deficient NPY. Impaired cortisol suppression should favor eating. Insulin suppression during fasting and secretion after feeding should enhance both eating and anabolism. The constant high NPY suggests increased tonic hypersecretion.

Topics: Adrenocorticotropic Hormone; Adult; Appetite; Blood Glucose; Eating; Fasting; Female; Humans; Hydrocortisone; Insulin; Kidney Failure, Chronic; Leptin; Male; Middle Aged; Neuropeptide Y

Haemodialysed patients with chronic renal failure are characterized by elevated plasma neuropeptide Y (NPY) concentration. Successful kidney transplantation is followed by a regression of the uraemic state and normalization of hormonal and metabolic abnormalities. The aim of the present study was to assess the influence of successful kidney transplantation on plasma NPY concentration in patients with chronic renal failure.. A total of 38 patients with chronic renal failure was examined after successful kidney transplantation. The control group consisted of 33 healthy subjects. In kidney transplant recipients plasma NPY concentration was assessed immediately before kidney transplantation and additionally two times after successful kidney transplantation: 2-4 days after surgical procedure and just before discharge of the patient from the hospital, when the graft excretory function was satisfactory. At the days specified above blood samples for NPY estimation were withdrawn at 8.00 am, 4.00 pm and 12.00 pm.. Plasma NPY concentration in patients before kidney transplantation was significantly (p<0.001) higher than in healthy subjects. Plasma NPY concentration assessed at 8.00 am, 4.00 pm and at 12.00 pm both 2-4 days after kidney transplantation and one day before discharge of the patient from hospital was significantly higher than in healthy subjects (p<0.001). Plasma NPY concentration in kidney transplant patients just before discharge of the patient from hospital did not differ from 2-4 days after surgical procedure. Both in graft recipients and in healthy individuals no significant diurnal changes in NPY plasma concentration were noticed. No significant correlation was found between plasma NPY concentration and blood pressure in kidney transplant patients and in healthy subjects.. As successful kidney transplantation does not normalize plasma NPY concentration in the early posttransplant period, implies that the transplanted kidney with good excretory functions and immunosupressive therapy are not essential factors involved in the maintence of elevated NPY plasma level in the early posttransplant period.

Topics: Adult; Case-Control Studies; Circadian Rhythm; Female; Humans; Kidney Failure, Chronic; Kidney Transplantation; Male; Neuropeptide Y; Osmolar Concentration; Postoperative Period; Time Factors

Neuropeptide Y (NPY) is released during sympathetic stimulation and mediates the central effects of the adipostatic hormone leptin. The plasma concentration of NPY and leptin is increased in patients with end stage renal disease (ESRD), but it is unknown whether these substances are related to biochemical markers of sympathetic activity and to alterations in left ventricular (LV) mass and function in these patients.. We investigated the relationship between NPY, norepinephrine (NE), leptin and echocardiographic measurements in a cross-sectional study in 198 patients with ESRD.. NPY was directly related to plasma NE and heart rate but it was largely independent of arterial pressure and of retention of metabolic waste products. NPY was significantly higher in patients with LV hypertrophy and in those with LV systolic dysfunction than in those without these alterations. Of note, NPY emerged as an independent correlate of LV mass index and of LV ejection fraction (LVEF) (both P

Topics: Adult; Aged; Biomarkers; Cohort Studies; Cross-Sectional Studies; Echocardiography; Female; Humans; Hypertrophy, Left Ventricular; Kidney Failure, Chronic; Leptin; Male; Middle Aged; Myocardium; Neuropeptide Y; Norepinephrine; Risk Factors; Ventricular Dysfunction, Left

To explore the changes of orexin A and neuropeptide (NPY) in plasma and hypothalamus of rats with chronic renal failure (CRF).. 41 male Wister rats weighing 200 approximately 250 g were randomly divided into three groups: normal group, sham operation group, and CRF group (with the right kidney and 2/3 of the left kidney resected). A certain number of rats were decapitated 4, 8,and 12 weeks after respectively. Their hypothalami were removed and blood collected. Radioimmunoassay was used to measure the levels of orexin A and NPY in hypothalamus and plasma. Automatic biochemical analyzer was used to measure the serum creatinine.. The serum creatinine level of CRF rats was both significantly higher than those of the sham operation rats at week 8 and week 12, respectively. The plasma orexin A level of CRF rats at week 12 was 264 pg/ml +/- 62 pg/ml, significantly higher than that of sham operation group (183 pg/ml +/- 56pg/ml, P = 0.039). The hypothalamus orexin A level of CRF rats were 10.5 fmol/mg +/- 2.7 fmol/mg wet weight at week 12, significantly lower than that of sham operation rats (17.4 fmol/mg +/- 3.9 fmol/mg wet weight, P = 0.023). The plasma NPY levels of CRF rats at week 8 and week 12 were significantly higher than those of the sham operation rats (7.1 pmol/ml +/- 1.7 pmol/ml vs 5.0 pmol/ml +/- 0.5 pmol/ml, P = 0.01; and 7.9 pmol/ml +/- 1.1 pmol/ml vs 4.8 pmol/ml +/- 1.1 pmol/ml, P = 0.0008). The hypothalamus NPY level of CRF rats at week 12 were 70 fmol/mg +/- 23 fmol/mg wet weight, significantly lower than that of the sham operation rats (113 fmol/mg +/- 31 fmol/mg wet weight, P = 0.03).. Loss of renal function may diminish the excretion of orexin A and neuropeptide. The lowering of hypothalamus orexin A and neuropeptide Y levels may be one of the causes inducing anorexia in CRF.

Topics: Animals; Carrier Proteins; Hypothalamus; Intracellular Signaling Peptides and Proteins; Kidney Failure, Chronic; Male; Neuropeptide Y; Neuropeptides; Orexins; Rats; Rats, Wistar

Chronic renal insufficiency is a situation characterized by high plasma concentration of neuropeptide Y (NPY). Because this neuropeptide interferes with cardiovascular (CV) function, it is possible that it is involved in the high CV-related morbidity and mortality of these patients. To test this hypothesis, a follow-up study was performed (average duration, 34 mo; range 0.2 to 52.0 mo) in a cohort of 277 patients with end-stage renal disease receiving chronic dialysis. Univariate analysis revealed that plasma NPY was directly related to plasma norepinephrine (r = 0.37, P < 0.001) and epinephrine (r = 0.17, P = 0.005), exceeding the upper limit of the normal range in the majority of patients with end-stage renal disease (170 of 277, 61%). One hundred thirteen patients had one or more fatal and nonfatal CV events; 112 patients died, 66 of them (59%) of CV causes. Plasma NPY failed to predict all-cause mortality but was an independent predictor of adverse CV outcomes (hazard ratio [10 pmol/L increase in plasma NPY], 1.32; 95% confidence interval, 1.09 to 1.60; P = 0.004) in a Cox proportional-hazard model that included a series of traditional and nontraditional CV risk factors. Plasma NPY maintained its predictive power for CV events in statistical model including plasma norepinephrine. Plasma NPY predicts incident CV complications in end-stage renal disease. Controlled trials are needed to establish whether interference with the sympathetic system, NPY, or both may reduce the high CV morbidity and mortality of dialysis patients.

Topics: Adult; Aged; Biomarkers; Cardiovascular Diseases; Epinephrine; Female; Follow-Up Studies; Humans; Incidence; Kidney Failure, Chronic; Male; Middle Aged; Neuropeptide Y; Norepinephrine; Predictive Value of Tests; Prospective Studies; Risk Factors; Survival Analysis; Urea; Uremia

The aim of this study was to investigate the change of neuropeptide Y(NPY) content and neurotensin (NT) content of the platelet from chronic renal failure (CRF) patients during hemodialysis (HD) and explore its mechanism of action. Platelet was separated from the patients' plasma and the NPY and and NT contents of the platelet and plasma were dynamically observed pre-HD and post-HD. 30 healthy people were chosen as the controls. The results showed the NPY and NT contents of the platelet extract were (58.18 +/- 21.29) ng/10(9) and (25.38 +/- 13.43) ng/10(9) respectively. The NPY content of the platelet extract of the CRF patients was obviously decreased and the NT content of the plasma was obviously increased however, the NT contents of the platelet extract and the plasma were both higher than those in the control group. The NPY content of the platelet extract and NT content of the plasma at the post-HD obviously increased as compared with pre-HD, but the NT content of the platelet extract and the NPY content of the plasma obviously decreased. There was an obvious correlation between NPY and NT. The authors conclude that during the period of CRF, the immunoreactions which mainly involve bio-active substances such as NPY, NT and 5-hydroxytryptamine released by the platelet to interfer the vasoconstrictive effect are the main pathologic factors to induce renal hypertensin and renal vasospasm.

Topics: Adult; Blood Platelets; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged; Neuropeptide Y; Neurotensin; Renal Dialysis

Leptin and neuropeptide Y (NPY) seem to play an important role in food intake and energy expenditure. Leptin is secreted by adipose tissue in proportion fo fat stores and is presumed to be an important anorectic hormone. NPY is produced by the hypothalamus, and in contrast to leptin, is one of the most potent appetite stimulants yet demonstrated. On the other hand, in most patients increased appetite is present after successful kidney transplantation. Finally, a stimulatory effect of glucocorticoids on leptin secretion was reported. The present study aimed to assess the relationship between plasma leptin and NPY levels and body mass index (BMI) in haemodialyzed patients (HDP) with chronic renal failure and in kidney transplant patients (KTP). In both groups, BMI was of the same magnitude as in healthy controls. Despite the presence of a normal BMI, leptin levels in KTP (25.2 +/- 3.6 ng/ml) and in HDP with chronic renal failure (25.3 +/- 4.2 ng/ml) were higher than in controls (11.7 +/- 1.8 ng/ml). The mean plasma NPY level in KTP (168.0 +/- 10.3 pg/ml) was significantly higher (p < 0. 01) than in controls (70.7 +/- 5.9 pg/ml) and in HDP (77.0 +/- 5.7 pg/ml). In all examined groups, a significant positive correlation was found between leptinaemia and BMI.. (1) KTP are characterized by significantly elevated leptinaemia in spite of a normal BMI. In KTP this increased leptinaemia does not seem to be dependent only upon the fat mass and the kind and dosis of immunosuppressive therapy. (2) Similarly to healthy subjects, female KTP and HDP show markedly higher leptinaemia than males. (3) In contrast to healthy subjects and HDP, KTP are characterized by significantly elevated plasma NPY levels.

Topics: Adult; Body Mass Index; Creatinine; Female; Humans; Kidney Failure, Chronic; Kidney Transplantation; Leptin; Male; Neuropeptide Y; Proteins; Renal Dialysis; Statistics, Nonparametric

Neuropeptide Y (NPY) is a peptide hormone that is expressed, stored, and released in sympathetic neurones together with noradrenaline. Elevated plasma concentrations of NPY have been reported in patients with neural crest tumors (neuroblastoma, pheochromocytoma) and following exercise. We studied plasma concentrations of NPY in children and adults with chronic and terminal renal failure and compared them with those in healthy controls. Neuropeptide Y was significantly higher in children and adolescents receiving peritoneal dialysis (5.3 +/- 2.8 pmol/L; n = 11 [mean +/- SD]) or hemodialysis (5.4 +/- 2.1 pmol/L; n = 14) than in healthy children (2.3 +/- 0.9 pmol/L; n = 19) or pediatric patients with impaired renal function who are not receiving dialysis (2.7 +/- 0.6 pmol/L; n = 8; mean glomerular filtration rate, 41 mL/min x 1.73 m2). There was a small but insignificant negative correlation between glomerular filtration rate and NPY concentrations in children with impaired renal function (r = 0.49; P = 0.25). In healthy adults, NPY concentration was similar to that in healthy children (1.8 +/- 1.0 pmol/L; n = 13), and it was significantly elevated in adults receiving hemodialysis (5.9 +/- 1.7 pmol/L; n = 16). No significant changes in NPY concentrations were found before and after hemodialysis in pediatric or adult patients. We conclude that plasma concentrations of NPY are elevated in patients with chronic renal failure who are receiving either peritoneal or hemodialysis, but not in patients with moderately impaired renal function. Whether elevated NPY concentration indicates increased sympathetic activity or is caused by reduced NPY clearance remains to be shown.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Female; Humans; Infant; Kidney Failure, Chronic; Male; Middle Aged; Neuropeptide Y; Renal Dialysis

Blood pressure regulation during intermittent hemodialysis treatment involves many different mechanisms. Eight normotensive patients without antihypertensive drugs on intermittent hemodialysis treatment, mean age 50 years, were studied with 24-hour blood pressure measurements. Atrial natriuretic peptide (ANP) and neuropeptide Y (NPY) were determined concomitantly. Eight control individuals matched for age and sex were investigated in the same way. A significant increase of both systolic and diastolic blood pressure, heart rate and pathological circadian rhythm was seen among the dialysis patients. High levels of ANP were found before and after dialysis. NPY showed steady state levels through the 24 hours and did not differ between the two groups. Overhydration is a probable cause of the disturbed blood pressure regulation and increased ANP-values.

Topics: Adult; Aged; Atrial Natriuretic Factor; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged; Neuropeptide Y; Peptides; Renal Dialysis

During bicarbonate hemodialysis, there is an increase in peripheral vascular resistance of nonadrenergic origin, counteracting the hypotensive effect of fluid removal during the course of the dialysis. In this study, the plasma levels of vasoactive regulatory peptides, noradrenaline and renin, were investigated in 11 patients with chronic renal failure during standard bicarbonate hemodialysis (STHD) for 270 min. As regards vasoconstrictors, an increase in gamma 2-melanocyte-stimulating hormone (gamma 2-MSH), neuropeptide Y (NPY) and plasma renin activity (PRA) occurred. However, arginine vasopressin and noradrenaline were unchanged. With respect to vasodilators, calcitonin gene-related peptide was not changed. An initial increase in beta-endorphin (beta-END) occurred, followed by a decrease during the remaining part of the treatment. Motilin decreased during the first part of the treatment but increased to the baseline level during the latter part. An increase in substance P was observed while vasoactive intestinal peptide decreased. We conclude that an increase in vasoconstricting substances (gamma 2-MSH, NPY, PRA) occurs during STHD, probably owing to the decrease in plasma volume. With the exception of beta-END, the changes in vasodilators were fairly small. The data suggest that vasoactive substances might participate in the hemodynamic response to hemodialysis.

Topics: Adult; Aged; Aged, 80 and over; Arginine Vasopressin; beta-Endorphin; Bicarbonates; Calcitonin Gene-Related Peptide; Female; Hemodynamics; Humans; Hypotension; Kidney Failure, Chronic; Male; Melanocyte-Stimulating Hormones; Middle Aged; Neuropeptide Y; Neuropeptides; Norepinephrine; Renal Dialysis; Renin

The hemodynamic response to isolated ultrafiltration (IUF) is characterized by a vasoconstriction, while there is no significant change in peripheral vascular resistance during isovolemic bicarbonate hemodialysis (IVHD). The present investigation was designed to study the plasma levels of vasoactive regulatory peptides together with noradrenaline (NA) and plasma renin activity (PRA) in 11 patients during sequential hemodialysis (SQHD) - IUF for 60 min, followed by IVHD for 210 min. During IUF, the vasoconstrictors arginine vasopressin (AVP), gamma 2-melanocyte-stimulating hormone (gamma 2-MSH), neuropeptide Y (NPY), NA and PRA increased. During IVHD, NPY and PRA remained unchanged on a higher level. A decrease in AVP below the baseline and in gamma 2-MSH and NA to the baseline levels occurred during IVHD. In the case of vasodilators, there were no changes in calcitonin gene-related peptide or motilin during SQHD. An increase in beta-endorphin (beta-END) occurred during IUF, followed by a decrease during IVHD. Substance P and vasoactive intestinal peptide were unchanged during IUF but decreased during IVHD. We conclude that SQHD is characterized by an increase in all the measured vasoconstrictors during IUF in response to loss of fluid, and by a decrease in some vasoconstrictors (AVP, gamma 2-MSH, NA) during IVHD. With the exception of beta-END, there were no changes or only minor ones in vasodilators during SQHD. There are changes in plasma levels of vasoactive substances during SQHD but the importance of these changes for the hemodynamic adaptation to ultrafiltration and dialysis needs to be studied further.

Topics: Adult; Aged; Aged, 80 and over; Arginine Vasopressin; beta-Endorphin; Bicarbonates; Female; Hemodynamics; Humans; Kidney Failure, Chronic; Male; Melanocyte-Stimulating Hormones; Middle Aged; Neuropeptide Y; Neuropeptides; Norepinephrine; Renal Dialysis; Renin; Ultrafiltration

1. We investigated the usefulness of neuropeptide Y as a plasma marker for phaeochromocytoma, ganglioneuroblastoma and neuroblastoma using a simple and highly sensitive r.i.a. for human neuropeptide Y. 2. Plasma immunoreactive neuropeptide Y concentrations were measured without extraction in plasma samples (100 microliters) from patients with various diseases. 3. The plasma immunoreactive neuropeptide Y concentration in patients with phaeochromocytoma (172.3 +/- 132.4 pmol/l, mean +/- SD, n = 23) was significantly higher than that in healthy adult subjects (40.1 +/- 10.1 pmol/l, n = 40, P < 0.0001). The plasma immunoreactive neuropeptide Y concentrations in patients with ganglioneuroblastoma (590.7 +/- 563.6 pmol/l, n = 6) and patients with neuroblastoma (566.9 +/- 524.4 pmol/l, n = 15) were significantly higher than those in control children (1-9 years old, 82.2 +/- 39.9 pmol/l, n = 72, P < 0.0001). 4. The plasma immunoreactive neuropeptide Y concentration in patients with essential hypertension (34.0 +/- 3.7 pmol/l, n = 18) was within the normal range, but in patients with chronic renal failure undergoing maintenance haemodialysis (192.1 +/- 68.0 pmol/l, n = 25) and in non-dialysed patients with chronic renal failure (85.1 +/- 23.1 pmol/l, n = 7) it was significantly higher than that in healthy adult subjects (P < 0.0001). 5. Eighty-seven per cent of the patients with phaeochromocytoma, 67% of the patients with ganglioneuroblastoma and 80% of the patients with neuroblastoma showed plasma immunoreactive neuropeptide Y concentrations higher than the upper limits in the control subjects [62 pmol/l (adult) and 160 pmol/l (children)].(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adolescent; Adrenal Gland Neoplasms; Adult; Aged; Biomarkers, Tumor; Child; Child, Preschool; Female; Ganglioneuroma; Humans; Hypertension; Infant; Kidney Failure, Chronic; Male; Middle Aged; Neuroblastoma; Neuropeptide Y; Pheochromocytoma; Radioimmunoassay

The fasting plasma levels of 10 vasoactive regulatory peptides were measured by radioimmunoassay in 23 stable patients with chronic renal failure receiving regular hemodialysis treatment (RDT) and compared with those of healthy controls. The plasma concentrations of arginine vasopressin, atrial natriuretic peptide, beta-endorphin, methionine-enkephalin, motilin, neuropeptide Y, substance P, and vasoactive intestinal peptide were increased. The plasma level of calcitonin gene-related peptide was not statistically different from that of the controls. The plasma concentration of gamma 2-melanocyte-stimulating hormone was lowered in the RDT-patients. The arterial blood pressure correlated with the plasma levels of motilin and neuropeptide Y. We conclude that patients with chronic renal failure receiving RDT have increased concentrations of 8 out of 10 measured vasoactive regulatory peptides. The elevated levels of vasoactive peptides may contribute to the adaptation of the cardiovascular system to impaired renal function.

Topics: Adult; Aged; Aged, 80 and over; Arginine Vasopressin; Atrial Natriuretic Factor; beta-Endorphin; Blood Pressure; Enkephalin, Methionine; Female; Humans; Kidney Failure, Chronic; Kidney Function Tests; Male; Middle Aged; Motilin; Neuropeptide Y; Neuropeptides; Renal Dialysis; Substance P; Vascular Resistance; Vasoactive Intestinal Peptide

A second antibody solid phase radioimmunoassay for measuring neuropeptide Y (NPY) in biological fluids is introduced. The sensitivity of the method allows also measurements of sub-normal levels of plasma/serum NPY, necessary for obtaining further information of possible biological actions of circulating NPY. Characteristics of the NPY assay procedure are presented together with clinical experiments forced upon a possible renal dependence for NPY. Our data show that NPY at least partly is eliminated by the kidneys. Whether the highly increased NPY levels in patients with renal failure also are involved in the hypertensive mechanisms in these patient groups has to be further evaluated.

Topics: Adrenal Gland Neoplasms; Adult; Body Fluids; Chromatography, High Pressure Liquid; Humans; Kidney; Kidney Failure, Chronic; Middle Aged; Neuropeptide Y; Pheochromocytoma; Radioimmunoassay; Reference Values

To investigate the clinical usefulness of radio-immunoassay of neuropeptide Y (NPY), we measured plasma immunoreactive neuropeptide Y (IR-NPY) concentrations in normal subjects (n = 21), essential hypertensive patients (n = 33), patients with phaeochromocytoma (n = 7), patients with chronic renal disease with serum creatinine levels of less than 1.9 mg/dl (n = 5) and patients with chronic renal failure whose serum creatinine levels were greater than or equal to 1.9 mg/dl (n = 18, eight without haemodialysis and 10 undergoing maintenance haemodialysis), by radio-immunoassay. Plasma IR-NPY concentrations in patients with phaeochromocytoma (577 +/- 256 pg/ml, mean +/- s.d.) were significantly higher (P less than 0.001) than those in normal subjects (151 +/- 28 pg/ml), essential hypertensive patients (177 +/- 49 pg/ml) and patients with chronic renal disease with serum creatinine levels less than 1.9 mg/dl (198 +/- 71 pg/ml). Plasma IR-NPY concentrations in patients with chronic renal failure (without haemodialysis: 330 +/- 63 pg/ml; undergoing maintenance haemodialysis: 374 +/- 80 pg/ml) were also high. These results suggest that NPY is useful as one of the tumour markers of phaeochromocytomas. However, this study revealed that patients with chronic renal failure, without phaeochromocytoma also have increased plasma IR-NPY concentrations.

Topics: Adrenal Gland Neoplasms; Adult; Chromatography, Gel; Creatinine; Female; Humans; Hypertension; Kidney Failure, Chronic; Male; Middle Aged; Neuropeptide Y; Pheochromocytoma; Radioimmunoassay; Renal Dialysis