Effect of acupuncture on serum PYY and nesfatin-1 in obese patients with insulin resistance / 针灸推拿医学（英文版）

Objective: To observe the effect of acupuncture on serum peptide YY (PYY) and nesfatin-1 in obese patients with insulin resistance. Methods: Ninety-eight obese patients with insulin resistance were divided into a control group and an observation group by the random number table method, with 49 cases in each group. The control group received exercise and dietary interventions, and the observation group received additional acupuncture treatment to the exercise and dietary interventions. The body mass index (BMI), body fat percentage, fasting insulin (FINS), fasting plasma glucose (FPG), homeostasis model assessment for insulin resistance (HOMA-IR), triglyceride (TG), total cholesterol (TC), and serum PYY and nesfatin-1 levels were compared before and after treatment. The efficacy was evaluated after treatment. Results: The total effective rate was significantly higher in the observation group than in the control group (P<0.05). After treatment, the BMI, body fat percentage, and serum TG and TC levels decreased significantly in both groups (P<0.05), and were significantly lower in the observation group than those in the control group (P<0.05). The FINS, FPG, HOMA-IR, and serum PYY and nesfatin-1 levels of the control group were not significantly changed after treatment (P>0.05). The FINS, FPG and HOMA-IR of the observation group decreased significantly after treatment (P<0.05), and were lower than those in the control group (P<0.05). The serum PYY and nesfatin-1 levels of the observation group increased significantly after treatment (P<0.05), and were higher than those in the control group (P<0.05). Conclusion: Based on exercise and dietary interventions, acupuncture is effective for obese patients with insulin resistance. It can reduce the BMI, body fat percentage, blood lipids, blood glucose, and serum insulin levels and improve insulin resistance. The action may be associated with the up-regulation of serum PYY and nesfatin-1.

Premeal Consumption of a Protein-Enriched, Dietary Fiber-Fortified Bar Decreases Total Energy Intake in Healthy Individuals

BACKGROUND: A premeal load of protein can increase satiety and reduce energy intake. Dietary fiber also conveys metabolic benefits by modulating energy intake. We made a protein-enriched, dietary fiber-fortified bar (PFB) and aimed to investigate its effects on food intake and gut hormone secretion in healthy individuals.METHODS: Twenty subjects with normal glucose tolerance were enrolled. On three separate visits, the subjects received, in a randomized order, one of the following: a PFB containing 73 kcal with 10.7 g of protein and 12.7 g of dietary fiber; a usual bar (UB) containing the same calories as the PFB but only 0.9 g of protein and no dietary fiber; or water (control). After 15 minutes, the subjects had ad libitum intake of a test meal. Food consumption, appetite, and plasma gut hormone levels were measured.RESULTS: Total energy intake, including the bar and the test meal, was significantly reduced with the PFB preload compared to the water (904.4±534.9 kcal vs. 1,075.0±508.0 kcal, P=0.016). With the UB preload, only the intake of the test meal was reduced (P=0.044) but not the total energy intake (P=0.471) than the water. Fullness was also significantly increased after the PFB. In addition, postprandial glucose levels decreased and glucagon-like peptide-1 levels increased with the PFB compared with both the UB and water.CONCLUSION: In healthy individuals, a premeal supplementation of PFB reduced total energy intake and decreased postprandial glucose excursion. This finding necessitates long-term studies regarding clinical use in obesity.

Sensitivity of plasma cholecystokinin and peptide YY in obese and normal weight men

@# Introduction: Cholecystokinin (CCK) and peptide YY (PYY) are satiety-stimulating hormones that are released during eating. As such, their levels may be used useful in obesity intervention. The aims of this study were to determine the optimal cutoff values, sensitivity and specificity of plasma CCK and PYY in adult men, in order to determine hormonal dysfunction in obesity. Methods: We investigated 16 obese [body mass index (BMI) ≥25.1)] and 16 normal weight (BMI 18.5–22.9) men. They ate isocaloric fast-food for breakfast. Blood for the determination of the hormones was collected at 0 (before), 30, 60, and 120 minutes after consumption. The data that was obtained were analysed using an independent t-test or the Mann– Whitney U-test. The receiver operating characteristic (ROC) curve was drawn and the trapezoidal rule analysis was performed to determine the area under the curve, to determine the optimal cut-off values, sensitivity and specificity. Results: In obese subjects, CCK was lower compared with normal weight subjects at any time (p<0.05). There were no major differences in PYY among subject groups. ROC curve analysis demonstrated that the plasma CCK had an optimal cut-off of 6,310 pg/ ml at 120 minutes after eating, with 0.97 area under curve (AUC), sensitivity was 94%, and specificity was 94%. The cut-off for optimal PYY was an average of 294.5 pg/ml at 120 minutes after eating (AUC 0.74; sensitivity 75%; specificity 75%). Conclusion: Our findings suggest that the plasma CCK level is a better potential predictor of obesity and constantly decreased over time compared to PYY.

Peptide YY producing strumal carcinoid tumor of the ovary in a postmenopausal woman: a rare cause of chronic constipation

Strumal carcinoid tumor of the ovary is a rare subtype of ovarian carcinoid tumors; it is characterized by an intimate mixture of thyroid and carcinoid tissues. We present a case of a 64-year-old woman who presented with the chief complaint of persistent, severe constipation for over 5 years; she was later found to have an ovarian strumal carcinoid tumor. Computed tomography showed a well-defined solid mass measuring 6.4 cm at the right adnexa. The patient underwent right salpingo-oophorectomy and was histopathologically diagnosed as having a strumal carcinoid tumor. Immunohistochemical examination showed immunoreactivity for peptide YY (PYY), which exerts an inhibitory effect on the peristaltic actions of the distal intestine. After surgery, the patient's constipation resolved rapidly, suggesting a correlation between PYY producing ovarian carcinoid tumor and constipation. This is the first case report of PYY producing primary strumal carcinoid tumor of the ovary associated with persistent, severe constipation from Korea.

Expression of inflammatory cytokines and its correlation with peptide YY and claudin-1 in patients with irritable bowel syndrome / 中华消化杂志

Objective To explore the pathogenesis of irritable bowel syndrome (IBS) by detecting serum levels and the colonic mucosa expression of inflammatory cytokines,peptide YY (PYY),and claudin-1,and to analyze their correlation.Methods From April 2013 to April 2015,50 outpatients with IBS and 20 healthy controls were selected.Serum levels of PYY,interleukin (IL)-10,tumor necrosis factor (TNF)-α and claudin-1 were detected by enzyme-linked immunosorbent assay (ELISA).The expression of IL-10,TNF-α,PYY and claudin-1 in colonic mucosa was determined by immunohistochemistry.Single factor analysis of variance,least significant difference (LSD) method,chi-square test,and Pearson correlation analysis were performed for statistical analysis.Results Among the 50 patients with IBS,27 cases were diarrhea-type irritable bowel syndrome (D-IBS),and 23 cases were constipated-type irritable bowel syndrome (C-IBS).The serum level and the positive expression rate of PYY in colonic mucosa of D-IBS group were significantly higher than those of healthy control group ((16.28± 2.75) ng/L vs (10.12± 1.55) ng/L;66.7 ％ (18/27) vs 30.0 ％ (6/20)),and the differences were statistically significant (LSD-t=10.19,x2 =6.182,both P＜0.05).The serum level and the positive expression rate of IL-10 in colonic mucosa of D-IBS group were both significantly lower than those of healthy control group ((2.95 ±0.24) ng/L vs (3.58±0.35) ng/L;22.2％(6/27) vs 50.0％ (10/20)),and the differences were statistically significant (LSD-t =4.52,x2=3.948,both P＜0.05).The serum level and the positive expression rate of TNF-α in colonic mucosa of D-IBS group were both significantly higher than those of healthy control group ((8.73±0.41) ng/L vs (7.73±0.51) ng/L;66.7％(18/27) vs 30.0％(6/20)),and the differences were statistically significant (LSD-t=8.43,x2 =6.182,both P＜0.05).There was no statistically significant difference between C-IBS group and healthy control group in the serum levels of PYY ((10.24±1.34) ng/L vs (10.12± 1.55) ng/L),IL-10 ((3.43 ± 0.71) ng/L vs (3.58 ± 0.35) ng/L),TNF-α ((7.81±0.26) ng/L vs (7.73 ±0.51) ng/L),and thus the positive expression rate in colonic mucosa (39.1％(9/23) vs 30.0％(6/20),56.5％(13/23) vs 50.0％(10/20),34.8％ (8/23) vs 30.0％(6/20);all P＞0.05).The serum level of claudin-1 and its positive expression rate of PYY,IL-10,TNF-α in colonic mucosa in D-IBS group were both lower than those of healthy control group ((94.44 ± 6.61) ng/Lvs (103.64 ± 5.47) ng/L;11.1％ (3/27) vs 40.0％ (8/20)),and the differences were statistically significant (LSD-t=5.76,x2 =5.349;both P＜0.05).However,the serum level of claudin-1 and its positive expression rate in colonic mucosa in C-IBS group were both higher than those of healthy control group ((115.54±3.42) ng/L vs (103.64±5.47) ng/L;73.9％ (17/23) vs 40.0％(8/20)),and the differences were statistically significant (LSD-t=5.56,x2 =5.055;both P＜0.05).The serum levels of IL-10 and PYY,TNF-α and claudin-1 were negatively correlated in the D-IBS group (r=-0.874 and -0.863,both P＜0.05).While the serum levels of TNF-α and PYY,IL-10 and claudin-1 were positively correlated (r =0.865 and 0.876,both P＜ 0.05).Conclusions There may be the imbalance of proinflammatory factors and anti-inflammatory factors in IBS patients.PYY may decrease the expression of claudin-1 by promoting IL-10 and inhibiting TNF-α,and thus ameliorate the inflammation reaction of IBS patients.

Influence of breast milk on secretion of Ghrelin and Peptide YY in rats / 中华实用儿科临床杂志

Objective To study the effect of breast milk on secretion of Ghrelin and Peptide YY (PYY)during different periods in SD rats.Methods Sprague-Dawley (SD) rats were randomly divided into breast milk-fed group(BG) and formula-artificial fed group(FG) with 20 in each group.After 21 days both of the 2 groups were fed by same forage.Ten of each group were experimentized in day 21 equivalently weaning period,and rest rats were experimentized at the 50th day equivalently childhood.Real-time PCR was used to determine the mRNA of PYY,Ghrelin from gastric,colon.Immunohistochemistry was used to determine Ghrelin,PYY protein expression in the gastrointestinal tract tissues.Results There were no difference between body weight and gastrointestinal mucosal development of 2 rat groups in day 21 and day 50(P ＞0.05),mRNA and protein expression of Ghrelin and PYY in breast milk-fed group were higher than formula-artificial fed group in both day 21 and day 50 (all P ＜ 0.05).Conclusions The Ghrelin and PYY levels of breast milk-fed rats is higher than formula-artificial fed ones,and this phenomenon continues to their childhood.Breast milk protects offspring from obesity by influencing the secretion of brain-gut peptide and has long-term consequences on the regulation of food intake and energy balance from neonatal period to their later life.

Correlations of circulating peptide YY and ghrelin with body weight, rate of weight gain, and time required to achieve the recommended daily intake in preterm infants

The objective was to elucidate the relationships between serum concentrations of the gut hormone peptide YY (PYY) and ghrelin and growth development in infants for potential application to the clinical observation index. Serum concentrations of PYY and ghrelin were measured using radioimmunoassay from samples collected at the clinic. For each patient, gestational age, birth weight, time required to return to birth weight, rate of weight gain, time required to achieve recommended daily intake (RDI) standards, time required for full-gastric feeding, duration of hospitalization, and time of administration of total parenteral nutrition were recorded. Serum PYY and ghrelin concentrations were significantly higher in the preterm group (N = 20) than in the full-term group (N = 20; P < 0.01). Within the preterm infant group, the serum concentrations of PYY and ghrelin on postnatal day (PND) 7 (ghrelin = 1485.38 ± 409.24; PYY = 812.37 ± 153.77 ng/L) were significantly higher than on PND 1 (ghrelin = 956.85 ± 223.09; PYY = 545.27 ± 204.51 ng/L) or PND 3 (ghrelin = 1108.44 ± 351.36; PYY = 628.96 ± 235.63 ng/L; P < 0.01). Both serum PYY and ghrelin concentrations were negatively correlated with body weight, and the degree of correlation varied with age. Serum ghrelin concentration correlated negatively with birth weight and positively with the time required to achieve RDI (P < 0.05). In conclusion, serum PYY and ghrelin concentrations reflect a negative energy balance, predict postnatal growth, and enable compensation. Further studies are required to elucidate the precise concentration and roles of PYY and ghrelin in newborns and to determine the usefulness of measuring these hormones in clinical practice.

Short-Term Effects of Ratio of Energy Nutrients on Appetite-Related Hormones in Female College Students

Understanding the relationship between energy nutrients compositions in a diet and appetite-controlling substances is essential for providing sound advice to anyone attempting to control body weight. Appetite is known to be affected by various hormones, ghrelin and peptide tyrosine-tyrosine (PYY), which are related to the compositions of a diet. The purpose of this study was to investigate the effects of compositions of energy nutrients in the diet on the levels of postprandial appetite-related hormones and satiety in healthy adult women. Ten subjects (BMI: 18.5-22.9 kg/m2) were recruited and assigned to three iso-coloric breakfast meals with different compositions of energy nutrients, regular meal (RM, CHO: 60%, Pro: 20%, Fat: 20%), high protein meal (HPM, CHO: 30%, Pro: 50%, Fat: 20%), and high fat meal (HFM, CHO: 30%, Pro: 20%, Fat: 50%). Blood levels of ghrelin, PYY, insulin and leptin and satiety were assessed at baseline, 30, 60, 90, 120, and 180 min following the consumption of each meal. There was no significant difference in the fasting blood hormones among the subjects taking each meals at baseline. Blood levels of ghrelin and insulin changed significantly following the consumption of each meal (p<0.05) over time, however no significant difference was shown between experimental meals until 180 min. Blood levels of PYY and leptin were not changed following the ingestion of each meals. In conclusion, the composition of energy nutrients in a diet had no effect on the postprandial plasma levels of ghrelin, PYY, insulin and leptin as well as satiety in healthy adult women.

Plasma ghrelin and peptide YY levels in patients with type 2 diabetes before and after metformin treatment / 中华内分泌代谢杂志

Objective To investigate the effects of metformin on plasma ghrelin and peptide YY (PYY)levels in newly-diagnosed type 2 diabetic patients,and to study the impact of metformin on body weight.Methods A prospective nested case-control study was designed as a research protocol.Sixty four newly-diagnosed type 2 diabetic patients were treated with metformin for 12 weeks.The patients were divided into two groups:weight loss group and non-weight loss group according to the changes in body weight after metformin treatment.Fasting plasma ghrelin and PYY levels and other metabolic parameters were measured before and after metformin treatment.ResultsFasting plasma ghrelin level was significantly decreased in the patients after metformin treatment [ ( 10.71 ±2.68 vs 11.81 ±3.19 )ng/ml,P＜0.05 ].Fasting plasma PYY level was significantly increased in patients after metformin treatment [ ( 136.86+39.14 vs 128.42+37.31 ) pg/ml,P＜0.05 ].After metformin treatment,43.7％ of the patients lost body weight significantly.Fasting plasma ghrelin level was decreased by 16.6％ after treatment in the weight loss group,as compared with 6.2％ in non weight loss group( P＜0.05 ).Fasting plasma PYY level was increased by 10.8％ after treatment in the weight loss group,as compared with 3.5％ in the non-weight loss group (P ＜ 0.05 ).Conclusions The fasting plasma ghrelin level in the weight loss group was lowered more significantly compared with that in the non-weight loss group after metformin treatment.The fasting plasma PYY level in the weight loss group was elevated more significantly as compared with that in the non-weight loss group after metformin treatment.The mechanism remains to be further studied.

Mechanism of Action of Cholecystokinin on Colonic Motility in Isolated, Vascularly Perfused Rat Colon

BACKGROUND/AIMS: It is generally believed that cholecystokinin (CCK) stimulates colonic motility, although there are controversial reports. It has also been suggested that postprandial peptide YY (PYY) release is CCK-dependent. Using a totally isolated, vascularly perfused rat colon, we investigated: (1) the roles of CCK and PYY on colonic motility, (2) to determine if CCK modulates PYY release from the colon to influence the motility and (3) to clarify whether the action of CCK and PYY on colonic motility is mediated via the influence of cholinergic input. METHODS: An isolated whole rat colon was used. Luminal pressure was monitored via microtip catheter pressure transducers from proximal and distal colon. After a control period, CCK-8 or PYY was administerd intraarterially with or without an anti-PYY serum, loxiglumide or atropine at 12, 60 and 240 pM. Each dose was given for a period of 15-minute and the contractile response was expressed as % changes over basal. PYY concentration in the portal effluent was determined by radioimmunoassay. RESULTS: Exogenous CCK-8 increased colonic motility which paralleled the increase in PYY release in the portal effluent. Exogenous PYY also significantly increased colonic motility although it was less potent than CCK. The stimulating effect of CCK-8 was significantly inhibited by an anti-PYY serum, and was completely abolished by loxiglumide, and almost completely abolished by atropine. CONCLUSIONS: CCK increases colonic motility via CCK1 receptor and it is mediated partly by PYY. Cholinergic input is required for the increased motility by either PYY or CCK.

Effect of Roux-en-Y Gastric Bypass on Body Weight, Ghrelin and PYY(3-36) in Diet-induced Obese Rats

PURPOSE: Obesity is considered an epidemic worldwide. Nonsurgical treatment such as dietary, physical and pharmacological therapies have limited success and thus, bariatric surgery is the ultimate option. Roux-en-Y gastric bypass (RYGB) is a bariatric procedure, which is a restrictive and malabsorptive procedure simultaneously. The purpose of this study was to develop surgical rat models of bariatric surgery and analyze the effect of gastric bypass on body weight, ghrelin and polypeptide YY(3-36) (PYY(3-36)) changes in rats. METHODS: RYGB, sleeve gastrectomy (SG) and sham operation were performed in diet-induced obese rats and compared to obese control and normal control rats. RESULTS: In RYGB group, 20.7+/-8.56% of weight loss was achieved on postoperative day 18 and maintained thereafter. This outcome was significant compared to SG (8.8+/-1.82%) and sham operated (6.2+/-2.45%) groups. When pre- and postoperative ghrelin levels were compared, there was a significant decrease in RYGB group (P<0.028); nonetheless, there was no difference in SG and sham operated groups. When pre- and postoperative PYY(3-36) levels were compared, there was a significant increase in RYGB (P<0.028), SG (P<0.031) and sham operated (P<0.031) groups. CONCLUSION: We developed surgical rat models of RYGB and SG. Those rats that underwent RYGB lost significant body weight and maintained the weight thereafter. The decrease in ghrelin and increase in PYY(3-36) may be associated with loss of appetite and delay in intestinal transit time with subsequent weight loss maintenance. In the future, this rat model would serve as a tool for further study on endocrine regulation of obesity.

Effects of PYY on the interdigestive migrating myoelectric complex in the small intestine in vivo and the neural and endocrinal mechanisms of the effects / 药物分析学报

Objective To investigate the effects of peptide YY (PYY) on the interdigestive migrating myoelectrlc complex (MMC) in the small intestine in vivo and explore the neural and endecrinal mechanisms of the effects. Methods Spragne-Dawley rats were supplied with a venous catheter and bipolar electrodes in the duodenum and jejunum for electromyography of stomach and small intestine in wake state. PYY, phentolamine, nitro-L-arginine (L-NNA, the inhibitor of nitric oxide synthase) and atropine were served with PYY respectively. The plasma motilin levels before and after the infusion of PYY were observed. Results At all the three recording points, PYY lengthened the drde length of MMC [from (591.90±128.98)s to (999.25±216.59)s, P<0. 01] and lowered the frequency of phase Ⅲ [from (39.28±8.40) min-1 to (22.08±3.13) min-1 , P<0.01], amplitude of phase Ⅲ [from (0. 320±0.060)mV to (0. 179±0.030)mV, P<0.01], and the portion of phase Ⅲ over the whole circle length [from (28. 61 ± 5.84)% to (15.43 ±5.16)% , P<0.01]. Phentolumine had no influence on the role of PYY. Administered L-NNA combined with PYY, the percentage of phase Ⅲ increased [(42. 09±8.67)%] compared with that of control(P<0.01) and compared with that of PYY administered alone (P<0. 01) too. Atropine combined with PYY showed stronger depressing effects on MMC. No significant difference was found between the plasma motilin levels before and after the infusion of PYY. Conclusion PYY my inhibit the interdigestive intestine motility through the none-adrenergic none-choUnergic tract, while the m-receptor tract and circulating motilin are probably not involved In the depressing effect.

Effects of PYY on the interdigestive migrating myoelectric complex in the small intestine in vivo and the neural and endocrinal mechanisms of the effects / 西安交通大学学报·英文版

Objective: To investigate the effects of peptide YY (PYY) on the interdigestive migrating myoelectric complex (MMC) in the small intestine in vivo and explore the neural and endocrinal mechanisms of the effects. Methods: Sprague-Dawley rats were supplied with a venous catheter and bipolar electrodes in the duodenum and jejunum for electromyography of stomach and small intestine in wake state. PYY, phentolamine, nitro-L-arginine (L-NNA, the inhibitor of nitric oxide synthase) and atropine were served with PYY respectively. The plasma motilin levels before and after the infusion of PYY were observed. Results: At all the three recording points, PYY lengthened the circle length of MMC [from (591.90±128.98)s to (999.25±216.59)s, P<0.01] and lowered the frequency of phase III [from (39.28±8.40) min-1 to (22.08±3.13) min-1, P<0.01], amplitude of phase III [from (0.320±0.060)mV to (0.179±0.030)mV, P<0.01], and the portion of phase III over the whole circle length [from (28.61±5.84)% to (15.43±5.16)%, P<0.01]. Phentolamine had no influence on the role of PYY. Administered L-NNA combined with PYY, the percentage of phase III increased [(42.09±8.67)%] compared with that of control (P<0.01) and compared with that of PYY administered alone (P<0.01) too. Atropine combined with PYY showed stronger depressing effects on MMC. No significant difference was found between the plasma motilin levels before and after the infusion of PYY. Conclusion PYY may inhibit the interdigestive intestine motility through the none-adrenergic none-cholinergic tract, while the α-receptor tract and circulating motilin are probably not involved in the depressing effect.

Different Regulation of Atrial ANP Release through Neuropeptide Y2 and Y4 Receptors

Neuropeptide Y (NPY) receptors are present in cardiac membranes. However, its physiological roles in the heart are not clear. The aim of this study was to define the direct effects of pancreatic polypeptide (PP) on atrial dynamics and atrial natriuretic peptide (ANP) release in perfused beating atria. Pancreatic polypeptides, a NPY Y4 receptor agonist, decreased atrial contractility but was not dose-dependent. The ANP release was stimulated by PP in a dose-dependent manner. GR 23118, a NPY Y4 receptor agonist, also increased the ANP release and the potency was greater than PP. In contrast, peptide YY (3-36) (PYY), an NPY Y2 receptor agonist, suppressed the release of ANP with positive inotropy. NPY, an agonist for Y1, 2, 5 receptor, did not cause any significant changes. The pretreatment of NPY (18-36), an antagonist for NPY Y3 receptor, markedly attenuated the stimulation of ANP release by PP but did not affect the suppression of ANP release by PYY. BIIE0246, an antagonist for NPY Y2 receptor, attenuated the suppression of ANP release by PYY. The responsiveness of atrial contractility to PP or PYY was not affected by either of the antagonists. These results suggest that NPY Y4 and Y2 receptor differently regulate the release of atrial ANP.

Peptide YY, Cholecystokinin, Insulin and Ghrelin Response to Meal did not Change, but Mean Serum Levels of Insulin is Reduced in Children with Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a contiguous gene syndrome characterized by uncontrollable eating or hyperphagia. Several studies have confirmed that plasma ghrelin levels are markedly elevated in PWS adults and children. The study of anorexigenic hormones is of interest because of their regulation of appetite by negative signals. To study the pattern and response of the anorexigenic hormones such as cholecystokinin (CCK) and peptide YY (PYY) to a meal in PWS, we measured the plasma CCK, PYY, ghrelin and serum insulin levels in PWS patients (n=4) and in controls (n=4) hourly for a day, and analyzed hormone levels and hormonal responses to meals. Repeated measures of ANOVA of hormone levels demonstrated that only insulin levels decreased (p=0.013) and CCK (p=0.005) and ghrelin (p=0.0007) increased in PWS over 24 hr. However, no significant group x time interactions (ghrelin: p=0.89, CCK: p=0.93, PYY: p=0.68 and insulin: p=0.85) were observed; in addition, there were no differences in an assessment of a three-hour area under the curve after breakfast. These results suggest that the response pattern of hormones to meals in PWS patients parallels that of normal controls. In addition, the decrease of insulin levels over 24 hr, in spite of obesity and elevated ghrelin levels, suggests that the baseline insulin level, not the insulin response to meals, may be abnormal in patients with PWS.

Interaction of Dietary Composition and PYY Gene Expression in Diet-induced Obesity in Rats / 华中科技大学学报（医学）（英德文版）

Summary: The interaction of high-fat diet and the peptide YY (PYY) gene expression in diet-induced obesity and the mechanisms which predisposed some individuals to become obese on high-fat diet were explored. Thirty-six male SD rats were randomly divided into high-fat diet group (n=27) and chow fed control group (n=9). After 15 weeks of either a high-fat diet or chew fed diet, the high-fat diet group was subdivided into dietary induced obesity (DIO) and dietary induced obesity resistant (DIR) group according to the final body weight. Then the DIO rats were subdivided into two groups for a 8-week secondary dietary intervention. One of the group was switched to chew fed diet, whereas the other DIO and DIR rats continued on the initial high-fat diet. Weight gain and food intake were measured, food efficiency was calculated, and the concentrations of plasma neuropeptide Y (NPY) and PYY were assayed. Hypothalamic NPY mRNA expression and PYY mRNA expression in ileum and colon was detected by RT-PCR. The results showed that at the end of 15th week, the levels of body weight and caloric intake were significantly higher in DIO group than in DIR or control group (P<0.01), while no significant difference was found between DIR and control group (P>0.05). The concentration of plasma PYY was significantly higher in DIR group than in DIO and CF group, while no significant difference was found between DIO and CF group (P<0.01). After switching the DIO rats to chow fed diet, their body weight gains were significantly lower than that of the DIO-HF group. The expression of PYY mRNA was increased in DIO-HF/CF rats than in DIO-HF rats, and the expression of hypothalamic NPY mRNA was decreased in DIO-HF/CF rats than in DIO-HF group. It was concluded that both dietary composition and PYY gene expression could potently alter the hypothalamic NPY expression and result in different susceptibility to obese and overeating. The decreased PYY was associated with the increased NPY expression and their predisposal to obese and overeating in rats.

Determination of the serum level and receptors' characteristics of peptide YY in rats with irritable bowel syndrome / 西安交通大学学报(医学版)

0.05). Conclusion IBS may be related to the changes of the serum level of PYY,but not to the changes of PYY receptor.

Distribution and characters of peptide YY receptor in rat jejunum epithelial cell / 西安交通大学学报(医学版)

Objective To detect normal rat jejunum epithelial cells to learn about the distribution of peptide YY(PYY)receptor and measured two important parameters of PYY receptor so as to explore the target that PYY binds to and display its physiological function.Methods Receptor radioligand assay was conducted by using 125I-PYY to detect normal rat jejunum epithelial cells.We also measured receptor dissociation constant(Kd),the affinity or the ability that the receptor could bind ligand;maximum binding capacity(Bmax),the concentration of binding site;and Hill coefficient.Results There were PYY receptors in normal rat jejunum epithelial cells.Dissociation constant(Kd)of PYY receptor was(386.69?129.95)pmol/L.Maximum binding capacity(Bmax)was(303.21?116.85)fmol/mg protein.Hill coefficient was 1.PYY receptor had high affinity.Conclusion There are distributions of PYY receptors in normal rat jejunum epithelial cells.Kd means that PYY receptor has high affinity.Bmax means that the number of receptors is limited and decides the characters of saturability.We think that PYY directly inhibits secretion by binding to PYY receptor in jejunum epithelial cells when PYY inhibiting jejunum secretion.