Fasting ghrelin but not PYY(3-36) is associated with insulin-resistance independently of body weight in Wistar rats / A grelina, mas não PYY(3-36), está associada com a resistência à insulina independente do peso corporal em ratos Wistar

Objective: The objective of this study was to evaluate the association between insulin-resistance and fasting levels of ghrelin and PYY in Wistar rats. Materials and methods: A total of 25 male Wistar rats, weighing 200-300 g, was included in this study. The animals were maintained in cages with a 12/12h light-dark cycle and fed standard chow and water ad libitum. After 12-h overnight fasting, ghrelin, PYY, insulin and glucose values were determined. Insulin resistance was assessed by means of the HOMA-IR, which was ranked and the median was used as a cut-off value to categorize insulin-resistance. HOMA-IR values equal and above 2.62 were considered insulin-resistant (IR) while values below 2.62 were considered insulin sensitive (IS). Differences between means were determined using the Student t-test. Multiple regression and Pearson’s correlation test were used to evaluate the association between variables. Results: HOMA-IR median IQ range values for IS and IR groups were, respectively, 1.56 (0.89 – 2.16) vs. [4.06 (3.50 – 4.61); p < 0.001]. The IR group presented increased levels of fasting ghrelin, PYY and insulin respectively: [50.35 (25.99 – 74.71) pg/mL vs. 12.33 (8.77 – 15.89) pg/mL; p = 0.001]; [54.38 (37.50 – 71.26) pg/mL vs. 33.17 (22.34 – 43.99) pg/mL; p = 0.016]; [18.04 (14.48 – 21.60) uU/mL vs. 7.09 (4.83 – 9.35) uU/mL; p = 0.001]. Ghrelin, but not PYY, correlated linearly and positively with HOMA-IR: ghrelin vs. HOMA-IR (r = 0.52; p = 0.008), and PYY vs. HOMA-IR (r = 0.22; p = 0.200). This correlation was independent of body weight. Conclusion: Fasting ghrelin and PYY serum levels are increased in lean, relatively insulin resistant Wistar rats, and this increase is independent of weight. .

Objetivo: O objetivo deste estudo foi avaliar a associação entre a resistência à insulina e os níveis de grelina e PYY em jejum em ratos Wistar. Materiais e métodos: Um total de 25 ratos Wistar machos, pesando 200-300 g, foi usado neste estudo. Os animais foram mantidos em gaiolas com um ciclo de luz escuro de 12/12h e alimentados com ração padrão e água ad libitum. Depois de um jejum de 12h, os valores de grelina, PYY, insulina e glicose foram determinados. A resistência à insulina foi avaliada pelo HOMA-IR que foi ordenado e a mediana utilizada como valor de corte para categorizar a resistência à insulina. Os valores de HOMA-IR iguais ou acima de 2,62 foram considerados resistentes à insulina (RI), enquanto valores abaixo de 2,62 foram considerados sensíveis (SI). As diferenças entre as médias foram determinadas usando-se o teste t de Student. A análise de regressões múltiplas e o teste de correlação de Pearson foram usados para se avaliar a associação entre as variáveis. Resultados: A mediana e a variação IQ do HOMA-IR para os grupos RI e SI foram, respectivamente, 1,56 (0,89 – 2,16) contra [4,06 (3,50 – 4,61); p < 0,001]. O grupo RI apresentou níveis aumentados de grelina, PYY e insulina em jejum, respectivamente, [50,35 (25,99 – 74,71) pg/mL contra 12,33 (8,77 – 15,89) pg/mL; p = 0,001]; [54,38 (37,50 – 71,26) pg/mL contra 33,17 (22,34 – 43,99) pg/mL; p = 0,016]; [18,04 (14,48 – 21,60) uU/mL contra 7,09 (4,83 – 9,35) uU/mL; p = 0.001]. A grelina, mas não PYY, se correlacionou de forma linear e positiva com o HOMA-IR: a grelina contra HOMA-IR (r = 0,52; p = 0,008), e PYY contra HOMA-IR (r = 0,22; p = 0,200). Essa correlação foi independente do peso corporal. Conclusão: Os níveis séricos de jejum de grelina ...

Gastrectomía vertical por laparoscopia "Manga gástrica" / Laparoscopic sleeve gastrectomy

La obesidad mórbida es, después del cigarrillo, la causa de mayor mortalidad prevenible en el mundo entero. Es una patología crónica de manejo interdisciplinario en la que la cirugía bariátrica hace parte fundamental del tratamiento, ya que logra, más que cualquier otro, la disminución y mantenimiento del peso con el propósito de resolver y/o mejorar las comorbilidades secundarias. Dentro del armamento quirúrgico se encuentra la gastrectomía vertical o manga gástrica, procedimiento que ha demostrado ser fisiológico, efectivo y seguro en el manejo de esta enfermedad. Hoy día no se trata de un procedimiento únicamente restrictivo, sino que conlleva a cambios hormonales con respecto a las hormonas orexigénicas como la ghrelina y en otras como la GLP1 y en el PYY. Su morbilidad y mortalidad quirúrgica es muy baja y sus excelentes resultados hasta el momento son de gran importancia dentro de la cirugía bariátrica.

Morbid obesity is the second leading preventable cause of death after cigarette smoking in the world. It is a chronic pathology which requires interdisciplinary management in which bariatric surgery plays a fundamental part. It results in greater weight loss and better maintenance of weight loss than any other treatment in the effort to resolve or diminish secondary comorbidities associated with morbid obesity. One of the surgical tools used for this surgery is sleeve gastrectomy (vertical gastrectomy). This procedure has demonstrated itself to be physiological, effective, and safe for management of this disease. These days it is considered to be a procedure restricted only by the hormonal changes it brings about in orexigenic hormones such as ghrelin, glucagon-like peptide-1 (GLP1) and peptide YY (PYY). Morbidity and mortality rates for this surgery are very low, but surgical results to date are excellent. This has moved sleeve gastrectomies into an important place within bariatric surgery.

Appetite-related hormone levels in obese women with and without binge eating behavior / Hormônios reguladores do apetite em mulheres obesas com e sem compulsão alimentar

OBJECTIVE: The aim of this study was to evaluate serum levels of appetite-related hormones (peptide YY3-36, total ghrelin, leptin and insulin) before and after consumption of a meal in obese women with and without binge eating episodes and normal weight women. METHODS: Twenty-five women aged 32-50 years were invited to participate in this study, including 9 normal weight women without binge eating episodes (20-25kg/m², group 1), 9 obese women with binge eating episodes (³30kg/m², group 2), and 7 obese women without binge eating episodes (group 3). Four blood samples were collected from each participant, one being 60 minutes before and three being 15, 45 and 90 minutes after a meal. The composition of the meal was 55 percent carbohydrates, 15 percent protein and 30 percent lipids. RESULTS: Group 3 presented increased HOMA-IR (M=2.5, SD=1.04) when compared with group 1 (M=1.5, SD=0.53) and group 2 (M=1.8, SD=0.58), p=0.04. Body mass index (p<0.0001), leptin (p<0.0001) and insulin (p=0.01) were higher in group 3 than in the other groups before and after the meal. Additionally, total ghrelin (p=0.003) and PYY3-36 (p=0.02) levels were lower in group 2 than in the other groups before and after the meal. After adjustment for body mass index, only the lower PYY3-36 level of group 2 remained statistically different from the other groups (p=0.01). CONCLUSION: Our study suggests that lower levels of PYY 3-36 are associated with binge eating in obese women.

OBJETIVO: O objetivo deste estudo foi avaliar, antes e após a refeição, as concentrações séricas de hormônios ligados ao controle do apetite (peptídeo YY3-36, grelina total, leptina e insulina) em mulheres obesas com e sem episódios de compulsão alimentar e compará-las às mulheres de peso normal. MÉTODOS: Vinte e cinco mulheres com idade entre 32 e 50 anos foram convidadas a participar deste estudo, incluindo 9 mulheres com peso normal (20-25kg/m²) sem episódios de compulsão alimentar (grupo 1), 9 mulheres obesas (³30 kg/m²) com episódios de compulsão alimentar (grupo 2) e 7 mulheres obesas sem episódios de compulsão alimentar (grupo 3). Foram coletadas quatro amostras de sangue pós-prandiais a 60 minutos (1 hora antes), bem como 15, 45 e 90 minutos após uma refeição composta de 55 por cento de carboidratos, 15 por cento de proteínas e 30 por cento de lipídeos. RESULTADOS: O maior HOMA-IR foi observado no grupo 3 (M=2,5, DP=1,04) quando comparado ao grupo 1 (M=1,5, DP=0,53) e ao grupo 2 (M=1,8, DP=0,58), p=0,04. O índice de massa corporal (p<0,0001), a leptina (p<0,0001) e a insulina (p=0,01) foram maiores no grupo 3 antes e após a refeição. A grelina total (p=0,003) e o PYY3-36 (p=0,02) foram menores no grupo 2 antes e após a refeição. Após o ajuste do índice de massa corporal, apenas a baixa concentração de PYY3-36 no grupo 2 manteve-se estatisticamente diferente entre os grupos (p=0,01). CONCLUSÃO: Este estudo sugere que níveis baixos do PYY-3-36 estejam associados à compulsão alimentar em mulheres obesas.

Metabolic effects of an entero-omentectomy in mildly obese type 2 diabetes mellitus patients after three years

BACKGROUND: Various digestive tract procedures effectively improve metabolic syndrome, especially the control of type 2 diabetes mellitus. Very good metabolic results have been shown with vertical gastrectomy and entero-omentectomy; however, the metabolic effects of an isolated entero-omentectomy have not been previously studied. METHODS: Nine patients with type 2 diabetes mellitus and a body mass index ranging from 29 to 34.8 kg/m² underwent an entero-omentectomy procedure that consisted of an enterectomy of the middle jejunum and exeresis of the major part of the omentum performed through a mini-laparotomy. Glucagon-like peptide-1 and peptide YY were measured preoperatively and three months following the operation. Fasting and postprandial variations in glycemia, insulinemia, triglyceridemia, hemoglobin A1c, and body mass index were determined in the preoperative period and 3, 18 and, 36 months after the operation. RESULTS: All patients significantly improved the control of their type 2 diabetes mellitus. Postprandial secretion of peptide YY and Glucagon-like peptide-1 were enhanced, whereas hemoglobin A1c, fasting and postprandial glucose, insulin, and triglyceride levels were significantly reduced. Mean body mass index was reduced from 31.1 to 27.3 kg/m². No major surgical or nutritional complications occurred. CONCLUSIONS: Entero-omentectomy is easy and safe to perform. A simple reduction in jejunal extension and visceral fat causes important improvements in the metabolic profile.

The serum level of peptide YY in rats with ulcerative colitis and its receptors' characteristics / 西安交通大学学报(医学版)

Objective To observe the changes of peptide YY (PYY) and its receptors in rats with ulcerative colitis (UC) by detecting both the serum level of PYY and jejunum epithelial cells in UC rats. Methods Rats were randomly divided into UC group, diarrhea-irritable bowel syndrome (D-IBS) group and control group. We measured the serum level of PYY by radioimmunoassay and made radioligand analysis of two basic parameters reflecting the characteristics of PYY receptors: dissociation constant (Kd) and maximum binding capacity (Bmax). Results The serum level of PYY was higher in UC and D-IBS groups than in normal group (P<0.001), and it was higher in UC group than in D-IBS group (P<0.001). However, the values of Kd and Bmax in UC group did not differ significantly from those in D-IBS and normal groups (P>0.05). Conclusion The serum level of PYY in UC group was significantly higher than that in normal group and D-IBS group; therefore, we assume that the change of serum PYY level may be related to not only the symptom of diarrhea but also inflammation. Kd and Bmax in neither UC group nor D-IBS group were significantly different from those in normal group, which indicates that the symptom and inflammation in UC may have nothing to do with the changes of PYY receptors.

The P-pouch: a New Ileal Reservoir Used in Restorative Proctocolectomy

PURPOSE: To evaluate the effectiveness of a P-pouch configuration with a reservoir and recycled segment in restorative proctocolectomy. METHODS: There were 11 patients who underwent the P-pouch procedure. They were compared with healthy eight-control subjects. The P-pouch configuration was constructed using one firing of a 10 cm GIA stapler to form a 12-cm reservoir. Following that, the distal ileum (15+/-0.5 cm) was anastomosed to the proximal portion of the pouch. Pouch function was studied 23.3+/-4.4 months after ileostomy closure. We measured the frequency and amount of stool. The postprandial plasma peptide YY (PYY) response and the scintigraphic studies using 99m-Tc sulfur colloid were used to study transit. RESULTS: In the patient group, daily stool frequency and volume were 5.2+/-0.3 and 423.5+/-23.7 g, respectively. Stool seepage and pouchitis occurred in 45.5 % and 9.1%. In contrast to other pouch procedures, the postprandial increment of plasma PYY was similar the P-pouch patients and healthy controls (P>0.05). The integrated increment of plasma PYY for 180 minutes following meals was also not decreased in 9-pouch patient group compared with the healthy controls (1,050.0+/-127.8 pmol/l vs. 1146.0+/-150.0 pmol/l, P>0.05). Small intestinal transit time for healthy controls and the patient group averaged 89+/-21 and 117+/-12 minutes (P>0.05). The capacity of the ileal pouch was 372+/-22 ml, and the efficiency of ileal reservoir evacuation was 76 %. CONCLUSIONS: The P-pouch is a new and improved simple modification of the well-established J-pouch procedure, constructed using a single firing of a GIA stapler.

Regional Distribution of Peptide YY Concentrations in Human Lower Gastrointestinal Mucosa

PURPOSE: Peptide YY is composed of 36 amino acids, and its functions are suppression of gastric acid secretion, delay of gastric emptying, increase of intestinal motility, inhibition of pancreatic exocrine secretion, and enhanced postprandial colonic absorption of water and electrolyte. PYY is released from PYY cells, which are mainly distributed in the ileum and colon, in response to the presence of intraluminal lipids. This study was designed to determine the regional distribution of PYY in the normal human ileum, colon, rectum, and anal canal by studying mucosal concentrations. METHODS: Fresh tissues were obtained from specimens of segmental resections of the small bowel, colectomies, ileostomies, and abdominoperineal resections for the management of colonic or rectal carcinomas or benign diseases of the bowel. Only specimens devoid of advanced luminal obstruction were included. Mucosa was separately recruited by microdissection of frozen sections. Radioimmunoassays were performed using the methods of Adrian et al. RESULTS: The concentration of PYY was highest at 25 cm proximal to the ileocecal valve in the ileum (307.6 pmol/ g) and in the upper rectum at the colon (653.1 pmol/g). The concentration of PYY was 27.3 pmol/g in the anal canal distal to the dentate line. A clear differential distribution of PYY was shown in the ileum and colon. CONCLUSIONS: This study showed PYY was present in large amounts in the mucosa of the ileum and colon, with high concentrations in locations 25 cm proximal to ileocecal valve and in the upper rectum, respectively. The trend of regional differences in PYY in the colonic mucosa probably reflects local differences in functions, such as absorption and storage. Also, the peak concentration in the ileum at 25 cm proximal to ileocecel valve suggests that this region is the most abundant production site of PYY in the ileum.

Sleeve gastrectomy model in DIO rat:establishment and evaluation / 中国普通外科杂志

Objective To investigate the weight loss mechanism of sleeve gastrectomy.Methods SD rats were fed with high-fat diet to induce obesity,and then the obesity rats were randomly divided into experimental group(underwent SG) and control group(underwent sham surgery).Eight weeks after operation,the body weight,food intake and peripheral blood concentration of Ghrelin,GLP-1,PYY3-36 of rats were checked.Results Compared with controll group,in experimental SG model,food intake was decreased(P 0.05).Conclusions The weight loss of sleeve gastrectomy in DIO rats's decline is lasting and obvious.The postoperative effect of decreased Ghrelin and increased GLP-1,PYY3-36 is the main mechanism for weight loss.

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.