Effect of Peptide Tyrosine Tyrosine (PYY3-36) on High Fat Diet Induced Obesity and its Metabolic Hazards in Adult Albino Rats

Aim of work: The role of pancreatic polypeptide family including Neuropeptide Y (NPY), and Peptide Tyrosine Tyrosine (PYY) in obesity development and its metabolic changes is controversial due to multiple receptor involvement. Therefore, this study was designed to investigate the effect of a potent Y2 receptor agonist; Peptide Tyrosine Tyrosine (PYY3-36) on high fat diet (HFD) induced obesity in adult albino rats of both sexes. Materials and Methods: forty two adult albino rats were divided into 6 equal groups: Controlmale (kept on standard diet), HFD male, HFD male +PYY treated, Control female (kept on standard diet), HFD female and HFD female + PYY treated groups. PYY3-36 was administered (50μg\ kg) by intraperitoneal injection twice daily during the 5th week of high fat diet protocol to rats of the treated groups. Blood samples were collected for measurement of lipid profile, glucose and leptin. Body weight, lee index and daily food intake were also measured. The brain was removed and the hypothalamus was isolated for determination of NPY concentration. Peritoneal omental fat was removed as the whole gastrocolicomentum fat (GCOF) and weighed. Results: Consumption of HFD resulted in a significant increase in food intake in the first and second weeks then decreased significantly at the end of the study in the HFD groups as compared with control groups. This was accompanied with a significantly higher body weight, lee index, serum glucose, leptin levels and weight of (GCOF) with a significant decrease in hypothalamic NPY concentration. These were associated with a state of dyslipidemia. Peripheral administration of PYY 3-36 with HFD decreased food intake, body weight, lee index, GCOF weight, hypothalamic NPY, plasma leptin and glucose. In conclusion, PYY3-36; the potent Y2 receptor agonist could prevent partially HFD induced obesity. Gender differences revealed that males developed higher measures of obesity with more adverse metabolic effects.