Role of peptide PYY in obesity

Abstract EN

ABSTRACT: Background: Peptide YY (PYY) is a 36 amino acid peptide secreted from ileal L cells following meals.

The cleaved subpeptide PYY (3-36) is biologically active and may constitute the majority of circulating PYY-like immune reactivity.

The peptide family that includes PYY, pancreatic peptide and neuropeptide Y is noted for its orexigenic effect following intracerebroventricular administration.

The gut hormone fragment peptide YY3-36 (PYY) reduces appetite and food intake when infused into subjects of normal weight.

While PPY 1-36 stimulates appetite, so PYY 3-36 and PYY 1-36 have opposing effects on food intake.

Peptide YY has been suggested to counteract ghrelin by inducing satiety and reducing appetite and caloric intake.

Objective To determine the plasma level of fasting PYY in obese and lean subjects and find the role of PYY in the pathogenesis of obesity.

Study Design The present study was conducted on 40 subjects aged 20-55 years, 13 males and 27 females.

Subjects were classified into 2 groups according to their body mass index.

Group 1: 20 healthy lean subjects with body mass index (BMI) between: 19.50-25 kg/m2.

Group II: 20 healthy obese subjects with body mass index (BMI) between: 25-42 kg/m2.

For all subjects full history taking, thorough clinical examination, including anthropometric measurements {body weight, height, calculation of body mass index (BMI)} estimation of fasting plasma levels of PYY and fasting ghrelin level.

Results: Fasting PYY levels were significantly lower in obese subjects (GrII) ( 54.3+1.09 pmol/L) than lean subjects (GrI) (57.83+ 4.02 pmol/L).

Fasting PYY levels were high in females (59.1 + 4.7 pmol/L) than males (55.9+1.3 pmol/L) in GrI.

Postprandial PYY (2 hrs after a mixed meal) decreased in GrII (51.65 + 2.03 pmol/L) and GrI ( 51.60 + 2.23 pmol/L)