PLASMA PEPTIDE YY AND PANCREATIC-POLYPEPTIDE IN DOGS AFTER LONG-TERM ADAPTATION TO DIETARY FATS OF DIFFERENT DEGREES OF SATURATION - OLIVE AND SUNFLOWER OIL

Mongrel dogs from weaning to 6 months of age were fed on one of two di ets that differed only in the type of fat content (virgin olive oil or sunflower seed oil) to compare plasma levels of peptide YY (PYY) and pancreatic polypeptide (PP) in the basal period and in response to foo d. Under resting conditions, blood concentrations of both peptides, me asured by specific radioimmunoassays, were significantly higher in the olive oil group. Food intake was not followed by any marked or signif icant changes in PYY or PP circulating levels, although some rises wer e observed. On the other hand, plasma PYY reached significantly greate r values throughout the postprandial period in the dogs fed on the die t containing olive oil, whereas no differences were recorded between t he groups as far as PP is concerned. Our results demonstrate that long -term intake of diets enriched in monounsaturated fatty acids (olive o il) produces significantly higher basal levels of PYY and PP, as well as significantly higher PYY levels in response to food compared with d iets containing sunflower oil. The differences, traceable to the compo sition of the two types of dietary fat supplied, explain the attenuate d pancreatic secretory activity observed by us previously in this anim al species. This mechanism may be responsible, at least in part, for t he adaptation of pancreatic secretion to the quality of dietary fat. ( C) Elsevier Science Inc. 1997.