Effects of the Amount and Type of Dietary Fat on Exocrine Pancreatic Secretion in Dogs after Different Periods of Adaptation

Abstract

Mongrel dogs were fed, from weaning to 6 months of age, on one of two 9% lipid diets that differed only in the type of fat content (sunflower oil or virgin olive oil) to study their effects on exocrine pancreatic secretion, in the basal period and in response to food. In addition, the results were compared with those obtained in a previous work performed by us on dogs adapted for 8 months to diets containing a higher (15%) amount of the same dietary fats to further evaluate the influence of the amount of dietary fat and the length of the adaptation period. The results from the present study show that both the volume and bicarbonate secreted in the absence of stimuli are unaffected by the quality of dietary fat. In contrast, in response to food, the pancreatic juice flow and the bicarbonate output were significantly higher in the group of animals given the sunflower oil diet. The differences seem to be related with the oleic acid content in the diets and the effectiveness of this fatty acid in triggering the release of inhibitory peptides such as pancreatic polypeptide and peptide YY. The comparison between the results from our present and previous studies supports the afore-mentioned hypothesis and confirms the existence of a clear influence of the amount and type of dietary fat, especially the oleic acid content, upon the pancreatic response to food, without ruling out a role for the duration of the adaptation period.