INFLUENCE OF MEAL COMPOSITION ON POSTPRANDIAL PERIPHERAL PLASMA-CONCENTRATIONS OF VASOACTIVE PEPTIDES IN MAN

In a randomized cross-over study healthy non-obese male human subjects received standardized isocaloric, isovolumetric meals consisting of e ither carbohydrate, protein or fat and a non-caloric control meal cons isting of an equal volume of water. Peripheral venous plasma concentra tions of calcitonin gene-related peptide (CGRP), substance P (SP), vas oactive intestinal peptide (VIP), and peptide YY (PW) were measured pr e- and postprandially. Plasma CGRP concentrations were lowered followi ng the protein meal and following the fat meal, but remained unaltered after carbohydrate or water ingestion. Plasma VIP concentrations incr eased slightly following the carbohydrate meal and following water loa ding. The PW concentrations increased after the protein and the carboh ydrate meal and a slight rise was observed following fat ingestion. Wa ter loading did not affect the plasma level of PW. We conclude that th e postprandial peripheral plasma concentrations of CGRP, VIP and PW ar e dependent on the caloric meal composition. The VIP, but not the CGRP and PW concentrations seem to be influenced by gastric distension. Th e physiological significance of the postprandial alterations in periph eral concentrations of these peptides is at present uncertain.