Vasoactive Intestinal Peptide and Anterior Pituitary Function

Abstract

Vasoactive intestinal peptide (VIP) is a highly basic 28 amino‐acid peptide which was first isolated from porcine small intestine (Said & Mutt, 1970). It is related to several other peptides including PHI (peptide with N‐terminal histidine and C‐terminal isoleucine amide), secretin, glucagon, and has some sequences similar to those of growth hormone releasing hormone (Fig. 1). The amino‐acid sequence of human VIP is identical with that of the porcine form (Itoh et al., 1983). It has been shown that human VIP is cosynthesized with PHM (peptide with N‐terminal histidine and C‐terminal methionine amide, the human analogue of PHI) from the same large precursor protein (Itoh et al., 1983).