EXPRESSION AND CHARACTERIZATION OF PREPROVIP DERIVED PEPTIDES IN THE HUMAN MALE UROGENITAL TRACT

Expression of the gene sequence encoding vasoactive intestinal polypep tide (VIP) leads to the synthesis of a 170 amino acid precursor molecu le which can be processed to five fragments: preproVIP 22-79, peptide histidine methionine (PHM), or peptide histidine valine (PHV), preproV IP 111-122, VIP and preproVIP 156-170. Using region specific radioimmu noassays and antisera against the functional domains of the VIP precur sor in combination with immunocytochemistry and chromatography, the lo calization, distribution and identity of the preproVIP derived peptide s within the human male urogenital tract were investigated. Postmortem as well as fresh tissue specimens were used. All the preproVIP derive d peptides were expressed and could be demonstrated in nerve fibres th roughout the urogenital tract in close relation to the epithelial lini ng and in vascular as well as non-vascular smooth muscle. The VIP-rela ted peptide containing fibres were most abundant in the prostate paren chyma and the seminal vesicle. Using double immunostaining, co-localiz ation of the various preproVIP derived peptides could be evidenced. Th e fact that all preproVIP derived peptides are present in the urogenit al tract, should be taken into consideration when the regulatory aspec ts of neuropeptides in physiological and pathophysiological functions are discussed.