Demonstration of perivascular peptides and changes in concentration with age in man

By immunocytochemistry, human cerebral arteries have been found to be invested by perivascular fibres which contain neuropeptide Y, substance P and vasoactive intestinal polypeptide (VIP). The concentrations of the peptides are comparable for substance P and VIP, whereas that of neuropeptide Y is much higher. A marked reduction in radioimmunoassayable peptide levels was observed with advancing age of the patients.