EXISTENCE AND COEXISTENCE OF VASOACTIVE SUBSTANCES IN NERVE-FIBERS SUPPLYING THE ABDOMINOPELVIC ARTERIAL TREE OF THE FEMALE PIG AND COW

The occurrence and co-localization of several presumed vasoactive neur opeptides, serotonin, and catecholamine-synthesising enzymes - tyrosin e hydroxylase (TH), dopamine-beta-hydroxylase (D beta H) and phenyleth anolamine-N-methyltransferase (PNMT) - were investigated in perivascul ar nerves supplying the systemic and distributing arteries of the abdo mino-pelvic arterial tree of the female pig and certain arteries suppl ying female reproductive organs in the cow. As revealed by single immu nofluorescence, perivascular axons immunoreactive for TH, D beta H, ne uropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), substance P (SP), calcitonin gene-related peptide (CGRP) and Leu(5)-enkephalin (LENK) occurred in both species examined, whereas galanin-immunoreacti ve (GAL-IR) nerve fibres were found exclusively in the pig. PNMT-, ser otonin-, dynorphin A-, alpha-neoendorphin-, bombesin- or cholecystokin in-IR nerve terminals were not observed. The following classes of peri vascular nerve fibres might be distinguished in the present study: 1) noradrenergic (i.e. TH/D beta H-IR), 2) NPY-, 3) GAL (pig only), 4) LE NK-, 5) VIP-, 6) SP-, 7) VIP/NPY, 8) SP/CGRP-, 9) SP/GAL, (pig only), 10) SP/VIP- (cow only), 11) TH/D beta H/NPY- and 12) TH/D beta H/NPY/L ENK-IR. Distinct differences in the distribution of LENK- and SP-IR ax ons around particular parts of the studied arterial tree in individual species were also observed. The present data indicate that the abdomi no-pelvic arterial tree of the pig and cow receive perivascular nerve fibres that exhibit diverse chemical codes, and that different chemica l coding of perivascular nerve fibres in individual species may depend on the target organ of the particular artery.