Substance P-containing nerve fibres in large peripheral blood vessels of the rat.
Substance P-immunoreactive nerve fibres were localized by the indirect immunohistochemical method in the adventitia and the adventitial-medial border of large peripheral arteries and veins of the rat. Arteries showed a richer substance P-containing innervation than veins. The superior mesenteric artery was densely innervated, whereas no substance P-containing fibres were found around the carotid artery. Substance P produced a vasoconstriction of the veins, but was basically without effect on arteries, although with the carotid artery a dose-dependent relaxation was observed. The absence of a correlation between the degree of innervation of the blood vessels and their responsiveness to exogenous substance P suggests that there nerves do not subserve a vasomotor function. The depletion of substance P immunoreactivity from nerves in arteries and veins by capsaicin suggest that substance P-containing vascular nerves are primarily sensory in nature.
D000818:Animals; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009121:Muscle Denervation; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009412:Nerve Fibers / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000378:metabolism* / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D013373:Substance P