Neuropeptide Y effects on vasorelaxation and intestinal contraction in the Atlantic cod Gadus morhua.
Neuropeptide Y (NPY) has prominent cardiovascular effects in mammals and sharks, but no such effect has previously been demonstrated in any teleost fish. In the Atlantic cod, we found that cod NPY (10(-10)-10(-6) M) relaxed celiac arteries precontracted with epinephrine, and weak contractions were elicited in intestinal ring preparations. A few NPY-immunoreactive nerve fibers were present along small gut arteries. The results suggest that cod NPY produces vasorelaxation both by a direct action on smooth muscle and by release of prostaglandins, but with no involvement of nitric oxide, leukotrienes, or endothelium-derived relaxing factors. An additional indirect effect involving another neurotransmitter may occur. Cod NPY (10(-7) M) and human NPY (10(-7) M) had identical effects on the vessels. Small differences only in the effects of porcine [Leu(31),Pro(34)]NPY, NPY-(13-36), and cod NPY suggest the presence of a Y(1) subfamily receptor, similar to the zebrafish Ya receptor. A physiological role for NPY in teleost vasculature is concluded, but surprisingly the effect, a vasodilation, is opposite to that in mammals and is mediated by prostaglandins.
Shahbazi
Fatemeh
F
Department of Zoophysiology, Göteborg University, SE-405 30 Göteborg, Sweden. Fatemeh.Shahbazi@zool.gu.se
Holmgren
Susanne
S
Larhammar
Dan
D
Jensen
Jörgen
J
D000818:Animals; D002445:Celiac Artery / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D005260:Female; D005399:Fishes / Q000502:physiology*; D005769:Gastrointestinal Motility; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007422:Intestines / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009412:Nerve Fibers / Q000378:metabolism; D009478:Neuropeptide Y / Q000494:pharmacology*; D017476:Receptors, Neuropeptide Y / Q000378:metabolism; D013552:Swine; D014664:Vasodilation; D014666:Vasomotor System / Q000187:drug effects*
D009478:Neuropeptide Y; D017476:Receptors, Neuropeptide Y