Neuropeptide Y effects on vasorelaxation and intestinal contraction in the Atlantic cod Gadus morhua

Abstract

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.

Sympathetic, parasympathetic and enteric regulation of the gastrointestinal vasculature in rainbow trout (Oncorhynchus mykiss) under normal and postprandial conditions

“…The signal is subsequently sent to the submucosal vasculature, via nitrergic perivascular nerves releasing vasoactive factors such as, nitric oxide (NO) (Jennings et al, 2004), endothelial-dependent prostaglandins (Kagstrom and Holmgren, 1997), neuropeptide Y (Shahbazi et al, 2002) and vasoactive intestinal polypetide (Jensen et al, 1991;Kagstrom and Holmgren, 1997). In mammals there is also a muscarinic-receptor-mediated release of endothelial NO (Vanner et al, 1993).…”

“…In mammals there is also a muscarinic-receptor-mediated release of endothelial NO (Vanner et al, 1993). However, given that it is still debatable whether or not NO is synthesized and released only from nerves in fish or if there is also an endothelial subform (Olson and Donald, 2009;Olson and Villa, 1991), prostaglandins could function as an endothelially derived vasorelaxing factor in fish, comparable to that of NO in mammals (Jennings et al, 2004;Shahbazi et al, 2002).…”

Characterization of neuropeptide Y in snakeskin gourami and the change in its expression due to feeding status and melanocortin 4 receptor expression

“…For example, the expression of TpNPY mRNA in the intestine and stomach suggests that NPY functions as a brain-gut peptide. In addition, the vasodilatory effect of NPY was elucidated in the cod gut [43]. The substantial expression of TpNPY in the testes and ovaries suggests a role of NPY in the reproductive Fig.…”

Evolutionary perspective on the NPY-PYY-PP peptides and their receptors

“…Both NPY and PYY contracted isolated gut arteries in three species of elasmobranchs [121]. In eel, NPY enhanced the contractile force of the isolated atrium [122,123]. In contrast, NPY produced vasorelaxation of celiac arteries of the Atlantic cod, Gadus morhua [123].…”

“…In eel, NPY enhanced the contractile force of the isolated atrium [122,123]. In contrast, NPY produced vasorelaxation of celiac arteries of the Atlantic cod, Gadus morhua [123]. Thus, the most common effect of NPY on blood vessels is contraction, as in mammals.…”