Possible Interaction: Epinephrine and Neuropeptide Y

“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.”

“In addition, the contractile responses to NA (and adrenaline ) were enhanced in the presence of NPY.”

“ NPY greatly enhanced the adrenergically mediate contractile response to electrical stimulation and to application of adrenaline , noradrenaline or histamine, as studied in the isolated rabbit gastro-epiploic and femoral arteries.”

“Our data show that NPY can directly regulate human adrenal cortisol production.”

“Recently, it was reported that porcine NPY was an inhibitor of in vitro human platelet aggregation induced by epinephrine , an observation which would have important implications regarding platelet-vascular interactions during states involving platelet activation and thrombosis.”

“Inhibition of NPY or Y1 signaling, either transgenically or pharmacologically, prevented the attenuation of both TH expression and epinephrine release.”

“Plasma epinephrine was decreased by NPY in fed chicks, but plasma concentrations of norepinephrine and epinephrine were increased significantly by NPY in fasted-heat exposed chicks.”

“These results indicate that, under basal conditions, adrenal signaling is tonically inhibited by NPY , but stress overrides this autocrine negative feedback loop.”

“ EPI markedly up-regulated the expression NPY and the Y1R at the commitment stage, followed by increased Y2R mRNA at the late of the commitment stage and the differentiation stage.”

“These results … that NPY can increase the sensitivity of the α2-… belonging to hypothalamic NA and/or to adrenaline nerve terminals and to cortical NA nerve terminals, while the α2-heteroreceptors inhibiting3H-HT release in the same brain regions appear not to be regulated by high affinity NPY receptors.”