Partial liver denervations dissociate the inhibitory effects of pancreatic glucagon and epinephrine on feeding.
We compared the roles of different components of the liver's innervation in the inhibitory effects of pancreatic glucagon and epinephrine on feeding by testing the effects on meal size of intraperitoneal injections of these hormones in rats with selective abdominal vagotomies of only the hepatic branch, with partial liver denervations that spared only the hepatic branch of the vagus, and with sham operations. Pancreatic glucagon (100-400 micrograms/kg) inhibited size of evaporated milk test meals equally in rats with partial liver denervations sparing the hepatic vagus and in sham-operated rats, but had no effect on feeding in rats with selective hepatic vagotomies. In contrast, epinephrine (25-100 micrograms/kg) inhibited meal size equally in all rats. These data suggest that the hepatic vagus is the necessary and sufficient contribution of the liver's innervation to pancreatic glucagon's satiety effect and that hepatic innervation does not contribute to epinephrine's inhibitory effect on meal size. Thus, different peripheral neural mechanisms appear to mediate the effects of these hormones on feeding. Further, the data fail to support the hypothesis that abdominal vagotomies and coeliac ganglionectomies attenuate epinephrine's effect on feeding by disconnecting hepatic afferents.
D000818:Animals; D003714:Denervation; D004837:Epinephrine / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects*; D005934:Glucagon / Q000494:pharmacology*; D008099:Liver / Q000294:innervation*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014628:Vagotomy
D005934:Glucagon; D004837:Epinephrine