Regulation of oxygen consumption in perfused rat liver: decrease by alpha-sympathetic nerve stimulation and increase by the alpha-agonist phenylephrine.
In livers perfused with Krebs-Henseleit bicarbonate buffer containing bovine red cells, 5 mM glucose and 2 mM lactate, electrical stimulation round the hepatic artery and the portal vein caused via alpha-receptors a decrease in oxygen consumption and portal flow, an increase in glucose output and a switch from lactate uptake to output. In livers perfused with erythrocyte- and substrate-free buffer both in a volume- or pressure-constant system stimulation of the liver nerves resulted in similar changes. Infusion of the alpha-agonist phenylephrine mimicked the metabolic and hemodynamic nerve effects, but led to an increase in oxygen uptake. The converse effects of alpha-sympathetic nerve stimulation and alpha-agonist infusion on oxygen consumption indicate either a different mode of action or a complex mechanism with opposing metabolic and hemodynamic components.
D000818:Animals; D004558:Electric Stimulation; D005947:Glucose / Q000378:metabolism; D006439:Hemodynamics / Q000187:drug effects; D066298:In Vitro Techniques; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008099:Liver / Q000187:drug effects / Q000294:innervation / Q000378:metabolism*; D008297:Male; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology; D010101:Oxygen Consumption / Q000187:drug effects*; D010656:Phenylephrine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013564:Sympathetic Nervous System / Q000502:physiology
D007773:Lactates; D010656:Phenylephrine; D019344:Lactic Acid; D005947:Glucose