HEPATIC DENERVATION ALTERS THE TRANSITION FROM THE FED TO THE FOOD-DEPRIVED STATE IN CONSCIOUS DOGS

The hepatic nerves can modulate hepatic glycogenolysis and glycogenesis and thus might be expected to be involved in the response of the animal to the transition from the fed to the food-deprived state. Therefore the arterial concentrations and net hepatic balance of glucose and its metabolites, as well as the hepatic glycogen concentrations, were compared in hepatic-innervated and -denervated dogs 18, 24 and 42 h after their usual daily meal. Arterial concentrations of glucose, alanine, lactate and glycerol; net hepatic balances of glucose, alanine and glycerol; and glycogen concentrations were similar in hepatic-innervated and -denervated dogs at each time investigated. Net hepatic balances of lactate (with negative values indicating uptake) in hepatic-innervated and -denervated dogs, respectively, were: 18 h, 4.1 +/- 4.3 vs. -4.3 +/- 3.6 mumol.kg-1.min-1; 24 h, 4.8 +/- 3.6 vs. -6.7 +/- 1.7 mumol-kg-1.min-1 (P < 0.05); 42 h, -7.0 +/- 2.0 vs. -6.8 +/- 1.0 mumol.kg-1.min-1. Based on changes in net hepatic lactate balance, the denervated liver responds more rapidly to food deprivation than the innervated liver, but the metabolic state of the liver appears similar by 42 h after a meal.