METABOLIC INTER-ORGAN RELATIONS BY EXERCISE OF FED RAT - CARBOHYDRATES, KETONE-BODY, AND NITROGEN-COMPOUNDS IN SPLANCHNIC VESSELS

Fed rats were exercised until exhaustion by almost 65% VO2max On a tre admill. In 2.5 min after the exercise, blood was collected from variou s vessels of the splanchnic bed. Metabolites, glucose, lactate, ketone body, and nitrogencompounds in the plasma, were measured. Glucose exc retion from the liver was increased by exercise, but was not significa nt. The absorption by the kidney decreased to 30% by exercise. Lactate was highly absorbed by the kidney, lower limbs, and digestive tract b y exercise. Exercise caused a 200-300% increase of the plasma beta-hyd roxybutyrate, but the absorption by the kidney and the lower limbs was decreased. These data suggest that glucose is a good carbon source fo r the recovery, and that lactate is more useful than glucose, but keto ne body is less effective at a very early recovery phase under fed con dition. Amino acid balances in each organ except digestive tract were positive showing anabolic conditions of these organs even after exhaus tive exercise at fed condition. Most amino acid concentrations in the plasma tended to decrease to 60-90% by exercise. Amino acids were excr eted from the digestive tract, and were eventually absorbed by the liv er in both rested and exercised rat. The digestive tract, therefore, s eems to be a primary amino acids pool to supply them to the liver duri ng the inter meal. Urea excretion from the liver was more than the abs orbed ammonia showing that active deamination from amino acids was car rying on. The resulted carbon skeletons of the amino acids might be us ed for the gluconeogenesis in the liver.