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 treadmill. In 2.5 min after the exercise, blood was collected from various vessels of the splanchnic bed. Metabolites, glucose, lactate, ketone body, and nitrogencompounds in the plasma, were measured. Glucose excretion from the liver was increased by exercise, but was not significant. The absorption by the kidney decreased to 30% by exercise. Lactate was highly absorbed by the kidney, lower limbs, and digestive tract by exercise. Exercise caused a 200-300% increase of the plasma beta-hydroxybutyrate, but the absorption by the kidney and the lower limbs was decreased. These data suggest that glucose is a good carbon source for the recovery, and that lactate is more useful than glucose, but ketone body is less effective at a very early recovery phase under fed condition. Amino acid balances in each organ except digestive tract were positive showing anabolic conditions of these organs even after exhaustive exercise at fed condition. Most amino acid concentrations in the plasma tended to decrease to 60-90% by exercise. Amino acids were excreted from the digestive tract, and were eventually absorbed by the liver in both rested and exercised rat. The digestive tract, therefore, seems to be a primary amino acids pool to supply them to the liver during the inter meal. Urea excretion from the liver was more than the absorbed ammonia showing that active deamination from amino acids was carrying on. The resulted carbon skeletons of the amino acids might be used for the gluconeogenesis in the liver.
Hirai
T
T
Faculty of Health and Sport Sciences, Osaka University, Machikaneyama, Japan.
Minatogawa
Y
Y
Hassan
A M
AM
Kido
R
R
D000596:Amino Acids / Q000097:blood*; D000641:Ammonia / Q000378:metabolism; D000818:Animals; D001158:Arteries / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism*; D007657:Ketone Bodies / Q000097:blood*; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D008297:Male; D005082:Physical Exertion; D051381:Rats; D017208:Rats, Wistar; D013152:Splanchnic Circulation / Q000502:physiology*; D014508:Urea / Q000378:metabolism; D014680:Veins / Q000378:metabolism
D000596:Amino Acids; D001786:Blood Glucose; D007657:Ketone Bodies; D007773:Lactates; D019344:Lactic Acid; D000641:Ammonia; D014508:Urea