Lactate-glucose interrelations, glucose recycling and the Cori cycle in normal fed rats.
1. Turnover and oxidation rates of glucose and lactate were determined using a priming dose-continuous infusion of 14C-(u)-glucose and 14C-(U)-lactate in anesthetized and mechanically ventilated non-fasted rats. The rates of glucose-lactate interconversions were computed from the two-compartment model of Depocas and De Freitas (1970). The rate of total glucose recycling is known as the difference between the rate of true glucose turnover measured with 3H-(2)-glucose (RGT) and the rate of apparent glucose turnover measured with 14C-glucose (RG). This value was compared with the Cori cycle. 2. In normal conditions 17% of RG come from lactate, 43% are directed to lactate and 49% are oxidized. 3. 71% of the rate of lactate turnover come from glucose, 28% are directed to glucose and 51% are oxidized. 4. The rate of total glucose recycling (RGT-RG) is 3.7 mg - mn(-1) per kg0.75 and represents 60% of RG or 38% of RGT. 5. The Cori cycle is 0.8 - 1.2 mg - mn(-1) per kg0.75 and represents 8 - 20% of the rate of glucose turnover and 20 - 32% of total glucose recycling.
D000818:Animals; D002250:Carbon Radioisotopes; D004435:Eating; D005947:Glucose / Q000096:biosynthesis* / Q000378:metabolism; D007773:Lactates / Q000378:metabolism*; D008297:Male; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D051381:Rats; D014316:Tritium
D002250:Carbon Radioisotopes; D007773:Lactates; D014316:Tritium; D005947:Glucose