AMINO-ACID-METABOLISM IN THE KIDNEYS OF GENETIC AND NUTRITIONALLY OBESE RATS

The ability of the kidney to take up and/or release amino acids has be en determined in two models of obesity in Zucker rats, one genetic and the other nutritional (diet-obese). There was a noticeable increase i n gluconeogenic amino acids in the arterial blood of diet-obese animal s whereas the genetically obese rats showed small variations in the le vels of these amino acids. There were significant decreases in renal G ly and Ser, only in the genetically obese rats. Genetically obese anim als showed an increase in Glutamine synthetase activity. The uptake an d/or release of amino acids showed important Variations between the gr oups. The diet-obese group exhibited greater variation, since this gro up took up Glu, Ala, Gy, Phe and Citrulline and released Gin, Ser, Arg and Tyr. Genetically obese rats took up Gin, His and Taurine and rele ased Ser. These different patterns may be related to variations in the whole body metabolic rate, since the diet-obese group was more active than the genetically obese group.