[Effects of 3,5,3'-triiodothyroacetic acid (TRIAC) on protein metabolism of genetically obese or non-obese Zucker rats].

Genetically obese female rats (fa/fa) and their lean littermates (Fa/-) were given oral administration of 3,5,3-triiodothyroacetic acid (TRIAC) (20 micrograms/ 100 g of body weight/ day) during 4 weeks. Metabolism of proteins was evaluated in several organs and in skeletal muscle after intraperitoneal injection of 14C and 3H-leucine 6 days and 16 hrs respectively before the sacrifice of animals. We have determined radioactivity of 14C and 3H and the 3H/14C ratio. No significant differences were found in lean and obese rats except in skeletal muscle. The relative protein turnover in skeletal muscle is significantly higher in the obese rats than in the lean rats. Treatment by TRIAC decreases the body weight gain in obese rats compared with controls but it has no statistically significant effect on the relative protein turnover in either obese or lean rats.