Decreased hindlimb skeletal muscle weight and nuclear T 3 receptor binding of obese (ob/ob) mice

Abstract

Hindlimb muscle weights and binding of L-triiodothyronine (T 3) to isolated nuclei of hindlimb skeletal muscle were investigated in obese (ob/ob) and lean mice. At 12 weeks of age, although weighing substantially more, obese mice had only 55% as much muscle mass as their lean littermates. There was no phenotype effect observed for the equilibrium dissociation constant (Kd). However the apparent binding capacity (Bmax) was significantly less (P<0.001) for obese mice as compared to lean, thus confirming the preliminary results of Khan, et al. (7) which showed a trend for lower T 3 receptor concentration in skeletal muscle nuclei of obese mice.