Muscle atrophy by limb immobilization is not caused by insulin resistance

Hindlimbs of adult female rats were immobilized for 1 day. The hindquarter was then perfused either without or with 200 microunits of insulin/ml perfusate. The percentage increase in muscle protein synthesis rates by the inclusion of insulin in the perfusate was similar between control and hindlimb immobilized groups. Thus, the previously reported inability of insulin to stimulate any increase in glucose metabolism in skeletal muscle after 1 day of immobilization ( Seider , Nicholson and Booth 1982) does not also extend to an inability of insulin to stimulate an increase in protein synthesis in muscles of immobilized limbs.