Abstract
The lower response to epinephrine and other catecholamines of epididymal adipose tissue from mice genetically obese and/or hyperglycemic could not be corrected by anti-insulin antiserum. This suggests that the lower response to catecholamines of these tissues does not result from the higher circulating insulin level in these mice. Inhibition of cyclic AMP phosphodiesterase by theophylline likewise did not enhance the response to epinephrine. Insulin inhibited the theophylline- and epinephrine-stimulated lipolysis of lethal yellow mice (Ay / a). No effect of insulin on theophylline-stimulated lipolysis of obese mice (ob/ob), diabetic mice (db/db) and viable yellow mice (Avy/a) and epinephrine-stimulated lipolysis of Avy/a mice was observed. The response of glucose metabolism in these mice to insulin was respectively the same as their lipolytic response, leading to the conclusion that their insulin resistance is not glucose specific.