Lipolytic and adenyl-cyclase-st imulat ing activity of ?~-trinitrophenyl glucagon: comparison with other glucagon

It has recently been reported from one of our laboratories that the Nc~-tr ini trophenyI (TNP) derivat ive of glucagon stimulates hepatic g lycogenolys is w i th an in t r ins ic ac t i v i t y comparable to that of glucagon. This compound, however, has negligible abil i ty to stimulate ! lver adeny! cyciase ( i ) . The derivative is also a competit ive antagonist of the action of glucagon on liver adenyl cyclase. In this report we present the effects of this and other NH 2 terminal analogs on the Iipolytic and adenyl cyclase activit ies of the rat adipocyte. All analogs stimulate adenyl cyclase in the adipocyte. Except for the TNP der iva t ive , these analogs have greater l ipolytic than glycogenolytic activity. The TNP derivative did not inhibit the l ipolytic act iv i ty of glucagon.