Plasma glucose and insulin response to glucagon and arginine in Aston ob/ob mice: evidence for a selective defect in glucose-mediated insulin release.

Fed adult obese hyperglycaemic (ob/ob) mice fail to produce a positive plasma insulin response to an intraperitoneal (ip) glucose challenge. The present study demonstrates that both fed and fasted ob/ob mice produce a marked positive plasma insulin response to an ip challenge by glucagon or arginine throughout the phases of development and regression of the ob/ob syndrome. These observations provide evidence that failure of the B-cells to respond to glucose in fed adult ob/ob mice cannot be attributed to inadequate amounts of releasable insulin. In addition, the results show that the B-cells of fed adult ob/ob mice do not incur a generalized defect of stimulus-recognition-secretion-coupling.