Glucagon secretory responses to insulin-induced hypoglycemia and arginine in streptozotocin-induced diabetic dogs.
To clarify whether the reactivity of A cells is regulated by B cell function in the pancreas, plasma glucagon (IRG) responses to insulin-induced hypoglycemia and to arginine infusion were evaluated in streptozotocin (STZ; total 40 mg/kg) treated and control dogs. There was no significant rise in plasma IRG levels during the insulin-induced hypoglycemia in the STZ-treated dogs. In contrast, arginine enhanced the IRG secretion from the pancreas to a similar extent in the two groups. This was deduced from the difference between IRG levels in the pancreaticoduodenal and peripheral veins. Neither intravenous glucose nor arginine infusion resulted in a significant rise in plasma insulin (IRI) levels in the STZ-treated dogs. IRI content in the pancreas of STZ-treated dogs was significantly reduced to 5 percent below the levels in the control dogs. The IRG content for control and STZ-treated dogs did not differ. These results indicate that while the responsiveness of A cells to hypoglycemia may depend on the secretory capacity of B cells, such is not the case with arginine.
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D002450:Cell Communication; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D004285:Dogs; D005260:Female; D005934:Glucagon / Q000378:metabolism*; D007003:Hypoglycemia / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism / Q000494:pharmacology*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000378:metabolism; D008297:Male
D007328:Insulin; D005934:Glucagon; D001120:Arginine