Insulin response to secretogogues in sheep exposed to cold.

1. The effects of cold exposure on insulin secretion in response to intravenous injections of glucose, butyrate, arginine, glucagon and tolbutamide were examined in ten sheep exposed to a temperature of 0 degree C for 4-13 days. 2. Cold exposure produced a marked decrease in insulin responses to glucose and butyrate to a level similar to that caused by arginine administration. Cold exposure brought about a significant but only slight decrease in the insulin response to arginine. 3. Glucagon injection resulted in a markedly lower secretion of insulin in the cold than in the warm environment. 4. In the warm environment tolbutamide caused a significant increase in insulin secretion, but in the cold environment did not produce any statistically significant increase in plasma insulin. 5. It is concluded that cold exposure decreases insulin secretion in response to a variety of stimuli.