A comparison of circadian rhythms in feeding, plasma insulin, glucose and glucagon between normal and diabetic Chinese hamsters.

Twenty-four hour feeding patterns were determined for diabetic and normal Chinese hamsters. Plasma insulin, glucose and glucagon were determined for those time periods that corresponded to the high and low points of food intake and for 3 time periods during which the animals ate an intermediate quantity of food. There was no difference in the feeding pattern between groups though the diabetics consumed more food during a 24-h period. Plasma glucose, insulin and glucagon reached a peak during the nocturnal phase of feeding in the nondiabetic group. On the other hand, plasma glucose remained elevated over the entire time period in the diabetic group. Also, plasma insulin reached a peak during the daylight in the diabetics. There was no difference between groups in plasma glucagon.