DIFFERENT EFFECTS OF CONTINUOUS NIGHT AND DAYTIME INSULIN INFUSION ON THE MEAL PATTERN OF NORMAL RATS - COMPARISON WITH THE MEAL PATTERN OF HYPERPHAGIC HYPOTHALAMIC RATS

The different night and day-time effects of continuous intravenous infusion of various doses of insulin on the meal pattern have been investigated in normal rats. In the day-time a dose-response curve was apparent. An 86-220% increase in the 12 hr cumulative intake was due to an increase in the number of meals for the lowest dose and in both the size and number of meals for the highest doses. With the same doses given at night the average increase in 12 hr intake was limited to 27% and was not dose-dependent. The changes in the various features of the meal pattern, observed under the effects of continuous insulin infusion, resembled those observed after VMH lesions. The similarities between these effects can be considered to support the assumption of the role played by hyperinsulinism in hypothalamic hyperphagia. © 1979.