Effects of a diazoxide inhibition of insulin release on food intake of normal and hyperphagic hypothalamic rats.

In order to clarify the role of endogenous insulin in generating normal and pathological feeding behaviors, the effect of an anti-insulin drug, Diazoxide, on the meal pattern has been investigated in both normal and VMH rats. A dose-dependent reduction of food intake under Diazoxide treatment was found in normal rats. The same percentage reduction was obtained at night with a higher dose than required in the daytime. Conversely, hyperphagic VMH rats exhibited a dose-dependent reduction which was identical in the two portions of the diurnal cycle. The dose effective in entirely suppressing eating in VMH rats was twice that required for normal rats in the daytime period and identical at night. The results are discussed in relation to earlier findings concerning the diurnal insulino-secretory pattern in normal and VMH rats.