Influence of microinjection of insulin into the ventromedial hypothalamus on acetate metabolism in rumen epithelium of sheep.

Injections of 50 microU insulin into the ventromedial hypothalamic nuclei (VMH) in intact sheep decreased the rates of 14C transfer from 14C-1-acetate into CO2, glucose, ketone bodies, and increased the rates into triglyceride and phospholipids in rumen epithelium of sheep. Insulin injections into the parietal cortex of intact sheep or into the VMH of sheep with VMH lesions had no effect on the acetate metabolism in rumen epithelium as compared with the control groups which received saline injections into the same brain regions. These results support the view that the VMH serves as an integral part of an insulin-sensitive brain regulatory system in the acetate metabolism of rumen epithelium.