[The presence and distribution of insulin in rat brain and its relation to feeding]

Using the immunohistochemical method, insulin was proved to exist in cells of hypothalamus, thalamus, cerebral cortex, hippocampus, ependyma of third ventricle and choroid of rat, including some of the neuronal nuclei, and was further confirmed by immunoelectromicroscopy. The insulin concentrations in rat brain differed in various regions. Simultaneous determinations of insulin concentrations in brain, CSF and blood showed that the brain insulin could not originate from blood through CSF. The participation of brain insulin in regulating of body energy balance at hypothalamus was illustrated and discussed.