Acetylcholinesterase and cholinesterase activities, protein content and wet weight measures in the rat brain after early hypophysectomy

Abstract

The development of acetylcholinesterase (AChE) and cholinesterase (ChE) activities, weight measures and protein content were determined for specific brain samples from early hypophysectomized and control female rats at 33–35 days of age. Of the eight brain samples, only two, the somatosensory and ventral cortex, showed significantly less AChE activity in the experimental compared to the control rats. The decrease in the somatosensory AChE activity was postulated to reflect a developmental deficit of sensory-motor function due to the dwarfing of the body mass and surface. The decrease in the ventral cortical sample was interpreted as due to alterations in the development of behavioral and hormonal limbic mechanisms. Early hypophysectomy reduced the level of ChE activity in only one brain region, the hypothalamus. This decrease was thought to be due primarily to alterations in the function of the supraoptic and paraventricular nuclei whose neurosecretory products are normally released from the neurohypophysis. The protein content was not significantly different between the cortical samples from the hypophysectomized and control rats.