Ultrastructural study of the choroid plexus of spontaneously hypertensive rats

We previously gave an account of an increased ion transport activity in choroid plexus from spontaneously hypertensive rats. We have since examined this organ in scanning and transmission electronic microscopy. In the choroid plexus from young spontaneously hypertensive rats, the epithelial cells showed the following: a partial loss of the brush border and infoldings of basolateral membranes, an increased number of Golgi apparatus, vesicles, and mitochondria, and an activated nucleus. In adult hypertensive rats, the mitochondria had increased in number and tended to fill the cytoplasma while the nuclei had returned to a resting level. These ultrastructural changes furthermore suggest an increased secretory activity in the choroid plexus in spontaneously hypertensive rats.