Semiquantitative histochemical investigation of lysosomal enzyme activities in the aortic endothelial cells of rats with renal hypertension

To obtain information about changes in lysosomal enzyme activities in the aortic endothelial cells in arterial hypertension, semiquantitative histochemical investigations of acid phosphatase (Ac-Pase) and N-acetyl-β-glucosaminidase (NAGase) activities in the aorta of rats with renal hypertension were performed on "Häutchen" monolayer preparations. The aortic endothelial cells in renal hypertensive animals showed increased Ac-Pase and NAGase activities compared with those in control normotensive rats and tended to increase with advancing age. These results, like our previous data from spontaneously hypertensive rats (SHR), indicated that degeneration of endothelial cells, expressed by increased lysosomal enzyme activity, was accelerated by hypertension, and the possible participation of genetic factors in the activation of these enzymes in SHR was ruled out. Increased lysosomal enzyme activity may be involved in the development of other hypertensive vascular changes.