Semiquantitative histochemical investigation of lysosomal enzyme activities in the aortic endothelial cells of spontaneously hypertensive rats

In order to obtain information about changes in lysosomal enzyme activities in the aortic endothelial cells under hypertensive conditions, semiquantitative histochemical investigations of acid phosphatase (Ac-Pase) and N-acetyl-β-gluco-saminidase (NAGase) activities in the aorta of spontaneously hypertensive rats (SHR) were performed on 'Häutchen' monolayer preparations. The aortic endothelial cells in SHR showed increased Ac-Pase and NAGase activites as compared with those in control normotensive rats, and the activities tended to increase with advancing age. The degenerating process of endothelial cells expressed by lysosomal enzyme activity seems to be accelerated by hypertension. The increased lysosomal enzymes may participate in the further development of hypertensive vascular changes.