abstract
- In order to study the role of elastin in arteries with respect to hypertension and hypertensive arterial disease, aortic elastin content and elastase-like enzyme activity were examined and compared in stroke-prone spontaneously hypertensive rats (SHRSP), which show malignant hypertension, and Wistar-Kyoto normotensive rats (WKY). The elastin content was lower, whereas the elastase-like activity was higher at 20 weeks of age in SHRSP than in WKY, so that the aortic elastin/enzyme ratio of SHRSP was lower than that in WKY. These differences were not found at 6 weeks of age (prehypertensive stage). For SHRSP anti-hypertensive treatment resulted in lowering the elastase-like activity and in increasing the elastin content in comparison to untreated animals. The subcellular distribution of the elastase-like activity closely correlated with that of 5'-nucleotidase activity, a plasma membrane marker enzyme. The results indicate involvement of a smooth muscle plasmalemmal elastase-like enzyme in vascular connective tissue metabolism in health and possibly also its participation in hypertensive arterial diseases.