[Morphogenesis of central and peripheral arteriopathies in the hypertensive rat. 2. Histochemical aspects]

Twenty-seven enzyme activities and five macromolecular complexes in central and peripheral arteries of the spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) 4, 20, 30 and 60 week-old rats were comparatively studied. Some of the four-week-old SHR (prehypertensive stage) showed several enzyme-cytochemical differences in comparison with WKY of the same age. In the adult SHR (20 to 60 weeks), the metabolic behaviour of different arterial segments was not uniform. Thus, the arteriopathy of elastic-type arteries was reflected by early and permanent activation of 5' nucleotidase and by the early increase (between 5 and 30 weeks) and later decrease (60th week) of esterase-and cholinesterase-activity. Peripheral arteriopathy was evidenced by hyperactivity and/or hypoactivity of glycogen-synthetase, glycogen-phosphorylase and monamine oxidase (in muscular-type arteries) and by early (5th week) and long lasting (60th week) hyperactivity of alcaline phosphatase (in arterioles). Some parameters were modified throughout the whole vasculature: increase in RNA, glycosaminoglycans, and glycoproteins, heightened lysosomal and dehydrogenase enzyme activities. Certain reported chemical modifications are discussed in connection with atherogenesis (carboxylic esterases and glycosaminoglycans) and peripheral tensiogenesis (5' nucleotidase, alcaline phosphatase, L-amino-peptidase, MAO).