Since Baló and Banga found that elastase had an action of degrading elastin, many reports on the relationships between arteriosclerosis and elastase were published. Hall found that elastase had two component, one is elastoproteinase, which shows protein digesting activity, and the other, elastomucase which has lipolytic activity.
Previous study showed that elastase had an antiarterisoclerotic action in rat induced fed with atherogenic diet and vitamin D2 for four days orally. The mechanism of antiarteriosclerotic action of elastase were assumed to be a regulating action of biosynthesis of elastin in the arterial wall.
In this paper, the results on regression of arteriosclerosis in rats were presented.
Fourty arteriosclerotic rats experimentally induced fed with atherogenic diet together with 4 days vitamin D2 at weeks 7 were divided into 4 groups; (1) Group R-N fed with standard diet. (2) Group R-NE fed with standard diet and treated with elastase (I. M. 450 El.U/kg/day). (3) Group R-A fed with atherogenic diet continuously. (4) Group R-AE fed with atherogenic diet and treated with elastase continuously.
At 12 and 15 weeks during the experiment, the changes in aortic elastic fibers were determined in these four groups of rats. There were little changes between Group R-N and R-NE at week 12, but when compared with the Group R-N and R-NE at week 15 respectively, the latter group showed less fissure of elastic fibers. In sharp contrast to the Group R-A, Group R-AE revealed much less marked interstitial rarefaction and fissure of elastic fibers at 12 as well as 15 weeks, which suggests that elastase and standard diet could bring about an action of regressing experimental arteriosclerosis of rats induced fed with atherogenic diet and 4 days vitamin D2.
