Coronary Arteriosclerosis in Sclerosed Rabbits: -With Special Reference to the Effect of Clinofibrate-@@@―クリノフィブラートの効果―

Subjects were a total of 24 mature male Japanese white rabbits averaging 38 months of age comprising a healthy normal group of 8 rabbits, a sclerotic group of 9 rabbits, and a therapeutic group of 7 rabbits. For the latter 2 groups, arteriosclerosis was experimentally prepared by combining inhalation of N2 gas, i. p. injection of noradrenalin, and oral administration of cholesterol (0.5g/day). The therapeutic group was also given Clinofibrate (200mg/day) simultaneously with the start of the above loading. 22 weeks later, all rabbits were sacrificed and the tissue was cut off from a proximal region of the left coronary anterior descending branch. The tissue was then embedded in parafin after 10%-formalin fixation, sliced to a thickness of 4μ by a JB4A Automicrotome, and specially stained for each of 5 arterioarchitectural components: smooth muscle cell (SMC); elastin (EL); collagen (CL); glycosaminoglycans (GAGs); and PAS positive material. The tissue was observed and determined histochemically by microspectrophotometer (MSP). The above coronary components for the sclerotic group showed a significant decrease in SMC and an increase in EL, CL, GAGs, and PAS positive material as compared with the healthy normal group. Compared with the sclerotic group, pathological hyperplasia of SMC and various other connective tissues in the clinofibrate group were inhibited. Overall estimation of the contents of these 5 components by principal-component analysis also revealed approximate characteristics of the therapeutic group to the healthy normal group, suggesting an inhibitory effect of clinofibrate on the progress of coronary arteriosclerosis.