흰쥐 정관절제수술후 생식세포의 변화

Abstract

The effect of vasectomy on the gonadal cells was studied in adult rats. Particular attention was paid to the endocrine function of the organ, and the total content of Leydig cells was quantitati-velly estimated. 36 rats were divided into two groups, control and vasectomized. Bilateral vasectomy was performed in one group of 18 rats, and the other group of 18 rats was kept sham operation under sodium pentobarbital anesthesia. A single paramediam incision was made in the abdomen and about 0.5cm in length of vas deferens was removed on 1 cm from caudal portion of epididymis. three animals were sacrificed on the day of 3, 7, 14, 28, 56 and 112 days after operation in both groups respectively. Testis, epididymis and seminal vesicle was removed. After removal, each testis was carefully weighed and its volume was determined by use of Kotharis principle (volume=weight in air-weight in water). Testis, epididymis and seminal vesicle were fixed in Bouin's solution and paraffin specimens were prepared in usual method, sectioned at 5μm thickness, and stained with hematoxylin-eosin. The total Leydig cell volume was estimated by the histometric pointcounting method, and could be calculated in absolute terms, that is, milliliters per testis. The rusults are summerized as follows: Vasectomy produced a degeneration of the seminiferous tubules as well as some reduction in the testicular volume, and revealed more marked changes in prolonged to time of operation. At the 8th weeks after vasectomy, spermatogenesis ceased completely, but the basal cells or spermatogonia remained unaffected, which could be explained how spermatogenesis might occur again under favourable circumstances after vasorrhaphy. There was no fibrosis, cellular infiltration or necrosis. No evidence of regeneration was found up to eight weeks after vasectomy. The Leydig cells became relatively increased in number after vasectomy. Quantitatively, they increased from 1. 58±0.43 ml to 1.87±0.70 ml per testis, a modest but definite average increase of about 20 per cent. The histologic pictures, however, gave a more exaggerated impression because of the simulataneous collapse and degeneration of the tubules. There was marked dilatation of lumen and thickening of basement membrane of the epididymal tubules after vasectomy. These changes were all suggestive of increased pressure in the epididymal tube behind the obstructed vas deferens. There was no particular changes after vasectomy in the seminal vesicle. These changes suggest the impotence following vasectomy is, at least, not attributed to vasectomy itself.