Browsing by Author "Sumana Chakravarty"

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Antispermatogenic and antifertility effects of 20,25-diazacholesterol dihydrochloride in mice
(2003) Shio K. Singh; Sumana Chakravarty
The effect of intraperitoneal administration for 28 days of 10, 20, and 30 mg/kg body weight per day of 20,25-diazacholesterol dihydrochloride (SC 12937), a hypocholesterolemic agent, on the testis of Parkes (P) strain mice was investigated. Histologically, testes in mice treated with 10 or 20 mg/kg body weight of SC 12937 showed non-uniform degenerative changes in the seminiferous tubules as both affected and normal tubules were observed in the same section; the affected tubules showed intraepithelial vacuolation, occurrence of giant cells, exfoliation of germ cells, and marginal condensation of chromatin in round spermatids. In both dosage groups, only 11-12% of the seminiferous tubules were affected, and no significant differences were found in the frequency of affected tubules between the two groups. By contrast, testes in mice treated with 30 mg/kg body weight of the drug exhibited a degenerated appearance of germ cells in all seminiferous tubules. The treatment also had adverse effects on motility, viability, morphology, and number of spermatozoa in the cauda epididymidis, and on fertility. Even 56 days after drug withdrawal, the above parameters remained markedly affected. Our results thus suggest that SC 12937 treatment causes antispermatogenic and antifertility effects in P mice and that the effects are not reversible up to 56 days after drug withdrawal. This compound may prove useful in the control of rodent populations. © 2002 Elsevier Science Inc. All rights reserved.
Effect of 17 α-cyanomethyl-17 β-hydroxy-estra-4,9-dien-3-one on reproductive organs of the male laboratory mouse
(1998) Sumana Chakravarty; Shio Kumar Singh
The effect of subcutaneous administration (10, 15 and 20 mg/kg body weight/day, for 21days; and 20 mg/kg body weight/day, for 28 days) of 17α -cyanomethyl-17β-hydroxy- estra-4, 9-dien-3-one (STS 557) on the male reproductive organs of the Parkes strain mouse was investigated.The effect of the treatment on the testis was not uniform; both regressed and normal seminiferous tubules were observed in the same section of the organ. Furthermore, the histological changes observed in the seminiferous tubules in testes of STS 557 - treated mice were not different in different dosage groups. In general, in moderately affected seminiferous tubules, the germinal epithelium was thin and consisted of Sertoli cells, spermatogonia, spermatocytes and spermatids; such tubules showed presence of many vacuoles in the epithelium. In severe cases, the tubules had collapsed and were lined by mainly Sertoli cells, spermatogonia and spermatocytes. The treatment also caused marked depression in motility and concentration of spermatozoa in cauda epididymidis, weight of accessory sex glands and in the levels of sialic acid and fructose in the epididymis and seminal vesicle ,respectively. By 56 days of drug withdrawal, the alterations induced in the reproductive organs returned to control levels, suggesting that STS 557 treatment induces reversible alterations in the male reproductive organs of Parkes strain mouse.
Histologic changes in the mouse testis after bilateral vasectomy
(2000) Shio Kumar Singh; Sumana Chakravarty
Aim: To study the effect of vasectomy on histological appearance of the testis. Methods: Parkes strain mice were used as the animal model; they were bilaterally vasectomized (Vx) or sham-operated (So) and killed at intervals of 4, 6, 9, and 12 months after the operation. Testes were excised from 5 Vx and 5 So mice at each interval and processed for histological examination. Results: Testes of So mice showed normal histological features. By contrast, marked alterations were observed in the seminiferous tubules in testes of Vx mice, except in those killed 4 months after the operation. The seminiferous epithelium in the tubules was only 2-3 layers thick and showed much depletion of germ cells; in severe cases, the epithelium consisted of only a thin layer of Sertoli cells, spermatogonia and a few spermatocytes. Exfoliation of germ cells, occurrence of multinucleated giant cells and vacuolated appearance of the epithelium were of common features in the tubules. Furthermore, lumen of the rete testis in Vx mice was greatly dilated and showed accumulation of spermatozoa with immature germ cells; in mice vasectomized for 6-12 months, several macrophages ingesting spermatozoa were often observed in the lumen of the rete testis. Spermatic granuloma was also sometimes noticed in corpus or in cauda regions of the epididymis in mice vasectomized for 6-12 months. Conclusion: We suggest that consequences of vasectomy should be thoroughly understood in order to make this method rather more popular as a reversible method of male contraception. © 2000, Asian Journal of Andrology.