Some effects of vasectomy on the reproductive system of the ram

Perera, Buthgamu Mudiyanselage Amithral Oswin (1975) Some effects of vasectomy on the reproductive system of the ram. PhD thesis, University of Glasgow.

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The purpose of this study was to examine, the response of the male reproductive system of rams to the altered physiological status existing after vasectomy. Vasectomised rams were examined at different periods up to three years and nine months after the operation, with regard to the structure and functional state of their testes, epididymides, vasa deferentia, vesicular glands, prostate gland and bulbo-urethral glands. The ejaculate was studied for the presence, morphology and metabolic activity of spermatozoa, and the seminal plasma for its fructose concentration. The levels of androgens in the peripheral blood were determined by a radioimmunoassay. Intact rams were studied by similar methods in order to establish the normal status of reproductive function and the seasonal variations occurring in this species. The changes occurring in the testis after vasectomy were restricted to the seminiferous tubules, where spermatogenic activity was found to be both qualitatively and quantitatively affected. The interstitial (Leydig) cells were found to be functionally unchanged, as demonstrated by the similarity of androgen profiles in intact and vasectomised rams during the breeding and the non-breeding seasons. The epididymal changes were most marked in the region of the cauda epididymidis, where enlargement, multiple spermatocoeles and sometimes rupture of the serous covering were observed in vasectomised animals. Although evidence of increased sperm removal by phagocytosis was found, the epididymis was unable to cope successfully with excurrent duct blockage even when the testis was producing smaller numbers of spermatozoa than normal. Evidence was also obtained indicating interference with sperm maturation in the epididymis of some vasectomised rams. The ejaculates of vasectomised rams contained immotile spermatozoa fox well over one year after the operation. Although these spermatozoa were found to be structurally intact for up to three to six months, they were neither fertile nor metabolically active after two to four weeks in most cases. The storage site from which these spermatozoa are voided at ejaculation was located as being the glandular acini surrounding the lumen of the ampulla. The secretory activity of the glandular epithelium in the ampulla and vesicular gland was altered in some vasectomised animals, and this was reflected in the histological appearance of the cells and in the fructose concentration of the ejaculate. These animals had either increased or decreased secretory activity when compared with intact rams, although their androgen profiles were not significantly different from those of intact rams.

Item Type: Thesis (PhD)
Qualification Level: Doctoral
Additional Information: Adviser: P G Hignett
Keywords: Animal sciences
Date of Award: 1975
Depositing User: Enlighten Team
Unique ID: glathesis:1975-73709
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 14 Jun 2019 08:56
Last Modified: 14 Jun 2019 08:56

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