Spermatogenesis degeneration

Urinary calculi are frequent concomitants of vitamin A deficiency. The epithelium of the urinary tract shares in the general pathological changes of all epithelial structures. Epithelial debris thus may provide the nidus around which a calculus is formed. Abnormalities of reproduction include impairment of spermatogenesis, degeneration of testes, abortion, resorption of fetuses, and production of malformed offspring. 

A subacute study in rats treated intraperitoneally with deltamethrin showed testicular degeneration and an inhibition of spermatogenesis, which seemed to be mediated by an elevation of nitric oxide levels [148], Subcutaneous dosing also produced adverse testicular effects and reduced spermatogenesis [149],... 

M (reduced spermatogenesis Kamalu 1993 cycle, germ cell sloughing NaCN and degeneration)... 

Testicular histopathology revealed that major early changes after exposure to 1,3-DNB consisted of degeneration of germinal epithelium and sloughing of both spermatocytes and spermatids which in turn resulted in reduced sperm counts and reduced sperm mobility (Blackburn et al. 1988 Evenson etal. 1989b Linder etal. 1988, 1990 Reader etal. 1991). Disrupted spermatogenesis was also evidenced by a decrease in the number of seminiferous tubules in rats treated with 48 mg/kg of... 

Deficiency symptoms Bitot s spots, xerosis, night blindness, keratomalacia, diarrhoea, follicular hyperkeratosis, papular eruptions, drying of epidermis, urinary calculi, degeneration of testis, impaired spermatogenesis, sterility, abortion, impairment of smell and taste. 

Endocrine and Reproductive Effects. Because the male and female reproductive organs are under complex neuroendocrine and hormonal control, any toxicant that alters any of these processes can affect the reproductive system (see Chapters 17 and 20). In addition metals can act directly on the sex organs. Cadmium is known to produce testicular injury after acute exposure, and lead accumulation in the testes is associated with testicular degeneration, inhibition of spermatogenesis, and Leydig-cell atrophy. 

A small number of studies have reported that male rats fed aflatoxins developed testicular degeneration and impaired spermatogenesis, although no clear association with aflatoxins and clinical infertility was uncovered in one of these studies. 

Oral administration of hexachlorophene to rats causes degeneration of spermatogenic cells. In sheep, 2500 mg kg followed 2 days later by a dose of 50 mg kg also caused extensive damage to spermatogonia after 21 days there was neither sperm in epididymis nor spermatogenesis. 

Reproductive Effects. The effects of nitrobenzene on reproduction have not been studied in humans by inhalation, oral or dermal routes of exposure. In rats, inhalation of nitrobenzene has resulted in testicular degeneration and decreased sperm levels (Dodd et al. 1987 Hamm 1984). Cessation of spermatogenesis, followed by a slow and incomplete recovery, was observed in rats following a single oral dose of nitrobenzene (Levin et al. 1988). These findings suggest that reproductive effects may also be an area of concern for men exposed to nitrobenzene in occupational settings. 

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