EFFECTS OF DIETARY SELENIUM ON DIFFERENTIATION, MORPHOLOGY AND FUNCTIONS OF SPERMATOZOA OF THE HOUSE RAT, RATTUS-RATTUS L

Ingestion of 2 ppm and 4 ppm selenium in the diet by the house rat, Ra ttus rattus, for 5 weeks caused a dose-dependent reduction in its body weight, testicular and cauda epididymidis weights, concentration, mot ility and percentage of live spermatozoa with a simultaneous increase in the percentage of their abnormal forms. Compared to 1.39% abnormal spermatozoa in cauda epididymidis in untreated control rats, 3.89% and 24.64% abnormal spermatozoa were observed in rats with 2 ppm and 4 pp m dietary selenium respectively. Ingestion of 4 ppm selenium had no si gnificant effect on abnormalities of the head and neck regions but abn ormalities of the midpiece region and multiple abnormalities increased significantly. Analysis of the various stages of differentiation of s permatids in the testis has revealed that with 4 ppm dietary selenium, the abnormalities are induced mainly in the midpiece region of the fl agellum which is a site of energy production.