The effects of light deprivation/blindness on testicular function of gerbil (Meriones hurrianae Jerdon)

Abstract

1. Light deprivation either by enucleation or darkness resulted in a wide-spread testicular damage. The changes consisted of loss of type A spermatogonia, spermatocytes, spermatids and spermatozoa. 2. The atrophic testes of eyeless gerbils regenerated after 20 weeks and were indistinguishable from those of untreated, continuous light exposed animals. The reversible effects were not seen in continuous dark exposure. 3. Light deprivation (enucleation/continuous darkness) inhibits the synthesis of RNA, protein and sialic acid in the testes, epididymides and seminal vesicles. The testicular cholesterol and alkaline phosphatase activity was increased. 4. Haemoglobulin, haematrocrit and serum-transaminase levels were all the time within normal limits. Histological preparations of the liver showed normal architecture. 5. Reduced androgen production following a long term light deprivation was reflected in low levels of RNA and sialic acid in the testes and epididymides and shrunken Leydig cell nuclei. 6. In conclusion, light deprivation caused damage to the male genital tract of gerbils.