Testicular histology in toad (Bufo melanostictus) following prolonged heat exposure.

A quantitative study of changes in the seminiferous tubule and the measurement of Leydig cell area were performed in the testis of toads exposed to 48 degrees C for 8 days. The frequency of occurrence of stages I and II was not affected whereas stages III and IV were influenced by the exposure to heat. The number of primary spermatocytes and secondary spermatocytes in stages III and IV were significantly decreased. The spermatocytes in stages III and IV were injured in the exposed toads. The area of Leydig cells including their nuclei was also decreased in the testes of heat exposed toads. It is concluded that the exposure to high temperature may have arrested spermatogenesis and affected Leydig cell function.