BIOLOGICAL-ACTIVITY IN THE REPOPULATING RAT SPERMATOCYTE AFTER THE WITHDRAWAL OF GOSSYPOL TREATMENT .5. INHIBITION AND RECOVERY OF MICROTUBULAR DYNEIN

After oral administration with gossypol acetic acid for various rimes, young male rats developed a low content of microtubular (or cytoplasm ic) dynein in the spermatogenic cells, e.g., spermatids and primary sp ermatocytes. The content of dynein in the cells was measured by enzyme -linked immunosorbent assay (ELISA) using monoclonal anti-dynein antib ody. The results were expressed as ng dynein/10(6) cells and compared with those of the control rats. After gossypol treatment for 8, 12, an d 19 weeks, the content of dynein in spermatids was reduced by 61%, 70 %, and 68%, respectively; whereas, the amount of dynein in primary spe rmatocytes was reduced by 37%, 44%, and 31%, respectively. The microtu bular dynein associated with spermatids was more vulnerable to gossypo l than that of the primary spermatocytes. Immunofluorescent staining t echnique confirmed the finding that the control cells have more dynein than that of the drug-treated cells. Eight weeks after the withdrawal of the drug treatment, the content of dynein in spermatids and primar y spermatocytes was fully recovered. The possible effects of this chan ge in conjunction with the function of microtubules during spermatogen esis and sperm motility are discussed.