Stimulation of protein biosynthesis in round spermatids from rat testes by lactate

lactate (20 mM) was found to increase protein synthesis of round spermatics (steps 1-8) from rat testes to a much greater extent than glucose (10 mM). Stimulatory effect of lactate on protein synthesis was also observed to some degree in spermatocytes and late spermatids (step 13-16), but not in Leydig cells and 7 day-old testis cell suspensions. In addition, lactate enhanced the intracellular level of ATP in round spermatids. The response of protein synthesis in round spermatids was closely related to the intracellular level of ATP. The results suggest that among various types of testicular cells the round spermatids may be the most responsible for the lactate-induced stimulation of protein synthesis which is largely regulated by the ATP.