The Effect of Age and Hypophysectomy on Growth and the lsoenzymes of Lactate Dehydrogenase in the Mouse Testis

Abstract

Testis weight of the mouse increases linearly with time, but seminal vesicle weight shows a rapid increase in size after 24 days of age. The testis-specific isoenzyme of lactate dehydrogenase (LDH-X) appears between 12-14 days postpartum which corresponds to the appearance of the first wave of pachytene primary spermatocytes. Hypophysectomy in the mature mouse causes a decrease in both testis and seminal vesicle weight and a linear decrease in LDH-X activity in the mouse testis. Considering the available evidence for the control of LDH-X synthesis in the mouse, it seems reasonable to conclude that FSH and the testosterone produced by LH action on the Leydig cells, are both required for the induction and maintenance of LDH-X synthesis in the mouse testis.