Age Effects on Lactic- and Malic-Acid Dehydrogenases in C57BL/6 Mouse Testes

Author Institution: Department of Biological Sciences, Kent State University, Kent, Ohio 44240There is evidence that lactic-acid-dehydrogenase (LDH) and malic-acid-dehydrogenase (MDH) activities vary with age in several mammalian organs. This study shows that both enzymes in the testes of the C57BL/6 mouse exhibit age-related changes. These changes are most evident when the LDH/MDH ratio is considered. The LDH/MDH ratio decreases to two days before onset of spermatogenesis, remains unchanged to one day before weaning, increases to four or five days prior to breeding activity, and oscillates through the remainder of the 365 days studied. Although these are in vitro results, activity changes occur coincident with physiological changes in the testes