Radiation effects on testes. Pt. 15

Effects of gamma-irradiation have been studied on NADP and NADP linked dehydrogenases of tests of rats after 720 and 2000 R surface exposures. After 720 R, activity of MDH (per mg protein and per 100 mg testes) declined between day 1 and 6 followed by a tendency of recovery from day 7 to 37. After a dose of 2000 R, minimum activity of MDH was observed on day 9; subsequently, it regenerated and became above normal value on days 25 and 33. Although the diphasic pattern of ME was similar to that of MDH at 2000 R, ME continued to decrease after 720 R over a period of 37 days. In contrast to MDH and ME, NADH2 diaphorase regenerated at faster rate after a transient loss during the first week. The synchrony observed between MDH and ME at 2000 R and association of hyperplasia of interstitial cells suggested that the pyruvate carboxylase pathway involving transhydrogenation plays an important role in lipogenesis of atrophied testes. Activity of LDH in whole testes was not influenced after 2000 R up to day 33, whereas it showed a significant increase on day 37 after 720 R. However, the analysis of different parts of testes suggested a significant loss of LDH in seminiferous tubulus and a stimulation in interstitial cells on day 30 after 720 R. Loss of LDH in seminiferous tubulus and loss of SDH in whole testes was an indication towards the loss of more matured germ cells of testes following irradiation. (orig.)