Effect of dietary vitamin C on radiation induced damage to the testis

We have investigated the ability of dietary vitamin C (ascorbic acid) to mitigate radiation induced damage to the testis arising from exposure to x-rays or the Auger emitting radionuclide 114mIn (half-life 50 days). Male mice were maintained on a normal or an ascorbate enriched diet (1% by weight) for 5 days then irradiated with 3 Gy 300 kVp x-rays or injected intraperitoneally with 114mIn (1.85-14.8 MBq kg-1). Diets were continued for the duration of the experiment. At 35 days post-irradiation animals were killed and testicular damage was assessed using testis weight and spermhead counts as biological endpoints. Acute irradiation with 3 Gy x-rays resulted in severe damage to the seminiferous epithelium manifested as a 50% reduction in testis weight and more than 80% reduction in spermhead count, no differences were observed between control and ascorbate treated animals. Similarly chronic irradiation by tissue-incorporated 114mIn caused a dose-dependent reduction in testis weight and spermhead count and no abrogation of this effect was observed with ascorbate. While the enriched diet did result in elevated testicular ascorbate levels this effect was short-lived and appeared to be subject to diurnal variation. These results suggest that vitamin C does not have a role as a radioprotectant in the testis against medical or environmental radiation exposures.