不同剂量电离辐射所致Leydig细胞对hCG反应性的变化

Studies on the effects of different doses of X-irradiation on the response of Leydig cells to hCG

本文报告了不同剂量X线所致Leydig细胞对hCG反应性的变化。幼年雄性大鼠睾丸的Leydig细胞经预培养24小时后,分别接受25,50,75,100,250mGy小剂量的X线照射(剂量率为12.5mGy/分)以及0.5,1.0,2.0,4.0,8.0Gy大剂量X线照射(剂量率0.51Gy/分)。然后加入浓度为0.025或0.05i.u./ml的hCG,继续培养48小时,观察Leydig细胞对hCG反应性的变化。结果表明,小剂量辐射在25,50mGy组引起Leydig细胞对0.05i.u./ml hCG的反应性增高,而在各小剂量组对0.025i.u./ml hCG的反应性无明显变化。大剂量辐射Leydig细胞在各剂量组对0.025和0.05i.u/ml hCG的反应性均降低,此种降低有照射剂量依赖性。对上述变化的可能机制进行了讨论。

The present paper reports the effects of low and high doses of X-irradiation on hCG-induced testosterone secretion in cultured rat Leydig cells. The Leydig cells harvested from testis in immature rats were exposed to 25, 50, 75, 100, 250 mGy and 0.5, 1.0, 2.0, 4.0, 8.0 Gy X-irradiation at a dose-rate of 12.5 mGy/min and 0.51 Gy/min respectively after a preincubation for 24h. The cells were stimulated with 0.025 or 0.05 i.u./ml of hCG for 48 h in culture after X-irradiation. In low dose irradiated Leydig cells, the response to 0.05 i.u./ml of hCG in both 25 and 50 mGy groups was significantly higher than that of the control. No significant changes were found in response to 0.025 i.u./ml hCG in all the low dose groups. In high dose irradiated Leydig cells, the response to either 0,025 or 0.05 i.u./ml hCG was significantly inhibited in a dose-dependent manner. It is concluded that low dose ionizing irradiation acts synergistically with hCG in stimulation of testosterone production, while higher doses inhibit its secretion. The possible mechanisms of these effects were discussed.