不同剂量X线照射对大鼠卵巢功能的影响

Effects of different X-ray doses on the ovarian function of rats

目的探讨不同剂量X线照射对大鼠卵巢功能的影响。方法将60只Wistar大鼠随机分为对照组、G0.1组、G1.0组、G10.0组,分别采用0、0.1、1.0、10.0 Gy X线外照射,于照射后1 h、5 d(1个动情周期)、10 d(2个动情周期),分别应用免疫组化SABC法、免疫放射法检测不同剂量X线照射不同时间后Wistar大鼠在不同动物周期中卵巢颗粒细胞Bcl-2蛋白的表达水平及生殖激素雌二醇(E2)、卵泡刺激素(FSH)、黄体生成素(LH)的水平;并比较各组上述指标。结果 X线照射后1 h,各组各级卵泡数目及各激素水平比较,P均>0.05。X线照射后5d,与对照组比较,G0.1组各级卵泡数目升高,血清FSH降低、LH及E2升高;G1.0、G10.0组各级卵泡数目减少,血清FSH升高、LH及E2降低(P均<0.05);X线照射后10 d,G10.0组各级卵泡数目减少,血清FSH升高、LH及E2降低(P均<0.05)。与其余组比较,G10.0组X线照射5、10 d各级卵泡数目减少,血清FSH升高,LH及E2降低(P均<0.05)。与同组内照射后1 h比较,照射后5 d,G0.1组各级卵泡数目升高,血清FSH降低、LH及E2升高(P均<0.05),照射后10 d,均恢复至正常水平;G1.0组照射后5 d各级卵泡数目降低,血清FSH升高、LH及E2降低(P均<0.05),照射后10 d恢复至正常水平;G10.0组照射后5、10 d各级卵泡数目均降低,血清FSH升高、LH及E2降低(P均<0.05)。与照射后1 h比较,G0.1组照射后5 d Bcl-2阳性表达率升高,G1.0组照射后5 d降低,G10.0组照射后5、10 d均降低(P均<0.05)。结论低剂量X线照射可一定程度抑制细胞凋亡,避免卵巢损伤;当照射剂量超过一定值(≥1.0 Gy),卵巢功能受损,但损伤是可逆的;当给予超大剂量(10.0 Gy)照射后,卵巢功能严重损伤,甚至出现不可逆性早衰。

Objective To observe the effects of different X-ray doses on the ovarian function of rats. Methods Sixty Wistar rats were randomly divided into four groups ： the control group,G0. 1 group,G1. 0 group and G10. 0 group,with different X-ray doses（ 0,0. 1,1. 0,and 10. 0 Gy）. At 1 h,5 d（ an estrous cycle）,10 d（ two estrous cycles） after exposure,the expression levels of the Bcl-2 protein,the E2,FSH,and LH in the ovarian granulosa cells of Wistar rats in different animal cycles after different X-ray doses were observed by immunohistochemistry and immunoradiometry,and then we compared the above indicators. Results At 1 h after X-ray radiation,no significant difference was found in the number of follicles and the level of each hormone between groups（ all P 〉0. 05）. At 5 d after X-ray radiation,the number of follicles increased,the serum FSH decreased and the levels of LH and E2 increased in the G0. 1 group as compared with those of the control group; the number of follicles decreased,the serum FSH increased and the levels of LH and E2 decreased in the G1. 0 and G10. 0 groups（ all P 〈0. 05）. At 10 d after X-ray radiation,the number of follicles at all levels decreased,serum FSH increased,and LH and E2 decreased in the G10. 0 group（ all P 〈0. 05）. Compared with the other groups,the number of follicles decreased,FSH increased,and LH and E2 decreased in the G10. 0 group at 5 and 10 d after X-ray radiation（ all P 〈0. 05）. At 5 d after X-ray radiation,the number of follicles increased,the serum FSH decreased,and LH and E2 increased in the G0. 1 group as compared with that at 1 h（ all P〈 0. 05）,and they all returned to the normal levels at 10 d（ P〈 0. 05）; at 5 d after X-ray radiation,the number of follicles decreased,the serum FSH increased,and LH and E2 decreased in the G1. 0 group as compared with that at 1 h（ all P〈 0. 05）,and they all returned to the normal levels at10 d（ P 〈0. 05）; at 5 and 10 d after X-ray radiation,the number of follicles decreased,the serum FSH increased,and LH and E2 decreased in the G10. 0 group（ all P〈 0. 05）. The positive rate of Bcl-2 in the G0. 1 group increased at 5 d after X-ray radiation,decreased in the G1. 0 group at 5 d after X-ray radiation,and decreased in the G10. 0 group at 5 and10 d after X-ray radiation（ all P 〈0. 05）. Conclusions Low-dose X-ray radiation can inhibit the apoptosis to a certain extent,and avoid the ovarian injury. When the radiation dose exceeds a certain value（ greater than 1. 0 Gy）,the ovarian function is impaired,but the damage is reversible. When the oversize dose（ 10. 0 Gy） is given,the ovarian function is severely damaged,even with irreversible premature aging.