低剂量X射线照射选择性诱导小鼠睾丸生精细胞凋亡的适应性反应

目的 研究低剂量X射线照射诱导小鼠睾丸生精细胞凋亡的适应性反应。方法 昆明雄性小鼠接受诱导剂量(D1，75mGy)和攻击剂量(D2，1．0，2．0和3．0Gy)全身照射。通过不连续泛影葡胺密度梯度离心法分离小鼠睾丸组织不同种类生精细胞，流式细胞术(FCM)检测各类生精细胞凋亡。结果 当D2照射前6h给予D1预照射时明显减轻D2对睾丸精原细胞和精母细胞凋亡的损伤作用，而对精子细胞和精子影响不明显。当D1和D2间隔3，6，12和24h，发现D2剂量较小(1．0和2．0Gy)时，精原细胞和精母细胞的凋亡百分率减少出现较早、较明显，而且持续时间较长；反之，D2剂量较大(3．0Gy)时，精原细胞和精母细胞凋亡百分率变化不明显。结论 低剂量X射线照射可以选择性诱导小鼠睾丸精原细胞和精母细胞凋亡的适应性反应，并与D1和D2间隔时间及D2剂量有关。

Adaptive response of spermatogenic cell apoptosis selectively induced by low dos e X-ray irradiation in mice

Objective The adaptive response of spermatogenic cell apoptosis induced by whole-body X- r ay irradiation at low doses was studied in mice. Methods Kunming m ale mi ce were irradiated with an inductive dose (D1:75 mGy) and/or a challenging dose (D2:1 0,2^0 or 3 0 Gy).Different kinds of spermatogenic cells were separated using d ensity gradient centrifugation and their apoptotic percentages were analysed usi ng flow cytomentry (FCM). Results When the mice were irradiated w ith D1 6 h before irradiation with D2,the apoptotic percentages of the spermatog onia and spermatocytes declined rapidly as compared with those in the groups irr adiated with D2 only,and those of spermatids and spermatozoa showed no significa nt ch anges.When the interval times between D1 and D2 was 3,6,12 or 24 h,the apoptotic percentages in spermatogonia and spermatocytes reduced early,significantly and continued for a longer duration after smaller D2(1^0 and 2^0 Gy) irradiation,w hile the apoptotic percentages did not change after larger D2(3^0 Gy) irradiati on. Conclusion The adaptive response of apoptosis in spermatogonia and spermatocytes could be selectively induced by low dose X-ray irradiation.Th e adaptive response could be closely related to the D2 dose and interval time be tween D1 and D2.;