低剂量辐射诱导小鼠睾丸生精细胞凋亡的适应性反应

目的：研究低剂量辐射诱导小鼠睾丸生精细胞凋亡的适应性反应。方法：应用原位末端标记（TUNEL）和常规HE染色法分别结合光镜定量地观察75mGyX射线照射诱导小鼠睾丸生精细胞在生精周期中凋亡的适应性反应。结果：当1．0、2．0或3．0Gy（攻击剂量，D2）X射线照射前6h给予75mGy（诱导剂量，D1）预照射时明显减轻D2对睾丸精原细胞和精母细胞的凋亡损伤作用，而对精子细胞影响不明显，当1．0、1．5、2．0、2．5、3．0Gy（D2）X射线照射前3、6、12、24h给予75mGy（D1）预照射时，发现当D2剂量较小（1．0、1．5、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，当D2剂量较大（2．5和3．0Gy）时，精原细胞和精母细胞的凋亡百分率减少只有照后6h）出现，而且不显著。结论：低剂量电离辐射可以诱导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 induced by low dose X-ray irradiation in mice

Objective\ To study the adaptive response of spermatogenic cell apoptosis induced by whole\|body X\|ray irradiation with low doses in male Kunming mice. Methods\ The spermatogenic cell apoptosis induced by 75 mGy X\|ray irradiation during spermatogenic cell cycle was measured by using the methods of terminal deoxyribonucleotide transferase\|mediated dUTP\|bictin nick end labeling (TUNEL) and HE staining. Results\ When an inductive dose (D\-1) of 75 mGy was given or not at 6 h before the challenging dose (D\-2) of 1\^0,2\^0 or 3\^0 Gy,the apoptotic percentages of the spermatogonia and spermatocytes in the D\-1+D\-2 groups were declined rapidly as compared with those in the D\-2 alone groups,and the apoptotic percentages of spermatids showed no significant changes.When the inductive dose (D\-1) 75 mGy was given at 3,6,12 and 24 h before the challenging doses (D\-2) of 1\^0,1\^5,2\^0,2\^5 and 3\^0 Gy,the apoptotic percentages in spermatogonia and spermatocytes reduced early and significantly and continued for a longer duration under smaller D\-2 doses (1\^0,1\^5 and 2\^0 Gy).However,the apoptotic percentages reduced only at 6 h after whole\|body irradiation under larger D\-2 doses (2\^5 and 3\^0 Gy),and were not significant. Conclusions\ The adaptive response of apoptosis in spermatogonia and spermatocytes could be induced by low doses X\|ray irradiation.The effect could closely relate to D\-2 doses and the interval time between D\-1 and D\-2.