低剂量辐射诱导小鼠睾丸生精细胞凋亡的适应性反应

Adaptive response of spermatogenic cell apoptosis induced by low dose X-ray irradiation in mice

目的 研究低剂量电离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、1 2、2 4h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在照后 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

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.\;