Jégou B, Velez de la Calle J F, Bauché F
Groupe d'Etude de la Reproduction chez le Mâle, Unité de Recherche Associée 256, Centre National de la Recherche Scientifique, Université de Rennes I, Bretagne, France.
Proc Natl Acad Sci U S A. 1991 Oct 1;88(19):8710-4. doi: 10.1073/pnas.88.19.8710.
This study attempted to protect spermatogenesis and the reproductive performance of rats against the effects of acute scrotal exposure to x-rays. Daily subcutaneous injections of medroxyprogesterone acetate (8 mg/kg) plus testosterone (1 mg/kg) (MT group) were administered for 55 days (experiment A) or 15 days (experiment B). The rats were irradiated (3 grays) on the last day of MT pretreatment (MTX group). In both experiments, on days 1 and 130 posttreatment, rats from each of the four groups (control, x-irradiated, MT, and MTX groups) were killed to measure the weight of the reproductive organs and the number of epididymal spermatozoa. Breeding was started 3 days posttreatment by housing all males from the four groups each with two virgin females for six successive periods of 19 days, separated by a period of 2 days. The percentage of fertile males, the litter size, postimplantation losses, and dominant lethal mutations were calculated. In experiment A, in the last fertility trial, animals of both sexes were selected at random from the progeny of each group (F1). When they were adults, their fertility was tested in a mating trial. A fertility trial was also performed with the F2 males. Our data essentially reveal that (i) in addition to their adverse quantitative effects on spermatogenesis, x-rays also produce a significant increase in dominant lethal mutations in all germ cell classes, including stem spermatogonia; (ii) the F1 and F2 male descendants of irradiated male rats provoked abnormal rates of postimplantation losses in their female mates; (iii) the short as well as the long MT pretreatment protects testicular function of irradiated rats; and (iv) in experiment A, MT pretreatment totally prevented qualitative damage to spermatozoa and protected the descendants of the irradiated animals against altered spermatogenesis as well as against genetic damage in germ cells. In conclusion, pretreatment with MT, even for a short period of time, offers a method for potentially reducing the toxic and genotoxic effects of irradiation on the male reproductive system.
本研究试图保护大鼠的精子发生及生殖性能，使其免受阴囊急性暴露于X射线的影响。每日皮下注射醋酸甲羟孕酮（8毫克/千克）加睾酮（1毫克/千克）（MT组），持续55天（实验A）或15天（实验B）。在MT预处理的最后一天对大鼠进行照射（3戈瑞）（MTX组）。在两个实验中，于处理后第1天和第130天，处死四组（对照组、X射线照射组、MT组和MTX组）中的每组大鼠，以测量生殖器官重量及附睾精子数量。处理后3天开始繁殖，将四组的所有雄性大鼠分别与两只未交配过的雌性大鼠合笼，连续进行六个为期19天的周期，中间间隔2天。计算可育雄性的百分比、窝仔数、植入后损失率和显性致死突变率。在实验A中，在最后一次生育试验中，从每组（F1）的后代中随机挑选雌雄动物。当它们成年后，在交配试验中测试其生育能力。还对F2雄性进行了生育试验。我们的数据基本上表明：（i）除了对精子发生有不利的定量影响外，X射线还会使包括精原干细胞在内的所有生殖细胞类别中的显性致死突变显著增加；（ii）受照射雄性大鼠的F1和F2雄性后代会使其雌性配偶的植入后损失率异常；（iii）短期和长期的MT预处理均可保护受照射大鼠的睾丸功能；（iv）在实验A中，MT预处理完全防止了精子的定性损伤，并保护了受照射动物的后代免受精子发生改变以及生殖细胞遗传损伤的影响。总之，即使是短时间的MT预处理，也提供了一种潜在的方法来降低辐射对雄性生殖系统的毒性和遗传毒性作用。
