Inano H, Suzuki K, Ishii-Ohba H, Imada Y, Kumagai R, Kurihara S, Sato A
National Institute of Radiological Sciences, Chiba-shi, Japan.
Radiat Res. 1989 Feb;117(2):293-303.
Pregnant rats received whole-body irradiation at 20 days of gestation with 2.6 Gy lambda rays from a 60Co source. Endocrinological effects before maturation were studied using testes and adrenal glands obtained from male offspring and ovaries from female offspring irradiated in utero. Seminiferous tubules of the irradiated male offspring were remarkably atrophied with free germinal epithelium and containing only Sertoli cells. Female offspring also had atrophied ovaries. Testicular tissue obtained from intact and 60Co-irradiated rats was incubated with 14C-labeled pregnenolone, progesterone, 17 alpha-hydroxyprogesterone, and androstenedione as a substrate. Intermediates for androgen production and catabolic metabolites were isolated after the incubation. The amounts of these metabolites produced by the irradiated testes were low in comparison with the control. The activities of delta 5-3 beta-hydroxysteroid dehydrogenase, 17 alpha-hydroxylase, C17,20-lyase, and delta 4-5 alpha-reductase in the irradiated testes were 30-40% of those in nonirradiated testes. Also, the activities of 17 beta- and 20 alpha-hydroxysteroid dehydrogenases were 72 and 52% of the control, respectively. In adrenal glands, the 21-hydroxylase activity of the irradiated animals was 38% of the control, but the delta 5-3 beta-hydroxysteroid dehydrogenase activity was comparable to that of the control. On the other hand, the activity of delta 5-3 beta-hydroxysteroid dehydrogenase of the irradiated ovary was only 19% of the control. These results suggest that 60Co irradiation of the fetus in utero markedly affects the production of steroid hormones in testes, ovaries, and adrenal glands after birth.
妊娠大鼠在妊娠20天时接受来自60Co源的2.6 Gy λ射线全身照射。利用从子宫内受照的雄性后代获得的睾丸和肾上腺以及雌性后代的卵巢，研究成熟前的内分泌效应。受照雄性后代的生精小管明显萎缩，生精上皮游离，仅含有支持细胞。雌性后代的卵巢也发生萎缩。将从完整大鼠和60Co照射大鼠获得的睾丸组织与14C标记的孕烯醇酮、孕酮、17α-羟孕酮和雄烯二酮作为底物一起孵育。孵育后分离雄激素产生的中间体和分解代谢产物。与对照组相比，受照睾丸产生的这些代谢产物的量较低。受照睾丸中δ5-3β-羟类固醇脱氢酶、17α-羟化酶、C17,20-裂解酶和δ4-5α-还原酶的活性分别为未受照睾丸的30%-40%。此外，17β-和20α-羟类固醇脱氢酶的活性分别为对照组的72%和52%。在肾上腺中，受照动物的21-羟化酶活性为对照组的38%，但δ5-3β-羟类固醇脱氢酶活性与对照组相当。另一方面，受照卵巢中δ5-3β-羟类固醇脱氢酶的活性仅为对照组的19%。这些结果表明，子宫内胎儿接受60Co照射会显著影响出生后睾丸、卵巢和肾上腺中类固醇激素的产生。
