Morphological evaluation of the radioprotective effects of melatonin against X-ray-induced early and acute testis damage in Albino rats: an animal model
Morphological evaluation of the radioprotective effects of melatonin against X-ray-induced early and acute testis damage in Albino rats: an animal model
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DOI：
10.1111/j.1365-2613.2006.00480.x
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发表时间：
2006-06-01
影响因子：
3
通讯作者：
Abdelraheem, Mohamad H.
中科院分区：
文献类型：
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作者：
Hussein, Mahmoud R.;Abu-Dief, Eman E.;Abdelraheem, Mohamad H.
辐射对生殖功能有深远的影响。我们对褪黑激素对 X 射线引起的睾丸损伤的辐射防护作用的了解还很初级。在这项研究中，我们假设褪黑激素可以最大限度地减少 X 射线照射 (XRI) 后睾丸中生殖细胞的消耗和细胞损伤的形态特征。为了检验这些影响并检验我们的假设，建立了由 60 只白化大鼠组成的动物模型。将动物分为五组：第 1 组，未受辐射；第 1 组，未受辐射；第 2 组，X 射线照射（XRI，8 格雷）；第3组，用溶剂（乙醇和磷酸盐缓冲盐水）预处理的XRI；第4组，用褪黑激素处理的未照射组，第5组，用褪黑激素预处理的XRI。对睾丸进行组织学（光学显微镜）和超微结构变化（透射电子显微镜）评估。组织学上，XRI 组（第 2 组和第 3 组）生发上皮细胞明显减少（66%），而在用褪黑激素预处理的动物（第 5 组）的 XRI 睾丸中几乎不存在这些变化。用褪黑素预处理的动物（第 5 组）XRI 睾丸中的生精细胞数量与未照射组（第 1 组和第 4 组）相当（95%），但显着（P < 0.05）高于 XRI 睾丸中的生精细胞数量（34%，第 2 组和第 3 组）。从超结构上看，XRI 睾丸（第 2 组和第 3 组）显示细胞凋亡特征（细胞核浓缩、细胞质空泡化、细胞质密度增加和凋亡小体）。用褪黑激素预处理的动物（第 5 组）的 XRI 睾丸中不存在这些特征。此外，该组还表现出代谢活性增加的特征（顶体小泡大、高尔基体突出、有丝分裂活性增加、细胞质细胞器补充增加以及核仁样体的出现）。 XRI 后支持细胞和间质细胞有最小程度的损耗。此外，这些细胞中凋亡的形态学特征并不常见。在照射前服用褪黑激素 (MEL) 可以保护睾丸免受其破坏性影响。保护作用包括改善生殖细胞耗竭和凋亡变化。这些观察结果的临床影响需要进一步研究。
Irradiation has profound effects on the reproductive function. Our knowledge about radioprotective effects of melatonin against X-ray-induced testis damage is rudimentary. In this investigation, we hypothesized that melatonin can minimize germ-cell depletion and morphological features of cell damage in testis following X-ray irradiation (XRI). To examine these effects, and to test our hypothesis, an animal model comprised of 60 Albino rats was established. The animals were divided into five groups: Group 1, non-irradiated; Group 2, X-ray irradiated (XRI, 8 Grays); Group 3, XRI pretreated with solvent (ethanol and phosphate-buffered saline); Group 4, non-irradiated group treated with melatonin and Group 5, XRI pretreated with melatonin. The testes were evaluated for both histological (light microscopy) and ultrastructural changes (transmission electron microscopy). Histologically, there were marked depletions (66%) of the germinal eplithelial cells, in XRI group (Groups 2 and 3), whereas these changes were almost absent in XRI testis of animals pretreated with melatonin (Group 5). The number of spermatogenic cells in XRI testis of animals pretreated with melatonin (Group 5) was comparable (95%) to that of non-irradiated group (Groups 1 and 4) but significantly (P < 0.05) higher than those in XRI testis (34%, Groups 2 and 3). Ultra structurally, XRI testis (Groups 2 and 3) showed features of apoptosis (condensation of the nuclei, vacuolization of the cytoplasm, increased cytoplasmic density and apoptotic bodies). These features were absent in XRI testis of animals pretreated with melatonin (Group 5). Also, this Group showed features of an increased metabolic activity (large acrosomal vesicle, prominent Golgi, increased mitotic activity, increased complement of cytoplasmic organelles and appearance of nucleoli-like bodies). There was a minimal depletion of the Sertoli and Leydig cells following XRI. Also, morphological features of apoptosis were infrequent in these cells. Administration of melatonin (MEL) prior to irradiation can protect testis against its destructive effects. The protective effects include amelioration of germ-cell depletion and apoptotic changes. The clinical ramifications of these observations mandate further studies.