Cyclophosphamide (CYP) is one of the alkylating chemotherapeutic agents and its adverse effects on folliculogenesis in the ovary are well-known due to the previous scientific research on this topic. Magnesium has various effects in organisms, including catalytic functions on the activation and inhibition of many enzymes, and regulatory functions on cell proliferation, cell cycle, and differentiation. In this study, the effects of magnesium sulfate (MgSO4) on CYP induced ovarian damage were investigated. Immature Wistar-Albino female rats of 28-days were treated with pregnant mare serum gonadotrophin (PMSG) to develop the first generation of preovulatory follicles. Rats of the experimental groups were then treated with either CYP (100 mg/kg, i.p) and MgSO4 (270 mg/kg loading dose; 27 mg/kg maintenance doseX12, i.p) solely or in combination. Following in-vivo 5-bromo-2-deoxyuridine (BrdU) labeling, animals were sacrificed and ovaries were embedded in paraffin and Epon. In the ovaries, added to the evaluation of general morphology and follicle count; BrdU and TUNEL-labeling, cleaved caspase-3 and p27 (cyclin-dependent kinase inhibitor) staining was also performed immunohistochemically and an ultrastructural evaluation was performed by transmission electron microscopy (TEM). The number of primordial follicles were decreased and multilaminar primary and atretic follicles were increased in CYP group. After MgSO4 treatment, while primordial follicle pool were elevated, the number of atretic follicles were decreased. Additionally, decreased BrdU-labeling, increased cleaved caspase 3 immunoreactivity and increased TUNEL labeling were observed in CYP group. In CYP treated animals, observations showed that while MgSO4 administration caused no alterations in BrdU proliferation index and caspase-3 immunoreactivity, it significantly reduced the TUNEL labeling. It was also observed that, while p27 immunoreactivity significantly increased in the nuclei of granulosa and theca cells in the CYP group; MgSO4 treatment significantly reduced these immunoreactivities. The ultrastructural observations showed frequent apoptotic profiles in granulosa and theca cells in both early and advanced stages of follicles in the CYP group and the MgSO4 treatment before the CYP application led to ultrastructural alleviation of the apoptotic process. In conclusion, our data suggest that MgSO4 may provide an option of pharmacologic treatment for fertility preservation owing to the beneficial effects of on chemotherapy-induced accelerated follicular apoptotic process, and the protection of the primordial follicle pool.

中文翻译：

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硫酸镁对环磷酰胺引起的卵巢损害的影响：卵泡形成。

环磷酰胺（CYP）是一种烷基化化学治疗剂，由于对该主题的先前科学研究，其对卵巢卵泡生成的不利影响是众所周知的。镁在生物体中具有多种作用，包括对许多酶的激活和抑制起催化作用，对细胞增殖，细胞周期和分化具有调节作用。在这项研究中，研究了硫酸镁（MgSO4）对CYP诱导的卵巢损伤的影响。用怀孕的母马血清促性腺激素（PMSG）处理28天未成熟的Wistar-Albino雌性大鼠，以发育第一代排卵前卵泡。然后单独或组合用CYP（100 mg / kg，ip）和MgSO4（270 mg / kg负载剂量; 27 mg / kg维持剂量X12，ip）治疗实验组的大鼠。体内进行5-溴-2-脱氧尿苷（BrdU）标记后，处死动物并将卵巢包埋在石蜡和Epon中。在卵巢中，增加了对一般形态和卵泡计数的评估；BrdU和TUNEL标记，裂解的caspase-3和p27（细胞周期蛋白依赖性激酶抑制剂）染色也进行了免疫组织化学染色，并通过透射电子显微镜（TEM）进行了超微结构评估。CYP组的原始卵泡数目减少，多层初级和闭锁卵泡增加。MgSO4处理后，虽然原始卵泡池增加，但闭锁卵泡的数量却减少了。另外，在CYP组中观察到BrdU标记降低，半胱天冬酶3切割的免疫反应性增加和TUNEL标记增加。在CYP治疗的动物中，观察结果表明，虽然使用MgSO4不会引起BrdU增殖指数和caspase-3免疫反应性的改变，但会显着降低TUNEL标记。还观察到，CYP组的颗粒细胞核和卵泡膜细胞中的p27免疫反应性显着增加。硫酸镁处理显着降低了这些免疫反应性。超微结构观察结果表明，CYP组卵泡的早期和晚期均存在颗粒和卵泡膜细胞频繁的凋亡特征，而在CYP施用前使用MgSO4处理可导致凋亡过程的超微结构缓解。综上所述，