The aim of this study was to evaluate the effect of prolonged dietary nitrate supplementation on the gonadotropin level, testicular histology and morphometry, expression of miR-34b and p53 mRNA, and spermatogenesis in streptozotocin-induced diabetic male rats. METHODS Fifty male Wistar rats were divided into 5 groups: Control (C), control + nitrate (CN), diabetes (D), diabetes + insulin (DI), and diabetes + nitrate (DN). Diabetes was induced using 45 mg kg-1 of streptozotocin intraperitoneally. Rats in the CN and DN groups were administered sodium nitrate in drinking water (100 mg L-1). NPH insulin (2-4 U d-1) was injected subcutaneously in the DI group for 2 months. Nitrate and insulin supplementation was started one month after confirmation of diabetes. RESULTS Nitrate supplementation in the DN group significantly increased the body weight (p < 0.05), sperm parameters (p < 0.001), indices of spermatogenesis (p < 0.001), and testis histopathology as well as decreased the blood glucose level (p < 0.001) compared to the untreated diabetic group, although it had no significant effect on testicular parameters, LH and FSH levels. Nitrate administration in the DN group also decreased miR-34b (p < 0.001) and p53 mRNA (p < 0.001) expression, and increased serum insulin and NOx levels compared to the untreated diabetic rats. CONCLUSIONS Chronic nitrate supplementation in streptozotocin-induced diabetic rats improved fertility parameters, which may be associated with increased miR-34b and decreased p53 mRNA.

中文翻译：

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长期饮食性硝酸钠治疗对链脲佐菌素诱发的糖尿病雄性大鼠下丘脑-垂体-性腺轴及睾丸结构和功能的影响。

这项研究的目的是评估长期补充硝酸盐对链脲佐菌素诱发的糖尿病雄性大鼠促性腺激素水平，睾丸组织学和形态，miR-34b和p53 mRNA表达以及精子发生的影响。方法50只Wistar雄性大鼠分为5组：对照组（C），对照组+硝酸盐（CN），糖尿病（D），糖尿病+胰岛素（DI）和糖尿病+硝酸盐（DN）。腹膜内使用45 mg kg-1的链脲佐菌素诱导糖尿病。CN和DN组的大鼠在饮用水（100 mg L-1）中施用硝酸钠。DI组皮下注射NPH胰岛素（2-4 U d-1）2个月。确认糖尿病后一个月开始补充硝酸盐和胰岛素。结果DN组补充硝酸盐显着增加了体重（p <0.05），精子参数（p <0.001），精子生成指数（p <0.001）和睾丸组织病理学以及降低了血糖水平（p <0.001） ）与未治疗的糖尿病组相比，尽管它对睾丸参数，LH和FSH水平无明显影响。与未治疗的糖尿病大鼠相比，DN组中的硝酸盐施用还降低了miR-34b（p <0.001）和p53 mRNA（p <0.001）表达，并增加了血清胰岛素和NOx水平。结论在链脲佐菌素诱导的糖尿病大鼠中补充硝酸盐可改善生育力参数，这可能与增加miR-34b和降低p53 mRNA有关。001）和睾丸组织病理学以及降低血糖水平（p <0.001）与未经治疗的糖尿病组相比，尽管它对睾丸参数，LH和FSH水平没有显着影响。与未治疗的糖尿病大鼠相比，DN组中的硝酸盐施用还降低了miR-34b（p <0.001）和p53 mRNA（p <0.001）表达，并增加了血清胰岛素和NOx水平。结论在链脲佐菌素诱导的糖尿病大鼠中补充硝酸盐可改善生育力参数，这可能与增加miR-34b和降低p53 mRNA有关。001）和睾丸组织病理学以及降低血糖水平（p <0.001）与未经治疗的糖尿病组相比，尽管它对睾丸参数，LH和FSH水平没有显着影响。与未治疗的糖尿病大鼠相比，DN组中的硝酸盐施用还降低了miR-34b（p <0.001）和p53 mRNA（p <0.001）表达，并增加了血清胰岛素和NOx水平。结论在链脲佐菌素诱导的糖尿病大鼠中补充硝酸盐可改善生育力参数，这可能与增加miR-34b和降低p53 mRNA有关。与未治疗的糖尿病大鼠相比，DN组中的硝酸盐施用还降低了miR-34b（p <0.001）和p53 mRNA（p <0.001）表达，并增加了血清胰岛素和NOx水平。结论在链脲佐菌素诱导的糖尿病大鼠中补充硝酸盐可改善生育力参数，这可能与增加miR-34b和降低p53 mRNA有关。与未治疗的糖尿病大鼠相比，DN组中的硝酸盐施用还降低了miR-34b（p <0.001）和p53 mRNA（p <0.001）表达，并增加了血清胰岛素和NOx水平。结论在链脲佐菌素诱导的糖尿病大鼠中补充硝酸盐可改善生育力参数，这可能与增加miR-34b和降低p53 mRNA有关。