Ν-硝基-L-精氨酸甲酯对大鼠隐睾生殖细胞凋亡的保护作用

Protective Effect of Nitric Oxide Synthase Inhibitor (L-NAME) on Germ Cell Apoptosis in Experimentally Cryptorchid Rats

目的 :探讨一氧化氮合酶 (NOS)抑制剂N 硝基 L 精氨酸甲酯 (L NAME)对大鼠隐睾生殖细胞凋亡的保护作用。 方法 :用 2 2dSD雄性大鼠复制单侧隐睾模型。实验分假手术组、隐睾组、隐睾 +L NAME组 [术后腹腔注射L NAME ,10mg/(kg·d) ],每组大鼠各 10只。术后 7d ,用生物素 dUTP/酶标亲和素测定法检测睾丸生殖细胞凋亡 ,用硝酸还原酶法测定睾丸组织中N0含量 ,用化学比色法测定睾丸组织中NOS活性。 结果 :术后第 7d ,与假手术组睾丸相比 ,隐睾组睾丸发生凋亡的生殖细胞数显著增加 ,隐睾 +L NAME组睾丸发生凋亡的生殖细胞数比隐睾组显著减少 (P <0 .0 1) ,隐睾 +L NAME组睾丸组织中NO含量及NOS活性与隐睾组相比显著降低 (P<0 .0 1)。 结论 :隐睾组织中NO和NOS升高是隐睾生殖细胞凋亡增加的病理机制之一 ,L NAME通过抑制NOS活性、减少NO的产生来降低睾丸组织生殖细胞的凋亡发挥其保护作用。

Objective: To explore the protective effect of nitric oxide synthase inhibitor (L NAME) on the germ cell apoptosis in the rat cryptorchid. Methods: Immature rats (22 day old Sprague Dawley) were subjected to unilateral cryptorchid. Thirty rats were divided into three groups: sham operation group (testes still in the scrotum after operation ); operation group; operation + L NAME group(given L NAME 10 mg/kg after operation, dip). Seven days after operation germ cell apoptosis was detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling(TUNEL).Biochemical parameters (NO, NOS) were evaluated with spectrophotometric determination. Results: At the 7th day after the operation, compared with the control, the number of apoptotic germ cells in the cryptorchid testis was increased significantly, but the testis weight was decreased predominantly( P < 0.01 ). The levels of NO and NOS in the cryptorchid were significantly higher than the control. Conclusions: The levels of NO and NOS might be involved in the germ cell apoptosis in the cryptorchid; L NAME could protect the germ cell from apoptosis in experimentally cryptorchid rats by reducing the activity of NOS and reducing the level of NO in the testis.