男性不育精液中NO的含量与生殖细胞凋亡的关系

目的:探讨人精液中一氧化氮(nitricoxide,NO)与生殖细胞凋亡的关系。方法:采用镀铜镉还原荧光法检测NO代谢产物硝酸盐(NO-3)。用脱氧核苷酸末端转移酶(TdT)介导的缺口末端标记(TUNEL)法和透射电镜,分别检测和观察生殖细胞的凋亡及凋亡细胞的超微结构。结果:生育组精液中NO的含量为(56.83±11.65)μmol/L,生殖细胞的凋亡率(4.60±1.25)%,与不育组(128.86±23.76)μmol/L和(17.36±3.05)%相比较有非常显著性差异(P<0.01)。不育组NO的含量和生殖细胞的凋亡率呈显著的正相关(r=0.96)凋亡的生殖细胞核染色质浓缩在核周形成新月形,电子密度增高,核膜折叠,核裂解形成凋亡小体。结论:不育者精液中NO的含量与生殖细胞的凋亡率有密切关系。高浓度的NO可能是导致睾丸生殖细胞凋亡率增加而致使男性生育力下降的原因。

Relationship between the amount of nitric oxide and apoptosis of germ cells in the semen of infertile men

AIM: To explore the relationship between nitric oxide(NO) and apoptosis of germ cells in the semen of infertile men. METHODS: Copper-coated cadmium reduction fluorescence assay was used to detect nitrate, the metabolic product of NO. The apoptosis and ultrastructure of germ cells were detected and observed by TdT-mediated dUTP nick end labeling (TUNEL) and transmission electronls microscope (TEM), respectively. RESULTS: In normal control group, concentration of NO and the apoptotic rate of germ cells were (56.83+/-11.65) micromol/L and (4.60+/-1.25)%, respectively; while in inferile group were (128.86+/-23.76) micromol/L and (17.36+/-3.05)%, respectively. The differences in NO concentration and the apoptotic rate of germ cells between the two groups were significant (P<0.01). The concentration of NO was positively correlated with the apoptotic rate of germ cells in infertile group (r=0.96). The apoptotic germ cells showed typical morphology of apoptosis, including nuclear chromatin condensation and margination, nuclear memberane folding, and formation of apoptotic bodies. CONCLUSION: The amount of NO in semen from infertile men has close relationship with apoptotic rate of germ cells. High concentration of NO may result in the increase of germ cell apoptosis rate and lead to male infertility.