[Sexual hormone levels in semen and germ cell apoptosis].

OBJECTIVE: To explore the relationship between sexual hormones in semen and germ cell apoptosis in male population. METHODS: Sixty-six infertile patients and thirty fertile males were selected randomly. The levels of folicle stimulating hormone ( FSH), prolactin (PRL), luteinizing hormone (LH), and testosterone (T) in semen were measured by ELISA. Terminal deoxynucleotidyl transferase mediated UTP nick end labeling (TUNEL) was used for the detection of germ cell apoptosis. RESULTS: The levels of FSH, LH, PRL, T in thirty fertile men were (1.63 +/- 0.15) U/L, (2.18 +/- 0.21) U/L, (6.34 +/- 0.30) nmol/L, (1.85 +/- 0.11) nmol/L, respectively, and germ cell apoptosis rate was (4.61 +/- 1.23)%. FSH, LH, PRL, T levels in infertile group were (1.25 +/- 0.18) U/L, (1.76 +/- 0.32) U/L, (5.86 +/- 0.13) nmol/l, (1.45 +/- 0.13) nmol/, respectively, and germ cell apoptosis rate was (18.36 +/- 2.04)%. There were significant differences in all parameters between infertile group and fertile group. The levels of FSH, LH, PRL, T were negatively correlated with germ cell apoptosis rates( r = -0.88, -0.93, -0.90, -0.98). The volume of apoptotic germ cell decreased, and chromatin was compacted to form cell-membrane blebs and apoptotic bodies. CONCLUSION: Low concentration of sexual hormones may increase the apoptosis of germ cells, which can induce male infertility.

[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.

[Sodium nitroprusside facilitates human sperm capacitation and acrosome reaction].

OBJECTIVE: To explore the effect of nitric oxide (NO) on human sperm capacitation and acrosome reaction (AR). METHODS: Different concentrations of sodium nitroprusside (SNP) were added to the sperm suspension from 48 healthy fertile men, and the suspension was incubated in 1 x Earle at 37 degrees C for 1 hour. Progesterone was used to induce AR for 15, 30, 45 and 60 min, and then acid phosphatase (ACP) activity in the suspension before and after capacitation and at different time of AR was measured by p-nitrophenyl sodium phosphate assay. In the meantime, sperm motile parameters were assayed by CASA to observe sperm capacitation and AR. RESULTS: ACP activity and sperm motile parameters increased in the 50 approximately 100 nmol/L NO concentration group, showed no significant variation in the 150 approximately 200 nmol/L group, and decreased in the 250 approximately 300 nmol/L group. CONCLUSION: NO can facilitate sperm capacitation, AR and sperm motile parameters in low concentration and suppress them in high concentration. ACP activity assay of sperm is an objective and reliable method to evaluate sperm capacitation and AR in whole sperm population.