[The effects of extremely low frequency electromagnetic field exposure on the pH of the adult male semen and the motoricity parameters of spermatozoa in vitro].

OBJECTIVE: To study the effects of 50-Hz extremely low frequency electromagnetic field (ELF-EMF) exposure on the pH of the adult male semen and the motoricity and motoricity parameters of spermatozoa. METHODS: Healthy adult male fresh semen was exposed to a 50-Hz EMF at 0.4 mT for 15, 30 and 60 min, respectively. The pH value of the semen, the motoricity and motoricity parameter of spermatozoa were detected and recorded in real time using the WLJY-9000 pattern chromatic color spermatozoa quality detection system. RESULTS: Compared with parallel control group, the exposure of adult male fresh semen to a 50-Hz EMF at 0.4 mT for 15 min or 60 min could decrease significantly the motoricity (spermatozoa with a + b lever) and the activity ratio (spermatozoa with a + b + c lever)(P < 0.01). However, there were no significant differences of motoricity and the activity ratio between exposure group and control group (P > 0.05), and after exposure to a 50-Hz. EMF for 30 min the motoricity and the activity ratio of exposure group were inhibited, as compared with control group (P < 0.01 or P < 0.05). The pH value of the semen was not obvious changed (P > 0.05) when semen was exposed to a 50-Hz EMF of 0.4 mT for 15, 30 and 60 min. CONCLUSION: In present experiment, it is suggested that the exposure of adult male fresh semen to a 50-Hz EMF in vitro could inhibit the motoricity and the activity ratio, but not affect the pH value of the semen within 60 min.

[Expression of estrogen receptor, progesterone receptor and leukemia inhibitory factor on endometrium during different ovarian stimulation protocols in mice].

OBJECTIVE: To evaluate the influence of superovulation by GnRHa protocol and pregnant mare's serum gonadotropin (PMSG) alone on the expression of estrogen receptor (ER), progesterone receptor (PR) and leukemia inhibitory factor (LIF) mRNA on endometrium. METHODS: Forty-five female ICR mice were randomly allocated into 3 groups:(1) GnRHa+PMSG group: alarelin was give first for desensitizing the pituitary, then superovulation with PMSG; (2) PMSG group: mice were injected with PMSG only; (3) Natural cycle group: mice were given with same volume of saline. Endometrium samples were taken at 48 hours after given hCG or ovulation (control group). ER and PR in glandular cells were detected with SP immunohistochemistry semiquantitatively. Expression of LIF mRNA on endometrium was detected with reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. RESULT: The positive rate(%) and expression intense (AU) of ER and PR on glandular epithelium cells were significantly lower in GnRHa+PMSG group and PMSG group than those in natural cycle group (all P <0.01). The expression of LIF mRNA was significantly lower in GnRHa+PMSG group and PMSG group than that in natural cycle group (all P <0.01); but the expressions of ER, PR and LIF in GnRHa+PMSG group were higher than those in PMSG group. CONCLUSION: The protocol with GnRHa down regulates the expressions of ER, PR and the LIF mRNA on the mice of secretive phase endometrium, suggesting it may have an adverse effect on the endometrial receptivity in mice, but it may still be better than PMSG alone.

[Noise magnetic fields mitigates the inhibition of secretion function of primary human villous trophoblasts induced by 50 Hz magnetic fields].

OBJECTIVE: To explore the effects of 50 Hz sinusoidal magnetic fields (MF) on secretion function of primary human villous trophoblasts in vitro, and the interference effect of "noise" MF. METHODS: The trophoblasts were isolated from human villus by trypsin digestion and incubated in DMEM medium.Then the trophoblasts were exposed to 0.4 mT 50 Hz MF and/or "noise" MF respectively for different durations. Each exposure group was matched with one control group which was from the same villus and cultured with the same condition except the MF exposure. The concentrations of human chorionic gonadotropin (HCG) and progesterone in the culture medium were measured by immunofluorescence. Statistical significance of differences between means was determined by one way-ANOVA with P<0.05 considered significant. RESULT: 50 Hz MF inhibited the HCG and progesterone secretion significantly when exposure for 72 h (compared with control group, P<0.05). There was no significant change of HCG and progesterone secretion when trophoblasts were exposed to 0.4 mT "noise" MF within 72 h (compared with control group, P>0.05). However, by superimposing the "noise" MF, the inhibition of HCG and progesterone secretion of trophoblasts induced by 50 Hz MF was eliminated. CONCLUSION: The exposure to 50 Hz MF for long period could inhibit trophoblasts secreting HCG and progesterone, and the "noise" MF with the same intensity could eliminate the effects induced by 50 Hz MF.

[Effects of 50 Hz magnetic fields exposure on secretion of primary human villous trophoblasts].

OBJECTIVE: To explore the possible effects of 50 Hz magnetic fields (MF) exposure on HCG and progesterone secretion of human villous trophoblasts in vitro. METHODS: The trophoblasts were isolated from human villus by trypsin digestion and incubated in DMEM medium. Then the trophoblasts were exposed to 0.2 mT, 0.4 mT 50 Hz MF for 6 h, 12 h, 24 h, 48 h and 72 h, respectively. Each exposure group was matched to one control group which was from the same villus and cultured with the same condition except the 50 Hz MF exposure. The concentration of human chorionic gonadotropin (HCG) and progesterone in the culture medium was detected by electrochemiluminescence immunoassay. Statistical significance of differences between means was determined by one way-ANOVA with P < 0.05 considered significant. RESULTS: Exposure of trophoblasts to 50 Hz MF at 0.2 mT intensity within 72 h did not affect the secretion level of HCG and progesterone (compared with blank control, P > 0.05). There was also no significant change of the secretion level of HCG and progesterone when trophoblasts were exposed to 0.4 mT 50 Hz MF within 48 h (compared with blank control, P > 0.05). However, 50 Hz MF inhibited the HCG and progesterone secretion significantly with exposure for 72 h (compared with blank control, P < 0.05). CONCLUSION: The exposure to 50 Hz MF for long period could inhibit trophoblasts excreting the HCG and progesterone, and the threshold intensity may be between 0.2 mT and 0.4 mT.

[Apoptosis-related gene expression of human villous trophoblasts exposed to 50 Hz magnetic field].

OBJECTIVE: To study apoptosis-related gene expression of human villous trophoblasts exposed to 50 Hz magnetic field and to investigate the possible mechanism of human reproductive health effects caused by 50 Hz magnetic field. METHODS: Cultured human villous trophoblasts were exposed to 50 Hz magnetic field at 0.4 mT for 6, 48, 72 hours. Gene expressions of Bcl-2, Bax, Caspase-3, p53 and Fas were analyzed using real-time reverse transcription polymerase chain reaction (RT-PCR) assay. RESULTS: Within 72 hours, the average fold change for each gene was near 1.00, and there was no significant difference on expression pattern in each gene between exposure and control groups (P > 0.05). CONCLUSION: 0.4 mT 50 Hz magnetic field does not affect the apoptosis-related gene expression of human villous trophoblasts in vitro.

GABA, progesterone and zona pellucida activation of PLA2 and regulation by MEK-ERK1/2 during acrosomal exocytosis in guinea pig spermatozoa.

We investigated whether GABA activates phospholipase A2 (PLA2) during acrosomal exocytosis, and if the MEK-ERK1/2 pathway modulates PLA2 activation initiated by GABA, progesterone or zona pellucida (ZP). In guinea pig spermatozoa prelabelled with [14C]arachidonic acid or [14C]choline chloride, GABA stimulated a decrease in phosphatidylcholine (PC), and release of arachidonic acid and lysoPC, during exocytosis. These lipid changes are indicative of PLA2 activation and appear essential for exocytosis since inclusion of aristolochic acid (a PLA2 inhibitor) abrogated them, along with exocytosis. GABA activation of PLA2 seems to be mediated, at least in part, by diacylglycerol (DAG) and protein kinase C since inclusion of the DAG kinase inhibitor R59022 enhanced PLA2 activity and exocytosis stimulated by GABA, whereas exposure to staurosporine decreased both. GABA-, progesterone- and ZP-induced release of arachidonic acid and exocytosis were prevented by U0126 and PD98059 (MEK inhibitors). Taken together, our results suggest that PLA2 plays a fundamental role in agonist-stimulated exocytosis and that MEK-ERK1/2 are involved in PLA2 regulation during this process.