OBJECTIVETo observe the effects of fenvalerate (Fen) on ovarian calcium homeostasis.

METHODShGLCs were obtained from pre-ovulatory follicles in an in vitro fertilization program, and were cultured for 72 hours. Changes in cellular [Ca(2+)]i induced by Fen in hGLCs were detected with laser scanning confocal microscopy (LSCM) by using the fluorescent Ca(2+) indicator fluo-3/AM. SD female rats were divided into four groups (control, 1/15LD(50), 1/50 LD(50) and 1/250 LD(50)) in experiment. The activity of ovarian Ca(2+)-ATPase and phosphorylase A (P-a) and the contents of calmodulin (CaM) were assessed after a 30-day Fen exposure. In addition, serum estradiol-17 beta (E(2)) and progesterone (P(0)) concentration were measured by radioimmunoassay, which the sampling rats were ensured at diestrus stage before killed according to vaginal smear.

RESULTS20.0 and 2.0 micromol/L Fen induced the increased of [Ca(2+)]i in hGLC. This [Ca(2+)]i increase mostly resulted from Ca(2+) influx in the studied concentration. Fen had shown the inhibition effects on activity of Ca(2+)-ATPase in 1/250 LD(50) group (P < 0.001) while the activity of phosphorylase A (P-a) in treated groups had significantly enhanced than those of in control. The contents of CaM in ovaries were found to be increased in treated groups. E(2) in 1/250 LD(50) group were higher while P(0) in 1/15 LD(50) group were significantly lower (P < 0.05).

CONCLUSIONExposure to Fen interferes the serum steroid hormone concentrations partly through calcium signal pathway.