Polychlorinated biphenyls impair FSH-stimulated effect on the secretion of steroids and oxytocin from cultured bovine granulosa cells

Follicular fluid (FF) was collected by aspiration from bovine follicles at slaughterhouse and PCBs (IUPAC number 28, 52, 101, 118, 153, 138, and 180) were determined by gas chromatography. Total amount of PCB never exceeded 0.11 ng/ml of FF, thus we assume the granulosa cells we used in the further studies were not influenced by PCBs. In next experiment the effect of PCB 126, 77 or 153 (each at the dose 1, 10 i 100 ng/ml) for 72 h on the secretion of oestradiol (E2), progesterone (P4) or oxytocin (OT) from non-stimulated or stimulated with FSH (100 ng/ml for last 24 h) granulosa cells (2x10(5)/ml), obtained from bovine follicles > 1 < cm in diameter. Each of the used congeners could reduce (P < 0.05) effect of FSH on E2 secretion and influence by PCB 153 in follicles of < 1cm in diameter was the most evident (P < 0.05). All used PCBs, but PCB 153 in cultures of granulosa cells from follicles > 1cm decreased the effect of FSH on the secretion of P4. Each of used congeners stimulated OT secretion from granulosa of both sizes follicles and PCB 77 was the most efficient in this case (P < 0.01-0.001). Data suggest that PCBs can impair growth and development of follicle by blockade of FSH effect on granulosa cells. Moreover, glucocorticoid and SF-1 receptors are suppose to be also involved in PCBs influence on OT secretion by bovine granulosa cells.