The inhibition of myometrial contractions by chlorinated herbicides (atrazine and linuron), and their disruptive effect on the secretory functions of uterine and ovarian cells in cow, in vitro.

The effect of atrazine and linuron, the popular and widely used chlorinated herbicides, on both myometrial contractions and secretory functions of bovine uterus and ovaries in vitro, was investigated. The pesticides inhibited (P<0.05) the basal and oxytocin (OT)-stimulated myometrial strips contractions, as well as the effect of OT on secretion of prostaglandins (PGs: PGF2α and PGE2) from endometrium. But only linuron inhibits the effect of OT on myometrial contractions. Neither of herbicides affected PGs secretion from myometrium and PGF2α from endometrium. Only the lowest dose of both tested compounds decreased PGE2 secretion from endometrium. The pesticides increased (P<0.05) the OT secretion from granulosa. However, only linuron stimulated (P<0.05) the OT secretion from the luteal cells, and it increased (P<0.05) the expression of mRNA for the OT precursor. Both compounds stimulated (P<0.05) the secretion of testosterone and atrazine increased (P<0.05) also the secretion of estradiol from the granulosa cells. While atrazine and linuron reduced (P<0.05) the progesterone secretion from the luteal cells. The data show that atrazine and linuron altered the secretory functions of ovarian cells and inhibited the myometrial contractions in vitro.