Cannabinoid Induced Changes in Rat Uterine Contractility

endocannabinoids have been demonstrated in many mammalian tissues and are widely distributed in the CNS, peripheral nerves, leukocytes, spleen and testicles.It was reported that exposure to exocannabinoids (e.g. marijuana) is associated with adverse pregnancy outcomes, including spontaneous and preterm labor, fetal growth restriction, and miscarriage. It was also found that cannabinoid receptors are expressed in the oviduct, uterus, and placental membranes. In addition the uterus contains the highest levels of anandamide; the first discovered endocannabinoid, suggesting a particular role of anandamide in reproduction.There are contradictory reports about the effect of cannabinoid agonists on uterine contractility and contradictory reports about the mechanism of this effect. So the present study was designed:• To demonstrate the effect of anandamide on spontaneous contraction of pregnant and non pregnant rat uterus.• To investigate the possible involvement of cannabinoid CB1 receptors, Nitric Oxide (NO), and small conductance Ca+2 activated K+ channels in anandamide induced effect.The present study was carried out on a total number of 30 adult albino rats (24 females and 6 males). The male rats were used for induction of pregnancy. The first day of pregnancy was determined by the presence spermatozoa in the vaginal smear examined microscopically. The female rats were divided into four equal groups each contains 6 rats. Three groups (non pregnant, day 10 and day 19 of gestation) were used to study the effects of anandamide (10-6, 10-5 and 10-4 M/ml organ bath fluid) on spontaneous contractile activity of isolated uterine strips.