The molecular mechanism by which prostaglandine £2 and E. produce their effect on the myometrium are still not clear. One of the possibilities of the mechanism of action of PGs through stimulation of adrenergic receptors. This study was performed to study the effect of exogenous PGE2 and PGF2 on the adrenergic receptor in the non pregnant and pregnant rat uterus. The stimulatory effect of PGF2 is not affected by blocking the adrenergic receptor by adding inderal (beta blocker) or hydergine (aZphablocker). Also the action of PGE2 which is inhibitory to uterine muscle in the non pregnant state and stimulatory during pregnancy is not affected by add¬tion of any of the adrenergic blockers. So we can conclude that PGs do not exert its effect on the rat uterine muscle through adrenergic receptors