Possible involvement of the endocannabinoid system in the regulation of uterine contractile activity in pregnant women and induction of labor

Endocannabinoids (ECs), i.e. anandamide (N-arachidonoylethanolamide, or AEA) and 2-arachidonoylglycerol (2-AAG), were discovered in 1992. They form the endocannabinoid system, which includes cannabinoid receptors (CB1- and CB2-), vanilloid receptors (TRPV1), receptors activated by peroxisome proliferators (PPARα, PPARγ), as well as enzymes that synthesize ECs from arachidonic acid and enzymes that degrade ECs. Studies performed in the last 30 years have shown that this remarkable system plays an important role in humans and animals, and is probably relevant to processes in male and female reproduction. This review focuses on little-studied issues such as the involvement of the EC system in conception and gestation, regulation of uterine contractile activity (UCA), and induction of labor in women. Taking into account the ability of ECs to inhibit the contraction activity of uterus of pregnant women and participate in the induction of labor, the interaction of the EC system with the beta-adrenoreceptor myometrial inhibitory mechanism (β-ARMIM) and the NO system, which contribute to gestation, is discussed.