Purinergic Signalling in the Reproductive System.

Purinergic effects in vivo are local, specific, transient, and affect target cells in a paracrine or autocrine manner. Purinergic signalling is involved in the regulation of numerous functions in the male and female reproductive tract organs. Analysis of functional expression of purinoceptors suggests that P2Y2 receptors are involved in the regulation of luminal fluid secretion in vivo; P2X1 and P2X2 in the regulation of smooth muscle cell contraction of blood vessels and tubular organs; P2X2 in the regulation of sperm cell maturation; P2X3 in activation of sensory nerve fibers involved in reflex activities and pain; P2X4 in the regulation of tight junctional resistance and epithelial transport in female reproductive tract epithelia, and in the regulation of luminal acidification in the epididymis, vas deferens and probably the vagina and ectocervix; P2Y1 and P2Y2 in the regulation of cell proliferation; P2X5 and P2X7A in the regulation of epithelial cell terminal differentiation and apoptosis; and A1 receptors in the regulation of sperm cell capacitation. Translational studies suggested that cellular levels of the P2X7A receptor could be used as a biomarker for the early detection of breast, ectocervix, endocervix, endometrial and bladder cancers. Data also suggested that the P2X7A mechanism could be used as a pharmaceutical target for the prevention and treatment of epithelial neoplasia through the induction of apoptosis.