Some properties of a purinergic receptor solubilized from human uterus membranes

Abstract

A purinergic receptor was identified in human myometrium membranes using 5'-~-[3H]ethylcarboxamideadenosine ([3H]NECA) as radioligand. Scatchard analysis of the binding data gave a Kd of 123 nM with 2.3 pmol ligand bound/mg protein. Displacement studies indicated that the binding site had the characteristics of the AZ adenosine receptors and some of those of the P2 purinoceptors since it was inhibited by two slowly degradable ATP derivatives with Z&O values comparable to that of NECA. The receptor was solubilized with sodium cholate and its binding properties were the same as those of the membrane-bound form. No -SH group appeared to be essential for the binding activity. By density gradient centrifugation the purinergic receptor-detergent complex was estimated to have an apparent molecular mass of 95 kDa. Purinergic receptor 5'-N-Ethylcarboxamideadenosine Receptor solubilizationHuman uterus membrane

Purinergic signalling in the reproductive system in health and disease

“…3 H]ethylcarboxamide-adenosine as a radioligand [348]. The binding site had the characteristics of the A 2 adenosine receptor and some of those of P2 receptors too.…”

Distribution of P2X receptor subtypes in the rat female reproductive tract at late pro-oestrus/early oestrus

“…There is evidence that in the female reproductive system ATP, acting through P2 receptors, is utilised as a nonadrenergic, noncholinergic cotransmitter to smooth muscle, and is also released from non-neuronal cells to act on P2 receptors in the myometrium (Ninomiya and Suzuki 1983;Osa and Maruta 1987;Honorè et al 1989;Piper and Hollingsworth 1996;Gillman and Pennefather 1998), and fallopian tube (McBlain and Toft 1983;Tiemann et al 1996). A P2 receptor has also been identified by solubilisation of human uterine membranes (Ronca-Testoni et al 1984). Extracellular ATP has a potential role in the regulation of human fallopian tubal fluid formation and causes a marked increase in cytosolic Ca 2+ concentration from fallopian epithlelial cells (Dickens et al 1996).…”

Purinergic Signalling in the Reproductive System

“…Myometrial cells also express P2 receptors (P2Y 2 , P2Y 4 , P2X 1 , P2X 2/3 , P2X 3 , P2X 4 and P2X 7 ) in a manner that varies among species and changes during the cycle and pregnancy Ronca-Testoni et al, 1984;Smith et al, 1988;Piper and Hollingsworth, 1996;Urabe et al, 2009;Miyoshi et al, 2010Miyoshi et al, , 2012. In the rat, P2X 1 receptor expression is low throughout pregnancy (days 4 to 20), but it increases significantly at day 22 (postpartum day 1) (Khanam and Burnstock, 2007).…”

“…Myometrium P1 receptors are expressed by myometrial smooth muscle cells, including the A 2 in human myometrium membranes (Ronca-Testoni et al, 1984) and the A 2B subtype in the rat myometrium (Gillman and Pennefather, 1998). In rodents, adenosine, acting via P1 receptors, contracts the myometrium (Fleet and Heap, 1982;Smith et al, 1988;Schiemann et al, 1991).…”