Changes in expression of P2X1 receptors and connexin 43 in the rat myometrium during pregnancy.
OBJECTIVE
To investigate the expression of P2X(1) receptors and connexin 43 in gap junctions between smooth muscle cells. Contraction mediated by P2X receptors is known to occur in the bladder and male reproductive tract, and cell-cell coupling of smooth muscle via gap junctions is essential for synchronized rhythmic activity of these tissues.


METHODS
We selected for this study rat myometrial smooth muscle during pregnancy and at postpartum day l.


METHODS
University medical school.


METHODS
Laboratory rats.


METHODS
Rats were mated and became pregnant.


METHODS
Immunostaining and fluorescence and confocal microscopy.


RESULTS
The level of P2X(1) receptor expression remained low throughout pregnancy (days 4 to 20) but was greatly up-regulated at day 22 (postpartum day 1). Connexin 43 expression showed a pattern of up-regulation, with progression through pregnancy and peaking near labor, but exhibited a rapid down-regulation after parturition.


CONCLUSIONS
The functional significance of the changes in connexin 43 and P2X(1) receptor expression that have been observed is discussed in relation to triggering and modulation of uterine contractility during and after pregnancy.
Khanam
Tina
T
Autonomic Neuroscience Centre, Royal Free and University College Medical School, London, United Kingdom.
Burnstock
Geoffrey
G
D000818:Animals; D018031:Connexin 43 / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D009215:Myometrium / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D018048:Receptors, Purinergic P2 / Q000096:biosynthesis* / Q000235:genetics; D058469:Receptors, Purinergic P2X
D018031:Connexin 43; D018048:Receptors, Purinergic P2; D058469:Receptors, Purinergic P2X