Ca(2+) signalling by P2Y receptors in cultured rat aortic smooth muscle cells.
OBJECTIVE
P2Y receptors evoke Ca(2+) signals in vascular smooth muscle cells and regulate contraction and proliferation, but the roles of the different P2Y receptor subtypes are incompletely resolved.


METHODS
Quantitative PCR was used to define expression of mRNA encoding P2Y receptor subtypes in freshly isolated and cultured rat aortic smooth muscle cells (ASMC). Fluorescent indicators in combination with selective ligands were used to measure the changes in cytosolic free [Ca(2+)] in cultured ASMC evoked by each P2Y receptor subtype.


RESULTS
The mRNA for all rat P2Y receptor subtypes are expressed at various levels in cultured ASMC. Four P2Y receptor subtypes (P2Y1, P2Y2, P2Y4 and P2Y6) evoke Ca(2+) signals that require activation of phospholipase C and comprise both release of Ca(2+) from stores and Ca(2+) entry across the plasma membrane.


CONCLUSIONS
Combining analysis of P2Y receptor expression with functional analyses using selective agonists and antagonists, we isolated the Ca(2+) signals evoked in ASMC by activation of P2Y1, P2Y2, P2Y4 and P2Y6 receptors.
Govindan
Sriram
S
Department of Pharmacology, Cambridge, UK.
Taylor
Emily J A
EJ
Taylor
Colin W
CW
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism; D020013:Calcium Signaling; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005786:Gene Expression Regulation; D049990:Membrane Transport Modulators / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism*; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D018048:Receptors, Purinergic P2 / Q000235:genetics / Q000378:metabolism*; D058472:Receptors, Purinergic P2Y1; D058473:Receptors, Purinergic P2Y2; D010738:Type C Phospholipases / Q000378:metabolism
D049990:Membrane Transport Modulators; C546384:P2ry1 protein, rat; C546387:P2ry2 protein, rat; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D012333:RNA, Messenger; D018048:Receptors, Purinergic P2; D058472:Receptors, Purinergic P2Y1; D058473:Receptors, Purinergic P2Y2; C104749:purinoceptor P2Y4; C099845:purinoceptor P2Y6; D000255:Adenosine Triphosphate; D010738:Type C Phospholipases