Phospholipase Cdelta(1) does not mediate Ca(2+) responses in neonatal rat cardiomyocytes.
Phospholipase C (PLC) activation in neonatal rat ventricular cardiomyocytes (NRVM) generates inositol(1,4,5)trisphosphate (Ins(1,4,5)P(3)) in response to elevations in Ca(2+) or inositol(1,4)bisphosphate in response to G protein stimulation. Overexpression of PLCdelta(1) increased total [(3)H]inositol phosphate (InsP) content and elevated [(3)H]Ins(1,4,5)P(3), but failed to increase [(3)H]InsP responses to the Ca(2+) ionophore A23187. Antisense PLCdelta(1) expression reduced endogenous PLCdelta(1) content but did not decrease the A23187 response. In permeabilized NRVM, [(3)H]InsP responses to elevated Ca(2+) were not inhibited by Ins(1,4,5)P(3), even at concentrations 1000-fold greater than required for selective inhibition of PLCdelta(1). Taken together these data provide evidence that PLCdelta(1) does not mediate the InsP response to elevated Ca(2+) in NRVM.
Woodcock
Elizabeth A
EA
Cellular Biochemistry Laboratory, Baker Heart Research Institute, PO Box 6492, St Kilda Rd Central, Melbourne, Vic 8008, Australia. liz.woodcock@baker.edu.au
Mitchell
Christopher J
CJ
Biden
Trevor J
TJ
D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism*; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D054803:Phospholipase C delta; D051381:Rats; D017207:Rats, Sprague-Dawley; D010738:Type C Phospholipases / Q000378:metabolism*
D007527:Isoenzymes; D015544:Inositol 1,4,5-Trisphosphate; D010738:Type C Phospholipases; D054803:Phospholipase C delta; D002118:Calcium