The involvement of specific phospholipase C isozymes in catecholamine release from digitonin permeabilized bovine adrenal medullary chromaffin cells.
The role of phospholipase C (PLC) in exocytosis has been investigated using digitonin permeabilized, [(3)H]noradrenaline ([(3)H]NA) loaded, bovine adrenal medullary chromaffin cells. The PLC inhibitor U-73122 caused a concentration-dependent suppression of Ca(2+)-evoked [(3)H]NA release but increased basal release (that occurring in the absence of Ca(2+)). Preincubation with antibodies against PLCgamma1 or PLCbeta3 (but not PLCdelta1, delta2, beta1 and beta2) also inhibited [(3)H]NA release evoked by Ca(2+) and increased basal release, indicating that only specific PLC isozymes are involved in these actions. Interestingly, PLCgamma1 (but not PLCbeta3) antibodies inhibited the ability of Ca(2+) to increase PLC activity in these permeabilized cells. These data therefore suggest that PLCgamma1 activity may have a specific role in regulating the exocytotic response from the adrenal chromaffin cell.
O'Connell
Gail C
GC
The Centre for Neuroendocrinology, Department of Anatomy and Structural Biology, The University of Otago, P.O. Box 913, Dunedin, New Zealand.
Douglas
Shirley A
SA
Bunn
Stephen J
SJ
D000313:Adrenal Medulla / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D018929:Cell Culture Techniques; D002463:Cell Membrane Permeability; D019439:Chromaffin Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D004072:Digitonin / Q000378:metabolism; D004963:Estrenes / Q000494:pharmacology; D005089:Exocytosis / Q000187:drug effects; D007527:Isoenzymes / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D054799:Phospholipase C beta; D051966:Phospholipase C gamma; D011760:Pyrrolidinones / Q000494:pharmacology; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D004963:Estrenes; D007527:Isoenzymes; D010726:Phosphodiesterase Inhibitors; D011760:Pyrrolidinones; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D010738:Type C Phospholipases; D054799:Phospholipase C beta; D051966:Phospholipase C gamma; D004072:Digitonin; D002118:Calcium; D009638:Norepinephrine