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.
The Centre for Neuroendocrinology, Department of Anatomy and Structural Biology, The University of Otago, P.O. Box 913, Dunedin, New Zealand.
Gail C
GC
O'Connell
Shirley A
SA
Douglas
Stephen J
SJ
Bunn
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