Histamine-stimulated phospholipase C activity in bovine adrenal medullary chromaffin cells: the effect of chloride-channel antagonists and low extracellular chloride concentrations
El. Roberts-thomson et al., Histamine-stimulated phospholipase C activity in bovine adrenal medullary chromaffin cells: the effect of chloride-channel antagonists and low extracellular chloride concentrations, NEUROSCI L, 278(1-2), 2000, pp. 93-96
Histamine activates phospholipase C (PLC) in a number of cell-types includi
ng those of neuronal and neuroendocrine origin. We report here that Cl--cha
nnel antagonists of the niflumic acid-, but not stilbene disulphonic acid-c
lass, produced a concentration-dependent inhibition of histamine-stimulated
PLC activity in bovine adrenal medullary chromaffin cells. Low extracellul
ar [Cl-] (10 mM) produced a similar degree of inhibition. While the mechani
sm(s) responsible for this inhibition are not resolved it may be significan
t that low extracellular Cl- also reduced the magnitude of the histamine-in
duced Ca2+ signal. Thus, PLC inhibition may be secondary to a reduction in
Ca2+-inflow, a conclusion consistent with the known actions of niflumic aci
d-type compounds and the previously reported importance of Ca2+ influx in s
upporting histamine-stimulated PLC activity. (C) 2000 Elsevier Science Irel
and Ltd. All rights reserved.