Effects of genistein and herbimycin, tyrosine kinase inhibitors, on catecholamine release in bovine adrenal chromaffin cells
The effects of genistein and herbimycin, tyrosine kinase inhibitors, on catecholamine (CA) release were examined in bovine adrenal chromaffin cells.
In intact cells, genistein (10–100 μm) and herbimycin (3–30 μm) inhibited CA release induced by acetylcholine (ACh; 100 μm) or the nicotinic receptor stimulant 1,1-dimethyl-4-phenyl-piperazinium (DMPP; 10 μm), but did not affect CA release induced by high K+ (40 mm).
Genistein and herbimycin inhibited 45Ca2+ uptake induced by ACh (100 μm).
Neither genistein nor herbimycin affected [3H]nicotine binding with nicotinic receptors.
In β-escin-permeabilized cells, neither genistein nor herbimycin affected CA release induced by Ca2+ (1 μm).
These results suggest that protein tyrosine kinase plays the facilitatory role in the regulation of CA release induced by nicotinic receptor stimulation in stimulus-secretion coupling of bovine adrenal chromaffin cells.