+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Effects of the potassium channel openers cromakalim and pinacidil on catecholamine secretion and calcium mobilization in cultured bovine adrenal chromaffin cells



Effects of the potassium channel openers cromakalim and pinacidil on catecholamine secretion and calcium mobilization in cultured bovine adrenal chromaffin cells



Biochemical Pharmacology 47(10): 1751-1758



The effects of two K+ channel openers, cromakalim and pinacidil, on voltage-dependent and receptor-mediated catecholamine secretion and Ca-2+ mobilization in bovine adrenal chromaffin cells were studied to determine the role of membrane K+ channels in the regulation of a Ca-2+-dependent secretory process. Both cromakalim and pinacidil stimulated the efflux of 86Rb (used to monitor K+ permeability) from preloaded cells. Cromakalim and pinacidil did not affect the catecholamine secretion induced by excessive depolarization with 56 mM K+, but inhibited that induced by moderate depolarization with 31 mM K+ in a concentration-dependent manner (1 mu-M-100 mu-M). The 31 mM K+-induced 45Ca-2+ influx and increase in intracellular free Ca-2+ concentration (Ca-2+)i were also inhibited by these agents at similar concentrations to those for inhibition of catecholamine secretion. Cromakalim and pinacidil inhibited catecholamine secretion, 45Ca-2+ influx and increase in (Ca-2+)i induced by stimulation of nicotinic acetylcholine (ACh) receptors with carbamylcholine. Furthermore, both cromakalim and pinacidil inhibited the increase in (Ca-2+)i induced by carbamylcholine in the absence of extracellular Ca-2+, which is thought to be mediated by muscarinic ACh receptors. On the other hand, they did not affect catecholamine secretion induced by Bay-K 8644, Ba-2+, A23187, histamine or bradykinin. These results indicate that the K+ channel openers, cromakalim and pinacidil, selectively inhibit catecholamine secretion induced by moderate depolarization or by nicotinic ACh receptor stimulation by inhibiting Ca-2+ influx and increase in (Ca-2+)i. Furthermore, the results suggest that these K+ channel openers-sensitive membrane K+ channels are involved in the regulation of catecholamine secretion mainly indirectly through effects on the voltage-dependent membrane Ca-2+ channels.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 008584193

Download citation: RISBibTeXText

PMID: 7515621

DOI: 10.1016/0006-2952(94)90302-6


Related references

Effects of potassium channel openers on catecholamine secretion and calcium mobilization in cultured bovine adrenal chromaffin cells. Japanese Journal of Pharmacology 61(Suppl. 1): 77P, 1993

Effects of potassium channel openers on catecholamine secretion and Ca-2+ mobilization in cultured bovine adrenal chromaffin cells. Society for Neuroscience Abstracts 19(1-3): 1337, 1993

Effects of potassium channel openers on catecholamine secretion from cultured bovine adrenal chromaffin cells. Japanese Journal of Pharmacology 59(Suppl. 1): 96P, 1992

Effects of nitroprusside and nicorandil on catecholamine secretion and calcium mobilization in cultured bovine adrenal chromaffin cells. Journal of Cardiovascular Pharmacology 30(4): 419-423, 1997

Effects of calcium channel blockers on catecholamine secretion from cultured bovine adrenal chromaffin cells. Japanese Journal of Pharmacology 73(Suppl. 1): 159P, 1997

Characterization of palytoxin induced catecholamine secretion from cultured bovine adrenal chromaffin cells effects of sodium channel and calcium channel blockers. Biochemical Pharmacology 42(1): 17-24, 1991

Effects of histamine and potassium channel blockers on catecholamine formation in cultured bovine adrenal chromaffin cells. Japanese Journal of Pharmacology 67(Suppl. 1): 251P, 1995

Characterization of palytoxin-induced catecholamine secretion from cultured bovine adrenal chromaffin cells. Effects of Na(+)- and Ca(2+)-channel blockers. Biochemical Pharmacology 42(1): 17-23, 1991

Effects of sodium/calcium exchanger inhibitors on catecholamine secretion from cultured bovine adrenal chromaffin cells. Journal of Neurochemistry 87(Suppl. 1): 46, 2003

Effects of hypoglycemic sulfonylureas on catecholamine secretion and calcium uptake in cultured bovine adrenal chromaffin cells. Biochemical Pharmacology 37(5): 983-985, 1988

Comparative effects of the potassium channel openers cromakalim and pinacidil and the cromakalim analog U-89232 on isolated vascular and cardiac tissue. Pharmacology 49(2): 86-95, 1994

Ryanodine inhibits caffeine-evoked Ca2+ mobilization and catecholamine secretion from cultured bovine adrenal chromaffin cells. Journal of Neurochemistry 57(6): 1884-1890, 1991

Comparative effects of the potassium channel openers cromakalim pinacidil and nicorandil on cytosolic calcium levels and contraction in vascular smooth muscle. Japanese Journal of Pharmacology 52(Suppl. 1): 36P, 1990

Cardiohemodynamic effects of cromakalim and pinacidil potassium channel openers. Japanese Journal of Pharmacology 49(Suppl.): 58P, 1989

Regulation by SK type K channel of histamine-and bradykinin-induced catecholamine secretion from cultured bovine adrenal chromaffin cells. Japanese Journal of Pharmacology 64(Suppl. 1): 171P, 1994