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. 1991 May;103(1):1033–1040. doi: 10.1111/j.1476-5381.1991.tb12296.x

The diverse effects of cromakalim on tension and 86Rb efflux in canine arterial smooth muscle.

K Masuzawa 1, T Matsuda 1, M Asano 1
PMCID: PMC1908079  PMID: 1878743

Abstract

1. To characterize further the K+ channels opened by cromakalim in arterial smooth muscle, the effects of cromakalim on tension and 86Rb efflux were compared in endothelium-denuded strips of coronary, mesenteric and middle cerebral (MC) arteries of the dog. 2. Cromakalim relaxed strips precontracted with 20.9 mM K+. The maximum relaxation induced by cromakalim varied in the arteries used; 94% in the coronary artery, 60% in the mesenteric artery and only 38% in the MC artery. Cromakalim failed to relax arterial strips precontracted with 65.9 mM K+. 3. When the effects of cromakalim on 86Rb efflux were determined in 20.9 mM K(+)-contracted strips, cromakalim-induced relaxations were accompanied by a large increase in 86Rb efflux in the coronary artery, by a small increase in the mesenteric artery but by an apparent decrease in the MC artery. 4. When 10(-7) M nifedipine was added to 20.9 mM K(+)-contracted strips, to inactivate Ca2(+)-activated K+ (KCa) channels, cromakalim produced a greater increase (measured from the point at which cromakalim was administered) in 86Rb efflux than in the absence of nifedipine, suggesting that the effects of cromakalim on 86Rb efflux from the 20.9 mM K(+)-contracted strips may be the resultant of two opposing effects: an increased 86Rb efflux perhaps due to the opening of ATP-sensitive K+ (KATP) channels, and a decreased efflux due to the closing of KCa channels.(ABSTRACT TRUNCATED AT 250 WORDS)

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Selected References

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  1. ARUNLAKSHANA O., SCHILD H. O. Some quantitative uses of drug antagonists. Br J Pharmacol Chemother. 1959 Mar;14(1):48–58. doi: 10.1111/j.1476-5381.1959.tb00928.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Aaronson P. I., Jones A. W. Calcium regulation of potassium fluxes in rabbit aorta during activation by noradrenaline or high potassium medium. J Physiol. 1985 Oct;367:27–43. doi: 10.1113/jphysiol.1985.sp015812. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Asano M., Aoki K., Suzuki Y., Matsuda T. Effects of Bay k 8644 and nifedipine on isolated dog cerebral, coronary and mesenteric arteries. J Pharmacol Exp Ther. 1987 Nov;243(2):646–656. [PubMed] [Google Scholar]
  4. Asano M., Masuzawa K., Matsuda T. Evidence for reduced beta-adrenoceptor coupling to adenylate cyclase in femoral arteries from spontaneously hypertensive rats. Br J Pharmacol. 1988 May;94(1):73–86. doi: 10.1111/j.1476-5381.1988.tb11501.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Bolton T. B., Clapp L. H. The diverse effects of noradrenaline and other stimulants on 86Rb and 42K efflux in rabbit and guinea-pig arterial muscle. J Physiol. 1984 Oct;355:43–63. doi: 10.1113/jphysiol.1984.sp015405. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Buckingham R. E., Hamilton T. C., Howlett D. R., Mootoo S., Wilson C. Inhibition by glibenclamide of the vasorelaxant action of cromakalim in the rat. Br J Pharmacol. 1989 May;97(1):57–64. doi: 10.1111/j.1476-5381.1989.tb11923.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Casteels R., Droogmans G. Dependence on calcium of potassium- and agonist-induced changes in potassium permeability of rabbit ear artery. J Physiol. 1985 Jul;364:151–167. doi: 10.1113/jphysiol.1985.sp015736. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Cavero I., Mondot S., Mestre M. Vasorelaxant effects of cromakalim in rats are mediated by glibenclamide-sensitive potassium channels. J Pharmacol Exp Ther. 1989 Mar;248(3):1261–1268. [PubMed] [Google Scholar]
  9. Cook N. S., Quast U., Hof R. P., Baumlin Y., Pally C. Similarities in the mechanism of action of two new vasodilator drugs: pinacidil and BRL 34915. J Cardiovasc Pharmacol. 1988 Jan;11(1):90–99. doi: 10.1097/00005344-198801000-00014. [DOI] [PubMed] [Google Scholar]
  10. Cook N. S., Weir S. W., Danzeisen M. C. Anti-vasoconstrictor effects of the K+ channel opener cromakalim on the rabbit aorta--comparison with the calcium antagonist isradipine. Br J Pharmacol. 1988 Nov;95(3):741–752. doi: 10.1111/j.1476-5381.1988.tb11700.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Hamilton T. C., Weir S. W., Weston A. H. Comparison of the effects of BRL 34915 and verapamil on electrical and mechanical activity in rat portal vein. Br J Pharmacol. 1986 May;88(1):103–111. doi: 10.1111/j.1476-5381.1986.tb09476.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Hamilton T. C., Weston A. H. Cromakalim, nicorandil and pinacidil: novel drugs which open potassium channels in smooth muscle. Gen Pharmacol. 1989;20(1):1–9. doi: 10.1016/0306-3623(89)90052-9. [DOI] [PubMed] [Google Scholar]
  13. Imaizumi Y., Watanabe M. The effect of tetraethylammonium chloride on potassium permeability in the smooth muscle cell membrane of canine trachea. J Physiol. 1981 Jul;316:33–46. doi: 10.1113/jphysiol.1981.sp013770. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Masuzawa K., Asano M., Matsuda T., Imaizumi Y., Watanabe M. Comparison of effects of cromakalim and pinacidil on mechanical activity and 86Rb efflux in dog coronary arteries. J Pharmacol Exp Ther. 1990 May;253(2):586–593. [PubMed] [Google Scholar]
  15. Masuzawa K., Matsuda T., Asano M. Evidence that pinacidil may promote the opening of ATP-sensitive K+ channels yet inhibit the opening of Ca2(+)-activated K+ channels in K(+)-contracted canine mesenteric artery. Br J Pharmacol. 1990 May;100(1):143–149. doi: 10.1111/j.1476-5381.1990.tb12066.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Quast U., Baumlin Y. Comparison of the effluxes of 42K+ and 86Rb+ elicited by cromakalim (BRL 34915) in tonic and phasic vascular tissue. Naunyn Schmiedebergs Arch Pharmacol. 1988 Sep;338(3):319–326. doi: 10.1007/BF00173407. [DOI] [PubMed] [Google Scholar]
  17. Quast U., Cook N. S. In vitro and in vivo comparison of two K+ channel openers, diazoxide and cromakalim, and their inhibition by glibenclamide. J Pharmacol Exp Ther. 1989 Jul;250(1):261–271. [PubMed] [Google Scholar]
  18. Quast U. Effect of the K+ efflux stimulating vasodilator BRL 34915 on 86Rb+ efflux and spontaneous activity in guinea-pig portal vein. Br J Pharmacol. 1987 Jul;91(3):569–578. doi: 10.1111/j.1476-5381.1987.tb11250.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Smith J. M., Sanchez A. A., Jones A. W. Comparison of rubidium-86 and potassium-42 fluxes in rat aorta. Blood Vessels. 1986;23(6):297–309. doi: 10.1159/000158657. [DOI] [PubMed] [Google Scholar]
  20. Standen N. B., Quayle J. M., Davies N. W., Brayden J. E., Huang Y., Nelson M. T. Hyperpolarizing vasodilators activate ATP-sensitive K+ channels in arterial smooth muscle. Science. 1989 Jul 14;245(4914):177–180. doi: 10.1126/science.2501869. [DOI] [PubMed] [Google Scholar]
  21. Su C., Bevan J. A. The release of H3-norepinephrine in arterial strips studied by the technique of superfusion and transmural stimulation. J Pharmacol Exp Ther. 1970 Mar;172(1):62–68. [PubMed] [Google Scholar]
  22. Weir S. W., Weston A. H. The effects of BRL 34915 and nicorandil on electrical and mechanical activity and on 86Rb efflux in rat blood vessels. Br J Pharmacol. 1986 May;88(1):121–128. doi: 10.1111/j.1476-5381.1986.tb09478.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Wilson C. Inhibition by sulphonylureas of vasorelaxation induced by K+ channel activators in vitro. J Auton Pharmacol. 1989 Feb;9(1):71–78. doi: 10.1111/j.1474-8673.1989.tb00198.x. [DOI] [PubMed] [Google Scholar]
  24. Winquist R. J., Heaney L. A., Wallace A. A., Baskin E. P., Stein R. B., Garcia M. L., Kaczorowski G. J. Glyburide blocks the relaxation response to BRL 34915 (cromakalim), minoxidil sulfate and diazoxide in vascular smooth muscle. J Pharmacol Exp Ther. 1989 Jan;248(1):149–156. [PubMed] [Google Scholar]

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