Abstract
1. The role of membrane hyperpolarization on agonist-induced contraction was investigated in intact and alpha-toxin-skinned smooth muscles of rabbit mesenteric artery by use of the ATP-sensitive K+ channel opener, (-)-(3S,4R)-4-(N-acetyl-N-hydroxyamino)-6-cyano-3,4-dihydro-2,2- dimethyl-2H-1-benzopyran-3-ol (Y-26763), and either histamine (Hist) or noradrenaline (NA). 2. Hist (3 microM) and NA (10 microM) both produced a phasic, followed by a tonic increase in intracellular Ca2+ concentration ([Ca2+]i) and force. Y-26763 (10 microM) potently inhibited the NA-induced phasic and tonic increase in [Ca2+]i and force. In contrast, Y-26763 attenuated the Hist-induced phasic increase in [Ca2+]i and force but had almost no effect on the tonic response. However, ryanodine-treatment of muscles in order to inhibit the function of intracellular Ca2+ storage sites altered the action of Y-26763 which now attenuated the Hist-induced tonic increase in [Ca2+]i and force in a concentration-dependent manner (at concentrations > 1 microM). Glibenclamide (10 microM) attenuated the inhibitory action of Y-26763. 3. Hist (3 microM) depolarized the smooth muscle cells to the same extent as NA (10 microM). In the absence of either agonist, Y-26763 (over 30 nM) hyperpolarized the membrane and glibenclamide inhibited this hyperpolarization. Y-26763 (10 microM) almost abolished the NA-induced membrane depolarization, but only slightly attenuated the Hist-induced membrane depolarization in which the delta (delta) value (the difference before and after application of Hist) was not modified by any concentration of Y-26763. In ryanodine-treated smooth muscle cells, Y-26763 hyperpolarized the membrane and potently inhibited the membrane depolarization induced by Hist. 4. In ryanodine-treated muscle, Y-26763 had no measurable effect on the Hist-induced [Ca2+]i-force relationship. Y-26763 also had no apparent effect on the myofilament Ca(2+)-sensitivity in the presence of Hist in alpha-toxin-skinned smooth muscles. 5. It is concluded that the membrane hyperpolarization induced by Y-26763 may not be enough to inhibit the Hist-activated Ca2+ influx. It is also suggested that Hist prevents the membrane hyperpolarization induced by Y-26763, activating an unknown mechanism which is thought to depend on the function of intracellular Ca2+ storage sites.
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Selected References
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- Becker P. L., Singer J. J., Walsh J. V., Jr, Fay F. S. Regulation of calcium concentration in voltage-clamped smooth muscle cells. Science. 1989 Apr 14;244(4901):211–214. doi: 10.1126/science.2704996. [DOI] [PubMed] [Google Scholar]
- Bonev A. D., Nelson M. T. Muscarinic inhibition of ATP-sensitive K+ channels by protein kinase C in urinary bladder smooth muscle. Am J Physiol. 1993 Dec;265(6 Pt 1):C1723–C1728. doi: 10.1152/ajpcell.1993.265.6.C1723. [DOI] [PubMed] [Google Scholar]
- Fleischer S., Ogunbunmi E. M., Dixon M. C., Fleer E. A. Localization of Ca2+ release channels with ryanodine in junctional terminal cisternae of sarcoplasmic reticulum of fast skeletal muscle. Proc Natl Acad Sci U S A. 1985 Nov;82(21):7256–7259. doi: 10.1073/pnas.82.21.7256. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Grynkiewicz G., Poenie M., Tsien R. Y. A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem. 1985 Mar 25;260(6):3440–3450. [PubMed] [Google Scholar]
- Inoue R., Isenberg G. Intracellular calcium ions modulate acetylcholine-induced inward current in guinea-pig ileum. J Physiol. 1990 May;424:73–92. doi: 10.1113/jphysiol.1990.sp018056. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ito S., Kajikuri J., Itoh T., Kuriyama H. Effects of lemakalim on changes in Ca2+ concentration and mechanical activity induced by noradrenaline in the rabbit mesenteric artery. Br J Pharmacol. 1991 Sep;104(1):227–233. doi: 10.1111/j.1476-5381.1991.tb12411.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Itoh T., Ito S., Shafiq J., Suzuki H. Effects of a newly synthesized K+ channel opener, Y-26763, on noradrenaline-induced Ca2+ mobilization in smooth muscle of the rabbit mesenteric artery. Br J Pharmacol. 1994 Jan;111(1):165–172. doi: 10.1111/j.1476-5381.1994.tb14039.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Itoh T., Kajikuri J., Kuriyama H. Characteristic features of noradrenaline-induced Ca2+ mobilization and tension in arterial smooth muscle of the rabbit. J Physiol. 1992 Nov;457:297–314. doi: 10.1113/jphysiol.1992.sp019379. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Itoh T., Kanmura Y., Kuriyama H. Inorganic phosphate regulates the contraction-relaxation cycle in skinned muscles of the rabbit mesenteric artery. J Physiol. 1986 Jul;376:231–252. doi: 10.1113/jphysiol.1986.sp016151. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Itoh T., Kuriyama H., Suzuki H. Differences and similarities in the noradrenaline- and caffeine-induced mechanical responses in the rabbit mesenteric artery. J Physiol. 1983 Apr;337:609–629. doi: 10.1113/jphysiol.1983.sp014645. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Itoh T., Seki N., Suzuki S., Ito S., Kajikuri J., Kuriyama H. Membrane hyperpolarization inhibits agonist-induced synthesis of inositol 1,4,5-trisphosphate in rabbit mesenteric artery. J Physiol. 1992;451:307–328. doi: 10.1113/jphysiol.1992.sp019166. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kitazawa T., Gaylinn B. D., Denney G. H., Somlyo A. P. G-protein-mediated Ca2+ sensitization of smooth muscle contraction through myosin light chain phosphorylation. J Biol Chem. 1991 Jan 25;266(3):1708–1715. [PubMed] [Google Scholar]
- Nelson M. T., Standen N. B., Brayden J. E., Worley J. F., 3rd Noradrenaline contracts arteries by activating voltage-dependent calcium channels. Nature. 1988 Nov 24;336(6197):382–385. doi: 10.1038/336382a0. [DOI] [PubMed] [Google Scholar]
- Nishimura J., Kolber M., van Breemen C. Norepinephrine and GTP-gamma-S increase myofilament Ca2+ sensitivity in alpha-toxin permeabilized arterial smooth muscle. Biochem Biophys Res Commun. 1988 Dec 15;157(2):677–683. doi: 10.1016/s0006-291x(88)80303-6. [DOI] [PubMed] [Google Scholar]
- Poenie M., Alderton J., Steinhardt R., Tsien R. Calcium rises abruptly and briefly throughout the cell at the onset of anaphase. Science. 1986 Aug 22;233(4766):886–889. doi: 10.1126/science.3755550. [DOI] [PubMed] [Google Scholar]
- Quast U. Do the K+ channel openers relax smooth muscle by opening K+ channels? Trends Pharmacol Sci. 1993 Sep;14(9):332–337. doi: 10.1016/0165-6147(93)90006-6. [DOI] [PubMed] [Google Scholar]