Abstract
1. Single-channel recordings were made from cell-attached and isolated patches, and whole-cell currents were recorded under voltage clamp from single smooth muscle cells obtained by enzymic digestion of a small branch of the rat mesenteric artery. 2. In single voltage-clamped cells 1 mM uridine diphosphate (UDP) or guanidine diphosphate (GDP) added to the pipette solution, or pinacidil (100 microM) a K-channel opener (KCO) applied in the bathing solution, evoked an outward current of up to 100pA which was blocked by glibenclamide (10 microM). In single cells from which recordings were made by the 'perforated patch' (nystatin pipette) technique, metabolic inhibition by 1 mM NaCN and 10 mM 2-deoxy-glucose also evoked a similar glibenclamide-sensitive current. 3. Single K-channel activity was observed in cell-attached patches only infrequently unless the metabolism of the cell was inhibited, whereupon channel activity blocked by glibenclamide was seen; pinacidil applied to the cell evoked similar glibenclamide-sensitive channel activity. If the patch was pulled off the cell to form an isolated inside-out patch, similar glibenclamide-sensitive single-channel currents were observed in the presence of UDP and/or pinacidil to those seen in cell-attached mode; channel conductance was 20 pS (60:130 K-gradient) and openings showed no voltage-dependence and noisy inward currents, typical of the nucleoside diphosphate (NDP) activated K-channel (KNDP) seen previously in rabbit portal vein. 4. Formation of an isolated inside-out patch into an ATP-free solution did not increase the probability of channel opening which declined with time even when some single-channel activity had occurred in the cell-attached mode before detachment. However, application of 1 mM UDP or GDP, but not ATP, to inside-out patches evoked single-channel activity. Application of ATP-free solution to isolated patches, previously exposed to ATP and in which channel activity had been seen, did not evoke channel activity. 5. It is concluded that small conductance K-channels (KNDP) open in smooth muscle cells from this small artery in response to UDP or GDP acting from the inside, or pinacidil acting from the outside; the same channels open during inhibition of metabolism presumably mainly due to the rise in nucleoside diphosphates, but a fall in the ATP concentration on the inside of the channel did not by itself evoke channel activity.(ABSTRACT TRUNCATED AT 400 WORDS)
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Selected References
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- Ashford M. L., Bond C. T., Blair T. A., Adelman J. P. Cloning and functional expression of a rat heart KATP channel. Nature. 1994 Aug 11;370(6489):456–459. doi: 10.1038/370456a0. [DOI] [PubMed] [Google Scholar]
- Beech D. J., Bolton T. B. Properties of the cromakalim-induced potassium conductance in smooth muscle cells isolated from the rabbit portal vein. Br J Pharmacol. 1989 Nov;98(3):851–864. doi: 10.1111/j.1476-5381.1989.tb14614.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Beech D. J., Zhang H., Nakao K., Bolton T. B. K channel activation by nucleotide diphosphates and its inhibition by glibenclamide in vascular smooth muscle cells. Br J Pharmacol. 1993 Oct;110(2):573–582. doi: 10.1111/j.1476-5381.1993.tb13849.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Beech D. J., Zhang H., Nakao K., Bolton T. B. Single channel and whole-cell K-currents evoked by levcromakalim in smooth muscle cells from the rabbit portal vein. Br J Pharmacol. 1993 Oct;110(2):583–590. doi: 10.1111/j.1476-5381.1993.tb13850.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bonev A. D., Nelson M. T. ATP-sensitive potassium channels in smooth muscle cells from guinea pig urinary bladder. Am J Physiol. 1993 May;264(5 Pt 1):C1190–C1200. doi: 10.1152/ajpcell.1993.264.5.C1190. [DOI] [PubMed] [Google Scholar]
- Brayden J. E., Nelson M. T. Regulation of arterial tone by activation of calcium-dependent potassium channels. Science. 1992 Apr 24;256(5056):532–535. doi: 10.1126/science.1373909. [DOI] [PubMed] [Google Scholar]
- Carl A., Bowen S., Gelband C. H., Sanders K. M., Hume J. R. Cromakalim and lemakalim activate Ca(2+)-dependent K+ channels in canine colon. Pflugers Arch. 1992 May;421(1):67–76. doi: 10.1007/BF00374735. [DOI] [PubMed] [Google Scholar]
- Clapp L. H., Gurney A. M., Standen N. B., Langton P. D. Properties of the ATP-sensitive K+ current activated by levcromakalim in isolated pulmonary arterial myocytes. J Membr Biol. 1994 Jun;140(3):205–213. doi: 10.1007/BF00233709. [DOI] [PubMed] [Google Scholar]
- Cook D. L., Hales C. N. Intracellular ATP directly blocks K+ channels in pancreatic B-cells. Nature. 1984 Sep 20;311(5983):271–273. doi: 10.1038/311271a0. [DOI] [PubMed] [Google Scholar]
- Criddle D. N., Greenwood I. A., Weston A. H. Levcromakalim-induced modulation of membrane potassium currents, intracellular calcium and mechanical activity in rat mesenteric artery. Naunyn Schmiedebergs Arch Pharmacol. 1994 Apr;349(4):422–430. doi: 10.1007/BF00170890. [DOI] [PubMed] [Google Scholar]
- Daut J., Maier-Rudolph W., von Beckerath N., Mehrke G., Günther K., Goedel-Meinen L. Hypoxic dilation of coronary arteries is mediated by ATP-sensitive potassium channels. Science. 1990 Mar 16;247(4948):1341–1344. doi: 10.1126/science.2107575. [DOI] [PubMed] [Google Scholar]
- Dunne M. J., Aspinall R. J., Petersen O. H. The effects of cromakalim on ATP-sensitive potassium channels in insulin-secreting cells. Br J Pharmacol. 1990 Jan;99(1):169–175. doi: 10.1111/j.1476-5381.1990.tb14672.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dunne M. J. Effects of pinacidil, RP 49356 and nicorandil on ATP-sensitive potassium channels in insulin-secreting cells. Br J Pharmacol. 1990 Mar;99(3):487–492. doi: 10.1111/j.1476-5381.1990.tb12955.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dunne M. J., Yule D. I., Gallacher D. V., Petersen O. H. Comparative study of the effects of cromakalim (BRL 34915) and diazoxide on membrane potential, [Ca2+]i and ATP-sensitive potassium currents in insulin-secreting cells. J Membr Biol. 1990 Mar;114(1):53–60. doi: 10.1007/BF01869384. [DOI] [PubMed] [Google Scholar]
- Edwards G., Ibbotson T., Weston A. H. Levcromakalim may induce a voltage-independent K-current in rat portal veins by modifying the gating properties of the delayed rectifier. Br J Pharmacol. 1993 Nov;110(3):1037–1048. doi: 10.1111/j.1476-5381.1993.tb13918.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Findlay I. ATP-sensitive K+ channels in rat ventricular myocytes are blocked and inactivated by internal divalent cations. Pflugers Arch. 1987 Oct;410(3):313–320. doi: 10.1007/BF00580282. [DOI] [PubMed] [Google Scholar]
- Findlay I., Dunne M. J. ATP maintains ATP-inhibited K+ channels in an operational state. Pflugers Arch. 1986 Aug;407(2):238–240. doi: 10.1007/BF00580683. [DOI] [PubMed] [Google Scholar]
- Fujii K., Foster C. D., Brading A. F., Parekh A. B. Potassium channel blockers and the effects of cromakalim on the smooth muscle of the guinea-pig bladder. Br J Pharmacol. 1990 Apr;99(4):779–785. doi: 10.1111/j.1476-5381.1990.tb13006.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Grant T. L., Zuzack J. S. Effects of K+ channel blockers and cromakalim (BRL 34915) on the mechanical activity of guinea pig detrusor smooth muscle. J Pharmacol Exp Ther. 1991 Dec;259(3):1158–1164. [PubMed] [Google Scholar]
- Hamill O. P., Marty A., Neher E., Sakmann B., Sigworth F. J. Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflugers Arch. 1981 Aug;391(2):85–100. doi: 10.1007/BF00656997. [DOI] [PubMed] [Google Scholar]
- Horn R., Marty A. Muscarinic activation of ionic currents measured by a new whole-cell recording method. J Gen Physiol. 1988 Aug;92(2):145–159. doi: 10.1085/jgp.92.2.145. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Inoue I., Nakaya Y., Nakaya S., Mori H. Extracellular Ca2+-activated K channel in coronary artery smooth muscle cells and its role in vasodilation. FEBS Lett. 1989 Sep 25;255(2):281–284. doi: 10.1016/0014-5793(89)81106-8. [DOI] [PubMed] [Google Scholar]
- Kajioka S., Kitamura K., Kuriyama H. Guanosine diphosphate activates an adenosine 5'-triphosphate-sensitive K+ channel in the rabbit portal vein. J Physiol. 1991 Dec;444:397–418. doi: 10.1113/jphysiol.1991.sp018885. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kajioka S., Oike M., Kitamura K. Nicorandil opens a calcium-dependent potassium channel in smooth muscle cells of the rat portal vein. J Pharmacol Exp Ther. 1990 Sep;254(3):905–913. [PubMed] [Google Scholar]
- Kakei M., Noma A., Shibasaki T. Properties of adenosine-triphosphate-regulated potassium channels in guinea-pig ventricular cells. J Physiol. 1985 Jun;363:441–462. doi: 10.1113/jphysiol.1985.sp015721. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Klöckner U., Trieschmann U., Isenberg G. Pharmacological modulation of calcium and potassium channels in isolated vascular smooth muscle cells. Arzneimittelforschung. 1989 Jan;39(1A):120–126. [PubMed] [Google Scholar]
- Kovacs R. J., Nelson M. T. ATP-sensitive K+ channels from aortic smooth muscle incorporated into planar lipid bilayers. Am J Physiol. 1991 Aug;261(2 Pt 2):H604–H609. doi: 10.1152/ajpheart.1991.261.2.H604. [DOI] [PubMed] [Google Scholar]
- Lederer W. J., Nichols C. G. Nucleotide modulation of the activity of rat heart ATP-sensitive K+ channels in isolated membrane patches. J Physiol. 1989 Dec;419:193–211. doi: 10.1113/jphysiol.1989.sp017869. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lorenz J. N., Schnermann J., Brosius F. C., Briggs J. P., Furspan P. B. Intracellular ATP can regulate afferent arteriolar tone via ATP-sensitive K+ channels in the rabbit. J Clin Invest. 1992 Sep;90(3):733–740. doi: 10.1172/JCI115945. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Misler S., Falke L. C., Gillis K., McDaniel M. L. A metabolite-regulated potassium channel in rat pancreatic B cells. Proc Natl Acad Sci U S A. 1986 Sep;83(18):7119–7123. doi: 10.1073/pnas.83.18.7119. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miyoshi H., Nakaya Y. Activation of ATP-sensitive K+ channels by cyclic AMP-dependent protein kinase in cultured smooth muscle cells of porcine coronary artery. Biochem Biophys Res Commun. 1993 May 28;193(1):240–247. doi: 10.1006/bbrc.1993.1615. [DOI] [PubMed] [Google Scholar]
- Miyoshi Y., Nakaya Y., Wakatsuki T., Nakaya S., Fujino K., Saito K., Inoue I. Endothelin blocks ATP-sensitive K+ channels and depolarizes smooth muscle cells of porcine coronary artery. Circ Res. 1992 Mar;70(3):612–616. doi: 10.1161/01.res.70.3.612. [DOI] [PubMed] [Google Scholar]
- Nelson M. T., Patlak J. B., Worley J. F., Standen N. B. Calcium channels, potassium channels, and voltage dependence of arterial smooth muscle tone. Am J Physiol. 1990 Jul;259(1 Pt 1):C3–18. doi: 10.1152/ajpcell.1990.259.1.C3. [DOI] [PubMed] [Google Scholar]
- Noack T., Deitmer P., Edwards G., Weston A. H. Characterization of potassium currents modulated by BRL 38227 in rat portal vein. Br J Pharmacol. 1992 Jul;106(3):717–726. doi: 10.1111/j.1476-5381.1992.tb14400.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Noack T., Edwards G., Deitmer P., Weston A. H. Potassium channel modulation in rat portal vein by ATP depletion: a comparison with the effects of levcromakalim (BRL 38227). Br J Pharmacol. 1992 Dec;107(4):945–955. doi: 10.1111/j.1476-5381.1992.tb13390.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Noma A. ATP-regulated K+ channels in cardiac muscle. Nature. 1983 Sep 8;305(5930):147–148. doi: 10.1038/305147a0. [DOI] [PubMed] [Google Scholar]
- Ohno-Shosaku T., Zünkler B. J., Trube G. Dual effects of ATP on K+ currents of mouse pancreatic beta-cells. Pflugers Arch. 1987 Feb;408(2):133–138. doi: 10.1007/BF00581342. [DOI] [PubMed] [Google Scholar]
- Robertson B. E., Corry P. R., Nye P. C., Kozlowski R. Z. Ca2+ and Mg-ATP activated potassium channels from rat pulmonary artery. Pflugers Arch. 1992 Jun;421(2-3):94–96. [PubMed] [Google Scholar]
- Rorsman P., Trube G. Glucose dependent K+-channels in pancreatic beta-cells are regulated by intracellular ATP. Pflugers Arch. 1985 Dec;405(4):305–309. doi: 10.1007/BF00595682. [DOI] [PubMed] [Google Scholar]
- Shen W. K., Tung R. T., Machulda M. M., Kurachi Y. Essential role of nucleotide diphosphates in nicorandil-mediated activation of cardiac ATP-sensitive K+ channel. A comparison with pinacidil and lemakalim. Circ Res. 1991 Oct;69(4):1152–1158. doi: 10.1161/01.res.69.4.1152. [DOI] [PubMed] [Google Scholar]
- Silberberg S. D., van Breemen C. A potassium current activated by lemakalim and metabolic inhibition in rabbit mesenteric artery. Pflugers Arch. 1992 Jan;420(1):118–120. doi: 10.1007/BF00378653. [DOI] [PubMed] [Google Scholar]
- 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]
- Takano M., Qin D. Y., Noma A. ATP-dependent decay and recovery of K+ channels in guinea pig cardiac myocytes. Am J Physiol. 1990 Jan;258(1 Pt 2):H45–H50. doi: 10.1152/ajpheart.1990.258.1.H45. [DOI] [PubMed] [Google Scholar]
- Terzic A., Tung R. T., Kurachi Y. Nucleotide regulation of ATP sensitive potassium channels. Cardiovasc Res. 1994 Jun;28(6):746–753. doi: 10.1093/cvr/28.6.746. [DOI] [PubMed] [Google Scholar]
- Trube G., Hescheler J. Inward-rectifying channels in isolated patches of the heart cell membrane: ATP-dependence and comparison with cell-attached patches. Pflugers Arch. 1984 Jun;401(2):178–184. doi: 10.1007/BF00583879. [DOI] [PubMed] [Google Scholar]
- Tung R. T., Kurachi Y. On the mechanism of nucleotide diphosphate activation of the ATP-sensitive K+ channel in ventricular cell of guinea-pig. J Physiol. 1991 Jun;437:239–256. doi: 10.1113/jphysiol.1991.sp018593. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wakatsuki T., Nakaya Y., Inoue I. Vasopressin modulates K(+)-channel activities of cultured smooth muscle cells from porcine coronary artery. Am J Physiol. 1992 Aug;263(2 Pt 2):H491–H496. doi: 10.1152/ajpheart.1992.263.2.H491. [DOI] [PubMed] [Google Scholar]
- 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]