Abstract
1. The effect of the inhibition of oxidative phosphorylation on intracellular calcium concentration ([Ca2+]i), phosphorylation of the 20 kDa regulatory light chain of myosin (MLC20) and contractility was investigated in isolated longitudinal smooth muscle from rat uteri. 2. Cyanide (2 mM) application to normally polarized preparations resulted in an elevation of basal [Ca2+]i but an inhibition of [Ca2+]i transients and the accompanying contractions. 3. Depolarization with high-K+ solution (40 mM KCI) resulted in elevation of [Ca2+]i and maintained force production. Phosphorylation of MLC20 was transiently increased followed by a steady-state augmentation above resting levels. 4. Carbachol (100 microM) produced a transient elevation of [Ca2+]i and force of depolarized tissues followed by a steady-state augmentation of both parameters. PGF2 alpha (1 microM) did not significantly potentiate [Ca2+]i or force in depolarized preparations. Both carbachol and PGF2 alpha potentiated phosphorylation of MLC20 in depolarized tissues. 5. Addition of cyanide to depolarized preparations, in the presence or absence of carbachol or PGF2 alpha, resulted in significant attenuation of force under each condition. The magnitude and normalized rates of force inhibition by cyanide were not significantly different for each stimulus condition. MLC20 phosphorylation levels were unaltered by cyanide treatment. However, cyanide increased the maintained level of [Ca2+]i under each experimental protocol. 6. It is concluded that the inhibition of oxidative phosphorylation with cyanide results in dissociation of both the [Ca2+]i-force and MLC20 phosphorylation-force relationships in rat uterine smooth muscle.
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Selected References
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- Aalkjaer C., Lombard J. H. Effect of hypoxia on force, intracellular pH and Ca2+ concentration in rat cerebral and mesenteric small arteries. J Physiol. 1995 Jan 15;482(Pt 2):409–419. doi: 10.1113/jphysiol.1995.sp020528. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Adelstein R. S., Klee C. B. Purification and characterization of smooth muscle myosin light chain kinase. J Biol Chem. 1981 Jul 25;256(14):7501–7509. [PubMed] [Google Scholar]
- Arner A., Hellstrand P. Effects of calcium and substrate on force-velocity relation and energy turnover in skinned smooth muscle of the guinea-pig. J Physiol. 1985 Mar;360:347–365. doi: 10.1113/jphysiol.1985.sp015621. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Austin C., Wray S. The effects of extracellular pH and calcium change on force and intracellular calcium in rat vascular smooth muscle. J Physiol. 1995 Oct 15;488(Pt 2):281–291. doi: 10.1113/jphysiol.1995.sp020966. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Burdyga V., Kosterin S. A. Kinetic analysis of smooth muscle relaxation. Gen Physiol Biophys. 1991 Dec;10(6):589–598. [PubMed] [Google Scholar]
- Carafoli E. The Ca2+ pump of the plasma membrane. J Biol Chem. 1992 Feb 5;267(4):2115–2118. [PubMed] [Google Scholar]
- Clark J. F., Khuchua Z., Kuznetsov A., Saks V. A., Ventura-Clapier R. Compartmentation of creatine kinase isoenzymes in myometrium of gravid guinea-pig. J Physiol. 1993 Jul;466:553–572. [PMC free article] [PubMed] [Google Scholar]
- Crichton C. A., Taggart M. J., Wray S., Smith G. L. Effects of pH and inorganic phosphate on force production in alpha-toxin-permeabilized isolated rat uterine smooth muscle. J Physiol. 1993 Jun;465:629–645. doi: 10.1113/jphysiol.1993.sp019697. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dart C., Standen N. B. Activation of ATP-dependent K+ channels by hypoxia in smooth muscle cells isolated from the pig coronary artery. J Physiol. 1995 Feb 15;483(Pt 1):29–39. doi: 10.1113/jphysiol.1995.sp020565. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Drummond R. M., Fay F. S. Mitochondria contribute to Ca2+ removal in smooth muscle cells. Pflugers Arch. 1996 Feb;431(4):473–482. doi: 10.1007/BF02191893. [DOI] [PubMed] [Google Scholar]
- Ekmehag B. L., Hellstrand P. Contractile and metabolic characteristics of creatine-depleted vascular smooth muscle of the rat portal vein. Acta Physiol Scand. 1988 Aug;133(4):525–533. doi: 10.1111/j.1748-1716.1988.tb08437.x. [DOI] [PubMed] [Google Scholar]
- Eng J., Lynch R. M., Balaban R. S. Nicotinamide adenine dinucleotide fluorescence spectroscopy and imaging of isolated cardiac myocytes. Biophys J. 1989 Apr;55(4):621–630. doi: 10.1016/S0006-3495(89)82859-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FILO R. S., BOHR D. F., RUEGG J. C. GLYCERINATED SKELETAL AND SMOOTH MUSCLE: CALCIUM AND MAGNESIUM DEPENDENCE. Science. 1965 Mar 26;147(3665):1581–1583. doi: 10.1126/science.147.3665.1581. [DOI] [PubMed] [Google Scholar]
- Gagelmann M., Güth K. Effect of inorganic phosphate on the Ca2+ sensitivity in skinned Taenia coli smooth muscle fibers. Comparison of tension, ATPase activity, and phosphorylation of the regulatory myosin light chains. Biophys J. 1987 Mar;51(3):457–463. doi: 10.1016/S0006-3495(87)83367-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gao W. D., Liu Y., Mellgren R., Marban E. Intrinsic myofilament alterations underlying the decreased contractility of stunned myocardium. A consequence of Ca2+-dependent proteolysis? Circ Res. 1996 Mar;78(3):455–465. doi: 10.1161/01.res.78.3.455. [DOI] [PubMed] [Google Scholar]
- Haeberle J. R., Hott J. W., Hathaway D. R. Regulation of isometric force and isotonic shortening velocity by phosphorylation of the 20,000 dalton myosin light chain of rat uterine smooth muscle. Pflugers Arch. 1985 Feb;403(2):215–219. doi: 10.1007/BF00584103. [DOI] [PubMed] [Google Scholar]
- Hardin C. D., Wiseman R. W., Kushmerick M. J. Tension responses of sheep aorta to simultaneous decreases in phosphocreatine, inorganic phosphate and ATP. J Physiol. 1992 Dec;458:139–150. doi: 10.1113/jphysiol.1992.sp019410. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harrison N., Larcombe-McDouall J. B., Earley L., Wray S. An in vivo study of the effects of ischaemia on uterine contraction, intracellular pH and metabolites in the rat. J Physiol. 1994 Apr 15;476(2):349–354. doi: 10.1113/jphysiol.1994.sp020136. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heaton R. C., Wray S., Eisner D. A. Effects of metabolic inhibition and changes of intracellular pH on potassium permeability and contraction of rat uterus. J Physiol. 1993 Jun;465:43–56. doi: 10.1113/jphysiol.1993.sp019665. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Himpens B., Somlyo A. P. Free-calcium and force transients during depolarization and pharmacomechanical coupling in guinea-pig smooth muscle. J Physiol. 1988 Jan;395:507–530. doi: 10.1113/jphysiol.1988.sp016932. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Huang S. M., Chowdhury J. U., Kobayashi K., Tomita T. Inhibitory effects of cyanide on mechanical and electrical activities in the circular muscle of gastric antrum of guinea-pig stomach. Jpn J Physiol. 1993;43(2):229–238. doi: 10.2170/jjphysiol.43.229. [DOI] [PubMed] [Google Scholar]
- Iino M. Tension responses of chemically skinned fibre bundles of the guinea-pig taenia caeci under varied ionic environments. J Physiol. 1981 Nov;320:449–467. doi: 10.1113/jphysiol.1981.sp013961. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Khromov A., Somlyo A. V., Trentham D. R., Zimmermann B., Somlyo A. P. The role of MgADP in force maintenance by dephosphorylated cross-bridges in smooth muscle: a flash photolysis study. Biophys J. 1995 Dec;69(6):2611–2622. doi: 10.1016/S0006-3495(95)80132-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kitazawa T., Masuo M., Somlyo A. P. G protein-mediated inhibition of myosin light-chain phosphatase in vascular smooth muscle. Proc Natl Acad Sci U S A. 1991 Oct 15;88(20):9307–9310. doi: 10.1073/pnas.88.20.9307. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lydrup M. L., Swärd K., Hellstrand P. Effect of glibenclamide on membrane response to metabolic inhibition in smooth muscle of rat portal vein. J Vasc Res. 1994 Mar-Apr;31(2):82–91. doi: 10.1159/000159034. [DOI] [PubMed] [Google Scholar]
- Molnár M., Hertelendy F. Signal transduction in rat myometrial cells: comparison of the actions of endothelin-1, oxytocin and prostaglandin F2 alpha. Eur J Endocrinol. 1995 Oct;133(4):467–474. doi: 10.1530/eje.0.1330467. [DOI] [PubMed] [Google Scholar]
- Neering I. R., Morgan K. G. Use of aequorin to study excitation--contraction coupling in mammalian smooth muscle. Nature. 1980 Dec 11;288(5791):585–587. doi: 10.1038/288585a0. [DOI] [PubMed] [Google Scholar]
- Okashiro T., Tokuno H., Fukumitsu T., Hayashi H., Tomita T. Effects of intracellular ATP on calcium current in freshly dispersed single cells of guinea-pig portal vein. Exp Physiol. 1992 Sep;77(5):719–731. doi: 10.1113/expphysiol.1992.sp003638. [DOI] [PubMed] [Google Scholar]
- Osterman A., Arner A. Effects of inorganic phosphate on cross-bridge kinetics at different activation levels in skinned guinea-pig smooth muscle. J Physiol. 1995 Apr 15;484(Pt 2):369–383. doi: 10.1113/jphysiol.1995.sp020671. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Paul R. J. Smooth muscle energetics. Annu Rev Physiol. 1989;51:331–349. doi: 10.1146/annurev.ph.51.030189.001555. [DOI] [PubMed] [Google Scholar]
- Rembold C. M., Murphy R. A. Myoplasmic [Ca2+] determines myosin phosphorylation in agonist-stimulated swine arterial smooth muscle. Circ Res. 1988 Sep;63(3):593–603. doi: 10.1161/01.res.63.3.593. [DOI] [PubMed] [Google Scholar]
- Rizzuto R., Brini M., Murgia M., Pozzan T. Microdomains with high Ca2+ close to IP3-sensitive channels that are sensed by neighboring mitochondria. Science. 1993 Oct 29;262(5134):744–747. doi: 10.1126/science.8235595. [DOI] [PubMed] [Google Scholar]
- Taggart M. J., Burdyga T., Heaton R., Wray S. Stimulus-dependent modulation of smooth muscle intracellular calcium and force by altered intracellular pH. Pflugers Arch. 1996 Sep;432(5):803–811. doi: 10.1007/s004240050202. [DOI] [PubMed] [Google Scholar]
- Taggart M. J., Wray S. The effect of metabolic inhibition on rat uterine intracellular pH and its role in contractile failure. Pflugers Arch. 1995 May;430(1):125–131. doi: 10.1007/BF00373847. [DOI] [PubMed] [Google Scholar]
- Tansey M. G., Luby-Phelps K., Kamm K. E., Stull J. T. Ca(2+)-dependent phosphorylation of myosin light chain kinase decreases the Ca2+ sensitivity of light chain phosphorylation within smooth muscle cells. J Biol Chem. 1994 Apr 1;269(13):9912–9920. [PubMed] [Google Scholar]
- Wingard C. J., Paul R. J., Murphy R. A. Dependence of ATP consumption on cross-bridge phosphorylation in swine carotid smooth muscle. J Physiol. 1994 Nov 15;481(Pt 1):111–117. doi: 10.1113/jphysiol.1994.sp020422. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wray S. The effects of metabolic inhibition on uterine metabolism and intracellular pH in the rat. J Physiol. 1990 Apr;423:411–423. doi: 10.1113/jphysiol.1990.sp018030. [DOI] [PMC free article] [PubMed] [Google Scholar]