Abstract
As is the case for striated muscle, relaxation in smooth muscle has been little studied and is less understood. We report studies of load bearing capacity during relaxation of airway smooth muscle. The model employed was the canine tracheal smooth muscle (TSM). The effect of load on the time course of relaxation was analyzed either by comparing afterloaded contractions against various loads or by imposing abrupt alterations in load (load clamps). Unlike mammalian cardiac muscle in which relaxation was reported sensitive to loading conditions, relaxation in TSM was largely independent of loading conditions. In this it resembled frog heart muscle and mammalian cardiac muscle cells without functioning calcium sequestering systems. This type of relaxation which is not influenced by manipulation of loading conditions, has been termed ‘inactivation-dependent’ relaxation. It appears to operate in muscle tissue in which the calcium sequestering apparatus is poorly developed and the dissipation of activation (removal of activating calcium, detachment of force generating sites, etc.) appears to be the rate limiting step during relaxation.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Aksoy MO, William D, Sharkey EM, Hartshorne DJ (1976) A relationship between Ca2+ sensitivity and phosphorylation of gizzard actomyosin. Biochem Biophys Res Commun 69:35–44
Barron JT, Barany M, Barany K, Storti RV (1980) Reversible phosphorylation and dephosphorylation of the 20,000 dalton light chain of myosin during the contraction-relaxation-contraction of arterial smooth muscle. J Biol Chem 255:6238–6244
Brutsaert DL (1974) Force-velocity-length-time interrelationship of cardiac muscle. In: Physiological basis of Starling's Law of the Heart, Ciba Foundation Symposium 24 (new series). ASP Elsevier, Excerpta Medica, North Holland, Amsterdam, pp 155–175
Brutsaert DL, Claes VA (1974) Onset of mechanical activation of mammalian heart muscle in calcium- and strontium-containing solutions. Circ Res 35:345–357
Brutsaert DL, De Clerck NM, Goethals MA, Housmans PR (1978) Relaxation of ventricular cardiac muscle. J Physiol 283:469–480
Brutsaert DL, Claes VA, De Clerck NM (1978) Relaxation of mammalian single cardiac cells after pre-treatment with the detergent. Brij-58. J Physiol 283:481–491
Brutsaert DL, Housmans PR, Goethals MA (1980) Dual control of relaxation: its role in the ventricular function in the mammalian heart. Circ Res 47:637–652
Chapman RA (1973) The ionic dependence of the strength and spontaneous relaxation of the potassium contracture induced in the heart of the frog,Rana pipiens. J Physiol 231:209–232
Claes VA, Brutsaert DL (1971) Infra-red-emitting diode and optic fibres for underwater force measurement in heart muscle. J Appl Physiol 31:497–498
Conti MA, Adelstein RS (1980) Phosphorylation by c-AMP dependent protein kinase regulates myosin light chain kinase. Fed Proc 39:355–368
Ebashi S (1980) The Croonian Lecture 1979. Regulation of muscle contraction. Proc Roy Soc Lond B 207:259–286
Fabiato A, Fabiato F (1977) Calcium release from the sacroplasmic reticulum. Circ Res 40:119–129
Johansson B, Hellstrand P (1975) Isometric and isotonic relaxation in venous smooth muscle. Acta Physiol Scand 93:167–174
Klee CB, Crouch TH, Richman PG (1980) Calmodulin. In: Ann Rev Biochem 49:489–515
Marston SB, Trevett RM, Walters M (1980) Calcium ion-regulated filaments from vascular smooth muscle. Biochem J 185:355–368
Murphy RA (1977) Control of the actin-myosin interaction in vascular smooth muscle. Blood Vessels 14:241–242
Niedegerke R (1963) Movements in calcium in beating ventricles of the frog heart. J Physiol 167:551–580
Parmley WW, Sonnenblick EH (1969) Relation between mechanics of contraction, and relaxation in mammalian cardiac muscle. Am J Physiol 216:1084–1091
Shibata S, Cheng JB (1977) Relaxation of vascular smooth muscles in spontaneously hypertensive rats. Blood Vessels 14:247–248
Soulsrada JF, Kaut G, Loader J (1977) Physiological and biochemical characteristics of asthmatic airway smooth muscle. Fed Proc Abs 90
Stephens NL (1975) Physical properties of contractile systems. In: Daniel EE, Paton DM (eds) Methods in pharmacology. Vol 3. Plenum, New York, pp 555–591
Vassort G (1973) Influence of sodium ions on the regulation of frog myocardial contractility. Pflügers Arch 339:225–240
Winegrad, S (1973) Intracellular calcium bindings and release in frog heart. J Gen Physiol 62:693–706
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Stephens, N.L., Claes, V.A. & Brutsaert, D.L. Relaxation of tetanized canine tracheal smooth muscle. Pflugers Arch. 390, 175–178 (1981). https://doi.org/10.1007/BF00590203
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00590203