Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

  • Heart, Circulation, Respiration and Blood; Environmental and Exercise Physiology
  • Published:

Relaxation of tetanized canine tracheal smooth muscle

  • 14 Accesses

  • 5 Citations


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.

This is a preview of subscription content, log in to check access.


  1. 1.

    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

  2. 2.

    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

  3. 3.

    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

  4. 4.

    Brutsaert DL, Claes VA (1974) Onset of mechanical activation of mammalian heart muscle in calcium- and strontium-containing solutions. Circ Res 35:345–357

  5. 5.

    Brutsaert DL, De Clerck NM, Goethals MA, Housmans PR (1978) Relaxation of ventricular cardiac muscle. J Physiol 283:469–480

  6. 6.

    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

  7. 7.

    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

  8. 8.

    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

  9. 9.

    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

  10. 10.

    Conti MA, Adelstein RS (1980) Phosphorylation by c-AMP dependent protein kinase regulates myosin light chain kinase. Fed Proc 39:355–368

  11. 11.

    Ebashi S (1980) The Croonian Lecture 1979. Regulation of muscle contraction. Proc Roy Soc Lond B 207:259–286

  12. 12.

    Fabiato A, Fabiato F (1977) Calcium release from the sacroplasmic reticulum. Circ Res 40:119–129

  13. 13.

    Johansson B, Hellstrand P (1975) Isometric and isotonic relaxation in venous smooth muscle. Acta Physiol Scand 93:167–174

  14. 14.

    Klee CB, Crouch TH, Richman PG (1980) Calmodulin. In: Ann Rev Biochem 49:489–515

  15. 15.

    Marston SB, Trevett RM, Walters M (1980) Calcium ion-regulated filaments from vascular smooth muscle. Biochem J 185:355–368

  16. 16.

    Murphy RA (1977) Control of the actin-myosin interaction in vascular smooth muscle. Blood Vessels 14:241–242

  17. 17.

    Niedegerke R (1963) Movements in calcium in beating ventricles of the frog heart. J Physiol 167:551–580

  18. 18.

    Parmley WW, Sonnenblick EH (1969) Relation between mechanics of contraction, and relaxation in mammalian cardiac muscle. Am J Physiol 216:1084–1091

  19. 19.

    Shibata S, Cheng JB (1977) Relaxation of vascular smooth muscles in spontaneously hypertensive rats. Blood Vessels 14:247–248

  20. 20.

    Soulsrada JF, Kaut G, Loader J (1977) Physiological and biochemical characteristics of asthmatic airway smooth muscle. Fed Proc Abs 90

  21. 21.

    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

  22. 22.

    Vassort G (1973) Influence of sodium ions on the regulation of frog myocardial contractility. Pflügers Arch 339:225–240

  23. 23.

    Winegrad, S (1973) Intracellular calcium bindings and release in frog heart. J Gen Physiol 62:693–706

Download references

Author information

Correspondence to Dirk L. Brutsaert.

Rights and permissions

Reprints 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

Download citation

Key words

  • Smooth muscle relaxation
  • Airway smooth muscle
  • Inactivation dependent relaxation
  • Tracheal smooth muscle
  • Load-insensitive relaxation