Journal of Applied Physiology, Vol 78, Issue 3 1079-1087, Copyright © 1995 by American Physiological Society

ARTICLES

Exercise training alters the Ca2+ and contractile responses of coronary arteries to endothelin

D. K. Bowles, M. H. Laughlin and M. Sturek
Dalton Cardiovascular Research Center, Department of Physiology, University of Missouri, Columbia 65211, USA.

We tested the hypothesis that alterations in myoplasmic free Ca2+ (Ca(m)) regulation in coronary smooth muscle after exercise training (Ex) underlie changes in vasomotor function. Yucatan miniature pigs were endurance trained by treadmill running for 16-20 wk. Simultaneous determination of Ca(m) (fura-2 microfluorometry) and contraction during endothelin exposure in coronary arteries were then performed. Endothelin (10(-9) to 10(-7) M) was administered either cumulatively or as a single concentration. Ex significantly attenuated the Ca(m) response to 10(-9) and 10(-8) M endothelin. Developed tension was significantly diminished at 10(-8) M endothelin in Ex pigs, producing a rightward shift in the concentration-developed tension response. Attenuated Ca(m) and contractile response to 10(-8) M endothelin were present after Ex whether endothelin was applied cumulatively or as a single concentration. The developed tension-Ca(m) relationship showed an increased Ca(m) sensitivity of contraction with Ex. Endothelin (10(-8) M)-induced Ca2+ influx, estimated by Ba2+ influx in low-Na+ solution, was increased threefold in coronary arteries from Ex pigs. The decreased Ca(m) in the presence of increased divalent cation (i.e., Ca2+) influx during 10(-8) M endothelin suggests a greatly enhanced sarcolemmal Ca2+ cycling in coronary arteries from Ex pigs.

This article has been cited by other articles:

				Y. Yang, A. W. Jones, T. R. Thomas, and L. J. Rubin Influence of sex, high-fat diet, and exercise training on potassium currents of swine coronary smooth muscle Am J Physiol Heart Circ Physiol, September 1, 2007; 293(3): H1553 - H1563. [Abstract] [Full Text] [PDF]

				C. A. Witczak, B. R. Wamhoff, and M. Sturek Exercise training prevents Ca2+ dysregulation in coronary smooth muscle from diabetic dyslipidemic yucatan swine J Appl Physiol, September 1, 2006; 101(3): 752 - 762. [Abstract] [Full Text] [PDF]

				E. A. Mokelke, N. J. Dietz, D. M. Eckman, M. T. Nelson, and M. Sturek Diabetic dyslipidemia and exercise affect coronary tone and differential regulation of conduit and microvessel K+ current Am J Physiol Heart Circ Physiol, March 1, 2005; 288(3): H1233 - H1241. [Abstract] [Full Text] [PDF]

				B. R. Wamhoff, D. K. Bowles, N. J. Dietz, Q. Hu, and M. Sturek Exercise training attenuates coronary smooth muscle phenotypic modulation and nuclear Ca2+ signaling Am J Physiol Heart Circ Physiol, December 1, 2002; 283(6): H2397 - H2410. [Abstract] [Full Text] [PDF]

				J. J Jones, N. J Dietz, C. L Heaps, J. L Parker, and M. Sturek Calcium buffering in coronary smooth muscle after chronic occlusion and exercise training Cardiovasc Res, August 1, 2001; 51(2): 359 - 367. [Abstract] [Full Text] [PDF]

				B. J. F. Hill, L. C. Katwa, B. R. Wamhoff, and M. Sturek Enhanced EndothelinA Receptor-Mediated Calcium Mobilization and Contraction in Organ Cultured Porcine Coronary Arteries J. Pharmacol. Exp. Ther., November 1, 2000; 295(2): 484 - 491. [Abstract] [Full Text]

				J. D. Symons, S. V. Rendig, C. L. Stebbins, and J. C. Longhurst Microvascular and myocardial contractile responses to ischemia: influence of exercise training J Appl Physiol, February 1, 2000; 88(2): 433 - 442. [Abstract] [Full Text] [PDF]

				J. L. Dixon, J. D. Stoops, J. L. Parker, M. H. Laughlin, G. A. Weisman, and M. Sturek Dyslipidemia and Vascular Dysfunction in Diabetic Pigs Fed an Atherogenic Diet Arterioscler. Thromb. Vasc. Biol., December 1, 1999; 19(12): 2981 - 2992. [Abstract] [Full Text] [PDF]

				D. K. Bowles, Q. Hu, M. H. Laughlin, and M. Sturek Exercise training increases L-type calcium current density in coronary smooth muscle Am J Physiol Heart Circ Physiol, December 1, 1998; 275(6): H2159 - H2169. [Abstract] [Full Text] [PDF]

				D. K. Bowles, M. H. Laughlin, and M. Sturek Exercise training increases K+-channel contribution to regulation of coronary arterial tone J Appl Physiol, April 1, 1998; 84(4): 1225 - 1233. [Abstract] [Full Text] [PDF]

				J. A. Rapps, M. Sturek, A. W. Jones, and J. L. Parker Altered reactivity of coronary arteries located distal to a chronic coronary occlusion Am J Physiol Heart Circ Physiol, October 1, 1997; 273(4): H1879 - H1887. [Abstract] [Full Text] [PDF]

				J. A. Rapps, A. W. Jones, M. Sturek, L. Magliola, and J. L. Parker Mechanisms of Altered Contractile Responses to Vasopressin and Endothelin in Canine Coronary Collateral Arteries Circulation, January 7, 1997; 95(1): 231 - 239. [Abstract] [Full Text]

				E. O. Ojuka, T. E. Jones, L. A. Nolte, M. Chen, B. R. Wamhoff, M. Sturek, and J. O. Holloszy Regulation of GLUT4 biogenesis in muscle: evidence for involvement of AMPK and Ca2+ Am J Physiol Endocrinol Metab, May 1, 2002; 282(5): E1008 - E1013. [Abstract] [Full Text] [PDF]