Original Article | Published:

Low-Intensity Voluntary Running Lowers Blood Pressure with Simultaneous Improvement in Endothelium-Dependent Vasodilatation and Insulin Sensitivity in Aged Spontaneously Hypertensive Rats

Hypertension Research volume 31, pages 543552 (2008) | Download Citation

Abstract

Our objective is to examine the effects of voluntary running at different intensity levels on blood pressure, endothelium-dependent vessel dysfunction and insulin resistance in aged spontaneously hypertensive rats (SHR) with severe hypertension. Ten-month-old male and female SHR with severe hypertension were assigned to voluntary running at either low intensity (30% of maximal aerobic velocity) or moderate intensity (60% of maximal aerobic velocity) on a motor-driven treadmill for 6 weeks, 20 min per day and 7 days per week. Age-matched Wistar-Kyoto rats and SHR were kept under sedentary conditions as controls. Blood pressure and heart rate were measured by the tail-cuff method. At the end of the exercise training, blood samples were collected for glucose, insulin and lipids assay, and aortae were isolated to examine their function in vitro. Low-intensity but not moderate-intensity running significantly lowered blood pressure in both male and female SHR (p<0.01). There was significant impairment in acetylcholine-induced vasorelaxation in SHR (p<0.01), which was improved by low-intensity training (p<0.05). Nitric oxide synthase blockade abrogated the improvement in endothelium-dependent relaxation. Hypertensive rats had elevated blood glucose and insulin levels with lowered insulin sensitivity that was ameliorated by low-intensity running. A significant increase in blood high-density lipoprotein (HDL)-cholesterol and a significant decrease in triglycerides were found in exercised SHR. In conclusion, low-intensity voluntary exercise lowers hypertension in aged SHR with severe hypertension. Exercise-induced simultaneous improvement in endothelium-dependent vessel relaxation and insulin sensitivity may act concomitantly in attenuating cardiovascular risk factors in aged hypertensive rats with significantly high blood pressure.

References

  1. 1.

    , , , et al: Reversal of endothelial nitric oxide synthase uncoupling and up-regulation of endothelial nitric oxide synthase expression lowers blood pressure in hypertensive rats. J Am Coll Cardiol 2006; 47: 2536–2544.

  2. 2.

    , , , : Role of endothelium-derived nitric oxide in the abnormal endothelium-dependent vascular relaxation of patients with essential hypertension. Circulation 1993; 87: 1468–1474.

  3. 3.

    , , , et al: Simvastatin improves endothelial function in spontaneously hypertensive rats through a superoxide dismutase mediated antioxidant effect. J Hypertens 2002; 20: 429–438.

  4. 4.

    , , , , , : Vasodilator dysfunction in aged spontaneously hypertensive rats: changes in NO synthase III and soluble guanylyl cyclase expression, and in superoxide anion production. Cardiovasc Res 1998; 37: 772–779.

  5. 5.

    , , , : NCEP-defined metabolic syndrome, diabetes, and prevalence of coronary heart disease among NHANES III participants age 50 years and older. Diabetes 2003; 52: 1210–1214.

  6. 6.

    , , , , : Treatment of spontaneously hypertensive rats with rosiglitazone and/or enalapril restores balance between vasodilator and vasoconstrictor actions of insulin with simultaneous improvement in hypertension and insulin resistance. Diabetes 2006; 55: 3594–3603.

  7. 7.

    , , , et al: Abnormal biopterin metabolism is a major cause of impaired endothelium-dependent relaxation through nitric oxide/O2 imbalance in insulin-resistant rat aorta. Diabetes 1999; 48: 2437–2445.

  8. 8.

    , , , : Skeletal muscle blood flow: a possible line between insulin resistance and blood pressure. Hypertension 1993; 21: 129–135.

  9. 9.

    , , , : Exercise and the nitric oxide vasodilator system. Sports Med 2003; 33: 1013–1035.

  10. 10.

    , , , et al: Gender, exercise training, and eNOS express in porcine skeletal muscle arteries. J Appl Physiol 2003; 95: 250–264.

  11. 11.

    , : Time cause of enhanced endothelium-mediated dilatation in aorta of trained rats. Med Sci Sports Exerc 1997; 29: 1454–1461.

  12. 12.

    , , : Effect of exercise training in 60- to 69-year-old persons with essential hypertension. Am J Cardiol 1989; 64: 348–353.

  13. 13.

    , , , , , : Low-intensity exercise training decreases cardiac output and hypertension in spontaneously hypertensive rats. Am J Physiol 1997; 273: H2627–H2631.

  14. 14.

    , , , , : Chronic exercise and its hemodynamic influences on resting blood pressure of hypertensive rats. J Appl Physiol 1991; 71: 2206–2210.

  15. 15.

    , : Exercise training improves aortic endothelium-dependent vasorelaxation and determinants of nitric oxide bioavailability in spontaneously hypertensive rats. J Appl Physiol 2004; 96: 2088–2096.

  16. 16.

    , , , et al: Enhanced acidotic myocardial Ca2+ responsiveness with training in hypertension. Med Sci Sports Exerc 2006; 38: 847–855.

  17. 17.

    , , , : Effect of spontaneous running on blood pressure, heart rate and cardiac dimensions in developing and established spontaneously hypertension in rats. Acta Physiol Scand 1987; 129: 535–542.

  18. 18.

    , : Heart rate variability and autonomic activity at rest and during exercise in various physiological conditions. Eur J Appl Physiol 2003; 90: 317–325.

  19. 19.

    , , , , : Chronic hypoxia exposure depresses aortic endothelium-dependent vasorelaxation in sedentary and trained rats: involvement of L-arginine. J Appl Physiol 2005; 99: 1029–1035.

  20. 20.

    , , , et al: Astragaloside IV dilates aortic vessels from normal and spontaneously hypertensive rats through endothelium-dependent and endothelium-independent ways. Planta Med 2006; 72: 621–626.

  21. 21.

    : Exercise is good for your blood pressure: effects of endurance training and resistance. Clin Exp Pharmacol Physiol 2006; 33: 853–856.

  22. 22.

    , , , et al: The effects of changes in physical activity on major cardiovascular risk factors, hemodynamics, sympathetic function, and glucose utilization in man: a controlled study of four levels of activity. Circulation 1986; 73: 30–40.

  23. 23.

    : Antihypertensive mechanisms of exercise. J Hypertens 1993; 11: 223–229.

  24. 24.

    , , , et al: Antihypertensive and volume-depleting effects of mild exercise on essential hypertension. Hypertension 1987; 9: 245–252.

  25. 25.

    , , , , , : Effects of ageing and exercise training on endothelium-dependent vasodilatation and structure of rat skeletal muscle arterioles. J Physiol 2004; 556: 947–958.

  26. 26.

    , , , , : Influences of exercise intensity, age, and medication on resting systolic blood pressure of SHR populations. J Appl Physiol 1983; 55: 1305–1310.

  27. 27.

    , , , : Low-intensity exercise training attenuates cardiac β-adrenergic tone during exercise in spontaneously hypertensive rats. Hypertension 1995; 26; 1129–1133.

  28. 28.

    , , , , , : Effect of exercise training on RSNA, baroreflex control, and blood pressure responsiveness. Am J Physiol 1993; 265: R365–R370.

  29. 29.

    , , : Influence of exercise training on neurogenic control of blood pressure in spontaneously hypertensive rats. Hypertension 1999; 34: 720–723.

  30. 30.

    Japanese Society of Hypertension : Japanese Society of Hypertension Guidelines for the Management of Hypertension (JSH 2004). Hypertens Res 2006; 29 ( Suppl): S1–S105.

  31. 31.

    , , : How much exercise is required to reduce blood pressure in essential hypertensioves: a dose-response study. Am J Hypertens 2003; 16: 629–633.

  32. 32.

    , , , : Voluntary running improves glucose tolerance and insulin resistance in female spontaneously hypertensive rats. Am J Hypertens 2001; 14: 708–715.

  33. 33.

    , , , et al: Regular exercise lowers renal but not cardiac sympathetic activity in man. Hypertension 1991; 18: 575–582.

  34. 34.

    , , , , , : Sympathetic nervous system and insulin resistance: from obesity to diabetes. Am J Hypertens 2001; 14: 304S–309S.

  35. 35.

    , , , , , : Effects of exercise training on glomerular structure in fructose-fed spontaneously hypertensive rats. Hypertens Res 2003; 26: 907–914.

  36. 36.

    , , , , : Training in swimming reduces blood pressure and increases muscle glucose transport activity as well as GLUT4 contents in stroke-prone spontaneously hypertensive rats. Appl Human Sci 1998; 17: 275–280.

  37. 37.

    , , , , , : Exogenous hyperinsulinemia causes insulin resistance, hyperendothelinemia, and subsequent hypertension in rats. Metabolism 1999; 48: 465–471.

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Affiliations

  1. Shanghai Research Institute of Sports Science, Shanghai, P.R. China

    • Meng-Wei Sun
    •  & Feng-Lei Qian
  2. College of Exercise and Sport Science, Shanghai University of Sport, Shanghai, P.R. China

    • Meng-Wei Sun
    •  & Ai-Yun Lu
  3. Department of Pharmacology, Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China

    • Jian Wang
    • , Tao Tao
    •  & Hong Chen
  4. Department of General Surgery, Fuzhou General Hospital, Fuzhou, P.R. China

    • Jing Guo
    •  & Lie Wang

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Correspondence to Ai-Yun Lu or Hong Chen.

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DOI

https://doi.org/10.1291/hypres.31.543

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