Document Type : Research Paper
Authors
Abstract
Endothelin-1 is a strong vasoconstrictor that is secreted by endothelial cells and is identified as the strongest vascular constrictor. The aim of the present study was to investigate the role of resistance exercises on plasma endothelin-1 concentration and its relationship with the blood pressure of older women. For this reason, 20 postmenopausal women (mean age: 67.37±6.02 years, height: 153.02±8.12 cm, weight: 65.78±12.03 kg, BMI of 26.78±4.16 kg/m2) were selected and randomly assigned into two groups (n=10). The experimental group performed eight weeks of resistance training, three sessions per week with the intensity of 40 to 65% of one maximum repetition. Before and after eight weeks of exercise, the resting level of endothelin-1 concentration, the systolic and diastolic blood pressure was measured. Within group and between group changes were assessed by paired sample t-test and independent t-test respectively. Pearson correlation coefficient was used for investigating the relationship between endothelin-1 and blood pressure The results showed that resistance exercise has a significant effect on endothelin_1 plasma decrease of old women (p=0.007). Also, one period of resistance exercise has a significant effect on decreasing systolic (p=0.004) and diastolic (p=0.001) blood pressure of old women. There is a direct correlation between endothelin_1 and systolic blood pressure (p=0.542). However, there was no correlation between endothelin_1 and diastolic blood pressure (r=378).Overally, with respect to decrease in plasma endothelin_1 concentration and systolic and diastolic blood pressure after resistance exercise and the relationship of endothelin_1 with systolic blood pressure, it appears that resistance exercise training with this intensity and volume can have effect on decreasing the systolic and diastolic blood pressure and also decreasing endothelin_1 concentration of plasma as a cardiovascular risk factor for hypertension of older women.
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