Effects of exercise on the cardiovascular function of rats in a sulfur dioxide polluted environment

Abstract

The purpose of the study is to further explore the combined effects of exercise and sulfur dioxide (SO₂) exposure on the cardiovascular function as well as the underlying mechanisms. Rats were randomly divided into 4 groups: rest group (RG), exercise group (EG), SO₂ pollution group (SG) and SO₂ pollution + exercise group (SEG). Changes of aortic pressure and left ventricular pressure, Ang II concentration, ACE concentration and ACE activity in rats’ myocardial tissue were observed. Compared with RG, the systolic blood pressure, pulse pressure, LVSP, +dp/dtmax and -dp/dtmax of EG increased significantly, diastolic blood pressure, resting heart rate and ACE activity decreased significantly; For rats of SG, 4 weeks SO₂ exposure increased LVEDP, Ang II concentration, ACE concentration and ACE activity, decreased the +dp/dtmax and -dp/dtmax; For rats of SEG, the systolic blood pressure, pulse pressure, LVSP, +dp/dtmax and -dp/dtmax decreased significantly, HR, LVEDP, Ang II concentration, ACE concentration and ACE activity increased significantly. Results indicate that, the combination of aerobic exercise and SO₂ exposure can aggravate the negative effects of SO₂ inhalation on cardiovascular function. Renin-angiotensin system plays an important role in mediating the negative effect of SO₂ inhalation.

Key words
sulfur dioxide; exercise; haemodynamics; Ang II; ACE