Protective effects of hyperbaric oxygen and acupuncture preconditioning on the injury induced by acute myocardial ischemia reperfusion in rats

Abstract

Objective To investigate the protective effects of hyperbaric oxygen(HBO)and acupuncture preconditioning on the injury induced by acute myocardial ischemia reperfusion in rat model. Methods Thirty-six SD rats were randomly divided into 3 groups: the sham surgery group (or the sham group), the model group and the HBO and acupuncture group (or the combined group), each consisting of 12 animals. The combined group received acupuncture treatment at Neikuan acupoint bilaterally with the needles remaining, then was placed into the animal chamber and exposed to HBO at a pressure of 0.2 MPa for 1 hour a session, 2 sessions a day, and for a succession of 5 days. Then, the myocardial ischemia reperfusion injury model was established. For the model and the combined groups, the myocardial ischemia reperfusion injury model was established by ligation of the left anterior descending branch of the coronary artery for 40 minutes and then reperfusion was performed for 2 hours. The sham group only received open chest surgery without the development of the model. Cardiac functions, such as left ventricular systolic pressure (LVSP), left ventricular diastolic pressure (LVDP), maximal increasing and decreasing rates of left intraventricular pressure [±(dP/dt)max] were monitored in the rats of the 3 groups after reperfusion. Morphological injury was measured with Hematoxylin and Eosin (HE) staining, and apoptosis of cardiac cells in the affected area was detected with TUNEL. Results LVSP of the model group is (112.64±8.49) mmHg, LVDP is (6.75±1.34) mmHg, + (dP/dt)max is (2 970.15±137.91) mmHg/s, -(dp/dt)max is (2 936.86±179.50) mmHg/s; LVSP of the combined group is (123.33±7.86) mmHg, LVDP is (6.13±1.56) mmHg, + (dp/dt) max is (3 046.56±137.91) mmHg/s, -(dp/dt) max is (3 022.30+ 283.73) mmHg/s. The apoptosis rate of the model group is (94.58±34.01)%, and the apoptosis rate of the combined group is (42.17±27.61)%. As compared with that of the model group, reperfusion injury was significantly less severer for the combined group, and morphological lesion in the affected area was alleviated, cardiac function improved and apoptosis of cardiac cells was also alleviated considerably. Conclusions HBO combined with acupuncture at Neikuan acupoint could produce good protective effect on the rat with myocardial ischemia reperfusion injury. Key words: Myocardial ischemia reperfusion injury; Hyperbaric oxygen; Acupuncture; Rats