Comparison of Beneficial Effects of Acupuncture at PC6, LU7 & Non-acupuncture Points on Cardiac Cell Function in Myocardial Ischemia (MI) Rats by Testing Protein Expression of L-type Calcium Channel Protein and its Related Protein

Abstract

The mechanism of why electro-acupuncture (EA) at PC6 improves the heart function was investigated by studying how the L-type cardiac voltage-dependent calcium channel in myocardial ischemia (MI) is regulated. Cavaα1c, Cavβ and Cavaα2-δ1 are main component proteins of L-type calcium channel; CaM and Calmodulin kinase II (CaMKII) are Ca2+ channel associated proteins. In this experiment, MI was induced by injection of isoproterenol (ISO) in rats and electrocardiograms (ECGs) were recorded before and after every injection, and protein expressions of Cavaα1c, Cavβ, Cavaα2-δ1, CaM and CaMKII were higher [The protein expression increased 43.39%, 54.85%, 47.08%, 48.29% and 50.36% respectively] than the control rats significantly (p<0.05). After MI induction, the MI rats were divided into three groups, including PC6 (Neiguan-point), LU7 (Lieque-point) and Non-acupuncture-point group, which were acupunctured once a day for 7 days respectively. After EA at PC6, the protein expressions showed obvious decrease [EA at PC6: the protein expressions of Cavaα1c, Cavβ, Cavaα2-δ1, CaM and CaMKII decreased 26.36%, 27.58%, 25.21%, 27.21% and 26.61% respectively.] and they are all lower than MI rats significantly (p<0.05). After EA at LU7 and Non-acupuncture-point, the protein expressions showed no significant changes. The effect of EA at PC6 was significantly better than LU7 and Non-acupuncture-point (p<0.05). PC6 is an acupoint of the pericardium meridian, and the pericardium meridian, which corresponds to opioid system according to Li P's research, can affect the cardio-vascular function directly. LU7 is located on the lung meridian; it cannot affect the heart function directly although the lung is related to the heart in blood circulation function so PC6 showed the target treating effect of meridian specificity on regulating the L-type calcium channel in MI.