Objective: To observe the effect of different emulated acupuncture-needle manipulations on blood pressure and myocardial angiotensin (Ang) II content in spontaneously hypertensive rats (SHR), so as to seek a better acupuncture parameter for clinical treatment of hypertension.
Methods: Thirty-three SHR were randomly divided into mild-stimulation group (n=8), moderate-stimulation group (n=8), heavy-stimulation group (n=8) and model group (n=9). Additionally, other 8 normal rats were made up of control group. Blood pressure (BP) was determined by using a non-invasive BP detection system. Myocardial Ang II content was assayed by radioimmunoassay. The emulated acupuncture-needle twirling angles and frequencies of 144 degrees, 75 r/min; 255 degrees, 111 r/min; and 360 degrees, 140 r/min in mild, moderate and heavy manipulations were applied to bilateral "Zusanli" (ST 36) and "Taichong" (LR 3) for 3 min, once daily for 3 weeks, with an interval of 2 days between every two weeks.
Results: Compared with pre-therapy, BP values of both heavy-stimulation and model groups increased significantly (P<0.01); and compared with model group, BP values of mild-stimulation and moderate-stimulation groups decreased significantly after the therapy (P<0.05), but were still higher than that of control group (P<0.05). In addition, myocardial Ang II contents of mild-stimulation, moderate-stimulation, heavy-stimulation and model groups were significantly higher than that of control group (P<0.05). No significant differences were found between mild-stimulation and moderate-stimulation groups, and between heavy-stimulation and model groups after therapy in BP, and among mild-stimulation, moderate-stimulation, heavy-stimulation and model groups in myocardial Ang II contents (P>0.05).
Conclusion: Mild and moderate manipulations of ST36 and LR3 have apparent influence on BP, but no apparent influence on myocardial Ang II content.