OBJECTIVETo investigate the influence of acupuncture parameters on the acupuncture effect through the cluster analysis in Wistar rat model with middle cerebral artery occlusion (MCAO).

METHODSDuplicated MCAO models by Zea-longa's thread ligation and chose rats with 1-3 scores assessed by Zausinger's six-score method to be grouped. The rats were divided into 6 basic control groups [(including a normal group, a sham group, a model control group, a model group without intervention, a Nimodipine group, a lateral-to-Renzhong (DU6) group] and 6 acupuncture groups [a Neiguan (PC6) group, a Weizhong (BL40) group, a Sanyinjiao (SP6) group, a Chize (LU5) group, a Renzhong (DU6) group and a Feixue (non-acupoint) group]. In the acupuncture groups, for every acupoint or needling site, 9 different parameters [2 factors (frequency and time) and 3 levels (180, 120, and 60 cpm of the frequency and 5, 60, and 180 s of the time)] were set respectively by the orthogonal intersection method, in total 54 groups. The rats were treated by acupuncture with a lifting-thrusting manipulation once every 12 h, in total 6 times. Neurobehavioral scores, cerebral blood flow, infarction rate, microcirculation, light microscopy, etc. were measured. The factor analysis was first applied to get the comprehensive effect scores of the samples in the acupuncture groups and then by which the cluster analysis was made with the statistical software of SPSS17.0.

RESULTSFor the Neiguan (PC6) group, the exceptional results of acupuncture comprehensive effect were parameters 7, 8, 9, 10; the valid results were parameters 2, 3, 4, and the invalid were parameters 5, 6. For the Weizhong (BL40) group, the exceptional results were parameters 2, 4; the valid results were parameters 3, 5, 6, 7, and the invalid were parameters 8, 9, 10. For the Chize (LU5) group, the exceptional results were parameters 7, 8; the valid results were parameters 3, 4, 5, 6, 9, 10; and the invalid was parameter 2. For the Sanyinjiao (SP6) group, the exceptional results were parameters 4, 6; the valid results were parameters 2, 3, 5; and the invalid were parameters 7, 8, 9,10. For the Renzhong (DU6) group, the exceptional results were parameters 3, 4, 6, 7, 9, 10; the valid results were parameters 2, 5; and the invalid was parameter 8. For the Non-acupoint group, the exceptional result was parameter 10; the valid results were parameters 2, 3, 4, 7, 9; and the invalid were parameters 5, 6, 8.

CONCLUSIONSFor each meridian acupoint, different acupuncture parameters could consequently get a different acupuncture effect; each meridian acupoint had the most suitable or optimal acupuncture parameters; acupuncture parameters might be the main factors impacting on acupuncture effect.