[Effect of Electroacupuncture on Expression of Scavenger Receptor A I in Peritoneal Macrophages of Atherosclerotic Rabbits].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on the expression of scavenger receptor A I (SR-A I) protein and mRNA in peritoneal macrophages of atherosclerosis (AS) rabbits.

METHODS: A total of 26 New Zealand rabbits were used in the present study, among them, 7 were randomly selected to constitute a blank control group, and the rest 19 rabbits were fed with high-fat diet combined with carotid artery balloon injury for establishing AS model. Eight weeks after high-fat forage feeding, one high-fat fed rabbit and one normal rabbit were randomly selected for verifying the success of modeling. HE staining was employed to examine pathological changes of the common carotid artery after paraffin section. Then the rest 18 rabbits were randomly divided into model, EA and medication groups ( n =6 rabbits in each). EA (2 Hz, 1 mA) was applied at "Guanyuan"(ST 25)and bilateral "Zusanli"(ST 36) and "Neiguan" (PC 6) for 20 min. The rabbits of the medication group were treated by gavage of Atorvastatin Calcium (1 mg•kg-1 • d-1 ), and those of the model group treated by gavage of distilled water (2 mL•kg-1 •d-1 ). The treatment was given once daily for 4 weeks, with one day's interval between every two weeks. Three days before termination of the experiments, sterile starch solution (3-4 mL/animal) was injected into the peritoneal cavity, and at the end of the experiment, the peritoneal fluid was collected and centrifugated to be cultivated in Dulbecco's Modified Eagle Medium (DMEM) for collecting the macrophages. The expression of SR-A I protein and mRNA in macrophages was assayed by Western blot and PCR, respectively.

RESULTS: HE staining displayed an injury of the inner membrane of the carotid artery marked by observable atherosclerotic plaques, interruption, thickening and uplift, inflammatory cell infiltration, etc. in the AS model rabbits which were relatively milder in both EA and medication groups. The expression levels of SR-A I protein and mRNA were significantly up-regulated in the model group relevant to the blank control group ( P <0.01), and considerably down-regulated in both EA and medication groups compared with the model group ( P <0.01). There were no statistical differences between the EA and medication groups in the decreased levels of expression of SR-A I protein and mRNA ( P >0.05).

CONCLUSION: EA intervention may improve the severity of atherosclerosis to a certain degree in AS rabbits, which is possibly associated with its effect in inhibiting the expression of SR-A I protein and mRNA in the peritoneal macrophages.