OBJECTIVE  To construct a rat model of Qi deficiency and blood stasis type cerebral ischemia/reperfusion based on the theory of "labor leads to Qi depletion" in traditional Chinese medicine, and analyze its biological characteristics.

METHODS The rats were randomly divided into sham operation group, middle cerebral artery occlusion(MCAO) group, and composite modeling group. The MCAO group was blocked left middle cerebral artery by the wire embolus method for 2 h and reperfused for 48 h. The composite modeling group first underwent continuous exhaustion swimming for 21 d, followed by 2 h of ischemia and 48 h of reperfusion with the MCAO group. The neurological deficits of the model and the evidence of Qi deficiency and blood stasis were assessed by the Longa score and the Qi deficiency and blood stasis scale, and the pathomorphological changes of the brain tissue were observed by 2,3,5-triphenyltetrazolium chloride(TTC) staining, HE staining, and Nissl staining, and the permeability of the blood-brain barrier was detected by immunofluorescent IgG, and the brain tissue was examined for adenosine triphosphate(ATP), Na⁺, K⁺-ATPase, adenosine diphosphate(ADP), malondialdehyde(MDA), total superoxide dismutase(T-SOD) by colorimetric assay, and serum interleukin-1β(IL-1β) and interleukin-6(IL-6) levels were detected by ELISA.

RESULTS Compared with the sham operation group, the Longa score and Qi deficiency and blood stasis syndrome score were significantly increased in the MCAO group(P<0.01), the cerebral infarction rate and cerebral edema rate increased significantly(P<0.01), the pathological damage in the CA1 area of the hippocampus was aggravated(P<0.01), the number of Nissl bodies was significantly reduced(P<0.01), and the average fluorescent intensity of IgG at the blood-brain barrier was significantly increased(P<0.05 or P<0.01 ); the ATP and ADP content of brain tissue, Na⁺, K⁺-ATPase activity were significantly decreased(P<0.05 or P<0.01); serum MDA, IL-1β, and IL-6 were significantly increased(P<0.05 or P<0.01), and T-SOD was significantly decreased(P<0.01). Compared with the MCAO group, the composite modeling group had a significant increase in Longa scores and Qi deficiency and blood stasis symptom scores(P<0.05 or P<0.01), cerebral infarction rate and cerebral edema rate were significantly increased(P<0.01), and the average fluorescence intensity of blood-brain barrier IgG was significantly increased(P<0.01); brain tissue ATP, ADP content, and Na⁺, K⁺-ATPase activity were significantly decreased(P<0.05 or P<0.01); serum MDA, IL-1β, and IL-6 were significantly increased(P<0.05 or P<0.01), and T-SOD was significantly decreased(P<0.01).

CONCLUSION Forceful swimming combined with MCAO method can construct a rat model of cerebral ischemia/reperfusion injury of Qi deficiency and blood stasis types, which is simple and easy to implement, with both cerebral ischemia and Qi deficiency and blood stasis phenotypes, and has heavier neurological deficits, Qi deficiency and blood stasis phenotypes, tissue injuries, impaired energy metabolism of brain tissues, and oxidative stress and inflammatory response of organisms, as compared with MCAO alone.