Objective: To observe the effect of acupuncture (Acupunct) on cerebral infarction volume and expression of poly ADP ribose polymerase 1 (PARP1), apoptosis-inducing factor (AIF) and endonuclease G (Endo-G) in the cerebral cortex tissue at different time-points after cerebral ischemia (CI) in acute cerebral infarction rats, so as to explore its underlying mechanisms in prolonging time window of thrombolysis.
Methods: Forty-eight SD rats were randomly divided into sham operation, model, intravenous thrombolysis (IVT)-4.5 h, IVT-6 h, IVT-9 h, Acupunct＋IVT-4.5 h, Acupunct ＋IVT-6 h, Acupunct＋IVT-9 h groups (n＝6 in each group). The CI model was established by using modified autologous thromboembolism via the right common carotid artery. Two hours after modeling, rats of the Acupunct groups received Acupunct stimulation of "Shuigou" (GV26) and bilateral "Neiguan" (PC6) for 30 min. Thrombolysis was conducted by injection of recombinant human tissue-type plasminogen activator (rt-PA, 10 mg/kg) via caudal vein. The neurological deficit was assessed with reference to Bederson's methods. 2，3，5-triphenyltetrazolium chloride (TTC) staining was used to assess the cerebral infarction volume, and the expression of cerebral PARP1, AIF and Endo-G proteins detected by Western blot.
Results: Compared with the sham operation group, the neurological score and percentage of cerebral infarction volume, expression levels of PARP1, AIF and Endo-G proteins were significantly increased in the model group (P<0.01，P<0.05). After the intervention, modeling-induced increase of the aforementioned indexes was reversed in the IVT-4.5 h, Acupunct＋IVT-4.5 h and Acupunct＋IVT-6 h groups (P<0.05), except PARP1 expression of the Acupunct＋IVT 6 h group (P>0.05). The levels of neurological score, percentage of cerebral infarction volume, and AIF expression were significantly lower in both the Acupunct＋IVT 4.5 h and Acupunct＋IVT-6 h groups than in the simple IVT-4.5 h and simple IVT-6 h groups, respectively (P<0.05), and the expression levels of PARP1 and Endo-G proteins were obviously lower in the Acupunct＋IVT-4.5 h group than in the IVT-4.5 h group (P<0.05). Endo-G proteins were obviously lower in the Acupunct＋IVT-9 h group than in the IVT-9 h group (P<0.05).
Conclusion: Acupuncture may improve neurological function, reduce cerebral infarction volume and prolong the time window of thrombolysis in CI rats, which may be associated with its effect in suppressing AIF/PARP1/ Endo-G signaling.
Keywords: Acupuncture; Apoptosisinducing factor; Cerebral infarction; Endonuclease Ga; Poly ADP ribose polymerase 1; Thrombolysis time window.