Effects of electroacupuncture at meridian point on the mRNA expressions of corticotropin-releasing factor and corticosteroid in the hippocampus after cerebral ischemia reperfusion in rats

Abstract

Objective To investigate the effects of electroacupuncture at meridian point on the mRNA expressions of corticotropin-releasing factor (CRF) and corticosteroid (CORT) in the hippocampus after cerebral ischemia reperfusion in rats. Methods A total of 150 SD rats were randomly divided into 5 groups by random number table method: normal control group, sham operation group, model group, meridian point electroacupuncture group and non-meridian point electroacupuncture group, with 30 rats in each group. A model of focal cerebral ischemic reperfusion was induced using the modified intraluminal thread method. In the meridian point electroacupuncture group, at 6 h after cerebral ischemia reperfusion, acupuncture “LI11” on both sides, bilateral “ST36”, “GV20”, ”GV16” daily for 7 d. The neurological deficits were evaluated 1 d, 3 d, and 7 d after cerebral ischemia reperfusion, and then all rats were sacrificed and the hippocampi were harvested. The mRNA expressions of CRF and CORT in the hippocampus were determined by quantitative real-time PCR. Results The mRNA expressions of CRF (1.122 ± 0.249, 1.190 ± 0.666, 0.454 ± 0.612 in the model group; 0.021 ± 0.049, 0.021 ± 0.027, 0.035 ± 0.005 in the sham operation group) and CORT (0.917 ± 0.113, 1.024 ± 0.290, 0.709 ± 0.055 in the model group; 0.016 ± 0.013, 0.016 ± 0.006, 0.043 ± 0.006 in the sham operation group) in the hippocampus 1 d, 3 d, 7 d after cerebral ischemic reperfusion were significantly increased in the model group compared with the sham operation group (all P<0.01). The mRNA expressions of CRF (0.424 ± 0.104, 0.339 ± 0.476, 0.095 ± 0.021) and CORT (0.377 ± 0.073, 0.138 ± 0.025, 0.158 ± 0.010) in the hippocampus 1 d, 3 d, 7 d after cerebral ischemic reperfusion were significantly decreased in the meridian point electroacupuncture group compared with the mode1 group (all P<0.01). The neurological deficits scale 1 d, 3 d, 7 d after cerebral ischemic reperfusion were significantly decreased in the meridian point electroacupuncture group compared with the mode1 group (1.83 ± 0.75, 1.50 ± 0.55 and 1.17±0.41 in the meridian point electroacupuncture group; 2.50 ± 0.84, 2.33 ± 0.52 and 1.67 ± 0.52 in the model graoup; all P<0.01). Conclusion Electricacupuncture at meridian point can reduce the mRNA expressions of CRF and CORT in the hippocampus, and improve neurological deficits after cerebral ischemia reperfusion in rats. Key words: Brain ischemia; Reperfusion injury; Electroacupuncture; Corticotropin-releasing hormone; Glucocorticoids; Gene expression; Rats