Effects of propofol anesthesia on noradrenaline release in rat hippocampus

    HE Saiª²Lin, ZHANG Yingª²Min, YUE Yun, CHEN Xiaoª²Guang, GUO Hui, LIU Su

    1Department of Anesthesiology, 304th Hospital of Chinese PLA, Beijing 100037, China, 2Department of Anesthesiology, Chaoyang Hospital, Capital Medical Science University, Beijing 100021, China

    ¡¾Abstract¡¿ AIM: To observe the influences of propofol anesthesia on the release of noradrenaline (NA)and ¦Á2ª²NA receptor inhibitor yohimbine in rat hippocampus so as to identify the mechanisms of central noradrenaline in propofol anesthesia. METHODS: Twenty adult male SD rats were divided randomly into 2 groups. In group A, the rats were infused intravenously (IV) with propofol at a rate of 10 mg/(kg¡¤h) for 45 min and 60 mg/(kg¡¤h) for 45 min and in group B, the rats were given yohimbine 0.5 mg/kg intraperitoneally and were infused IV with propofol as did group A. The release of NA in the extraª²cellular liquid of hippocampus was quantified before propofol anesthesia, in propofol administration and after propofol administration by in vivo microdialysis technique. RESULTS: Compared with those of the group A, the NA levels in hippocampus of group B changed significantly during the whole anesthesia course, with the highest release being (0.19¡À0.02) ¦Ìg/15 min and the lowest release being (0.13¡À0.03) ¦Ìg/15 min. The NA levels in group A changed steadily [from (0.16¡À0.01) ¦Ìg/15 min to (0.14¡À0.02) ¦Ìg/15 min], (P<0.05). CONCLUSION: Propofol anesthesia can inhibit the NA release in hippocampus but yohimbine increases NA release in hippocampus in propofol anesthesia. ......