Effect of dexmedetomidine on long-term cognitive function after partial hepatectomy in mice / 临床麻醉学杂志

ABSTRACT

Objective To investigate the effect of dexmedetomidine (Dex)on long-term cogni-tive function after partial hepatectomy (PH)in mice.Methods Forty adult male C57BL/6J mice were randomly divided into control group (group C),group PH,normal saline group (group NS)and group Dex,10 mice per each group.At 2 days after PH,the mice of group C and group PH under-went Morris water maze test,four times per day and a total of 4 days.The mice were euthanized and hippocampi tissue was immediately excised for determination of wet hippocampi weight to dry hipp-ocampi weight (W/D)and total hippocampi water content (TWC).The expression levels of cycteinyl aspirate-specific protease 12 (caspase-12)mRNA and protein of hippocampi tissue were detected re-spectively by reverse transcription-polymerase chain reaction (RT-PCR)and Western blot.Apoptosis index (AI)of hippocampi tissue was determined by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL)assay.After the mice regained consciousness after operation,animals re-ceived intraperitoneally Dex at a dose of 25 μg·kg-1 ·d-1 for 30 consecutive days in group Dex.Ani-mals of group NS were given intraperitoneally with the same volume of normal saline.After treatment for 30 consecutive days,the mice of group Dex and group NS underwent Morris water maze test,four times per day and a total of 4 days.The mice were euthanized and hippocampi tissue was immediately excised for determination of W/D and TWC.The expression levels of caspase-12 mRNA and protein of hippocampi tissue were detected respectively by RT-PCR and Western blot.AI of hippocampi tissue was determined by TUNEL assay.Results Compared with the first day,the escape latency at the third day,the fourth day and swimming distance were shortened in groups C,NS and Dex (P <0.05);Compared with group C,the escape latency at the third day,the fourth day and swimming distance were prolonged (P < 0.05 ), W/D,TWC and AI were higher (P < 0.05 ), and the expression levels of caspase-12 mRNA and protein of hippocampi tissue were significantly higher (P<0.05)in group PH.Compared with group NS,the escape latency at the third day,the fourth day and swimming distance were shortened (P <0.05),W/D,TWC and AI were lower (P <0.05)and the expression levels of caspase-12 mRNA and protein of hippocampi tissue were significantly lower (P <0.05)in group Dex.Conclusion The treatment of Dex could improve the long-term cognitive function after PH in mice,and the mechanism may be to lighten apoptosis mediated by caspase-12 in hippocampi tissue.