Changes in expression of hepatic circadian clock gene in different types of circadian rhythm and effect of isoflurane anesthesia on expression of hepatic circadian clock gene in mice / 中华麻醉学杂志

ABSTRACT

Objective To investigate the changes in the expression of hepatic circadian clock gene in different types of circadian rhythm and the effect of isoflurane anesthesia on the expression of hepatic circadian clwk gene in mice.Methods Seventy-two male C57/B6 mice,aged 2 months,weighing 20-25 g,were randomly divided into 3 groups (n =24 each)normal light/dark (LD) cycle group,reversal LD cycle group and anesthesia group.Normal LD cycle group and anesthesia groupwere maintained in a regular 12 h LD cycle with lights on at 800 am and off at 800 pm for 3 weeks,and in addition anesthesia was then performed with isoflurane in anesthesia group.Reversal LD cycle group was kept in an inverted12 h LD cycle with lights on at 800 pm and off at 800 am for 3 weeks.The natural time was converted to circadian time (CT) and the initial time was set at CT0.Isoflurane anesthesia group was exposed to 2％ isoflurane for 6 h during the wakening period from CT14 to CT20.The liver and suprachiasmatic nucleus (SCN) were removed from mice at CT2,CT8,CT14 and CT20 for determination of Clock and Cry1 mRNA expression by real-time quantitative PCR.Results Clock and Cry1 mRNA expression in the liver and SCN showed rhythm in the two different types of circadian rhythm.Compared with that in SCN,the peak phase of Clock and Cry1 mRNA expression in livers was delayed in two different types of circadian rhythm.Isoflurane anesthesia caused a peak phase delay of Cry1 and Clock mRNA expression in livers as compared with normal LD cycle group.Conclusion Circadian clock gene in livers shows rhythmic expression in different types of circadian rhythm,and isoflurane anesthesia can cause a large peak phase delay of circadian clock gene expression in livers of mice.