Objective To investigate the influence and mechanism of acupuncture at the points in Heel Vessel for the circadian clock genes of Period(Per)1 and Per 2 mRNAs in the suprachiasmatic nucleus(SCN)in insomnia rats.Methods Thirty male SD rats were randomly divided into blank

model

acupuncture groups

10 rats in each group.Insomnia model was established by intraperitoneal injection of PCPA(suspension

1 mL/100 g).Acupuncture at"Shenmai"(BL 62)and "Zhaohai"(KI 6)was used in the acupuncture group for continuous 7 days

15 min/day and once daily.The circadian rhythm was observed;the expressions of Per 1 and Per 2 mRNAs in SCN were examined with real time-PCR.Results The activity in the model group in rest period everyday increased compared with that in the blank group

and the expressions of Per 1 and Per 2 mRNAs in SCN decreased(P<0.05).Compared with the model group

the activity in the acupuncture group in rest period decreased and the expressions of Per 1 and Per 2 mRNAs in the SCN increased(P<0.05).Conclusion Acupuncture at BL 62 and KI 6 can increase the expressions of Per 1 and Per 2 mRNAs in the SCN

so as to decrease the activity in rest period

and improve the quality of sleep in insomnia rats.