Objective To observe the effect of chronological moxibustion on plasma corticosterone(CORT)

corticotrophin releasing factor(CRF)and adrenocorticotropic hormone(ACTH)levels in rheumatoid arthritis(RA)rats

so as to explore its mechanisms underlying improvement of RA.Methods A total of 144 SD rats were randomly divided into normal control

model

moxibustion

sham-adrenalectomy(ADX

sham-ADX)

ADX and ADX+moxibustion groups which were further separately divided into 4subgroups(4time-points:12pm

6am

12 am

6pm

n=6/subgroup).The RA model was established by subcutaneous injection of Freund's complete adjuvant(FCA

0.1mL)into the right footpad(for rats of the latter 5groups).In rats of the ADX and ADX+moxibustion groups

bilateral adrenal glands were removed under anesthesia.Moxibustion was applied to unilateral"Shenshu"(BL 23)and"Zusanli"(ST 36)for 10 min

once daily for 6days in a week

and continuously for 3weeks.The paw swelling volume was measured and plasma CORT

ACTH and CRF contents were assayed by ELISA and the circadian rhythm was analyzed by cosine curve fitting(cosinor)method.Results The paw swelling volume was significantly increased in the model group than in the normal control group(P<0.05)

and decreased remarkably in the moxibustion group(P<0.05).The paw volume was markedly increased in the ADX+moxibustion group in comparison with the moxibustion group(P<0.05).In intact rats

plasma CRF and ACTH contents were significantly increased(P<0.05)

and plasma CORT was obviously decreased in the model group(P<0.05).After moxibustion

the increased plasma CRF and ACTH contents and the decreased plasma CORT level were considerably reversed(P<0.05).In ADX rats

plasma CRF

ACTH and CORT contents of ADX and ADX+moxibustion groups had no significant changes compared with the sham-ADX group(P>0.05).Results of the cosine curve fitting analysis showed that the peak phases of plasma CORT contents were-355.78°at about 23:43in the normal control group

-309.05°at about 20:36in the model group

-326.50°at about 21:46in the moxibustion group

-291.65°at about 19:27in the ADX group and-300.87°at about 20:31in the ADX+moxibustion group.The peak phases of plasma ACTH contents were-324.08°at about 21:37in the normal control group

-295.39°at about 19:41in the model group

-310.81°at about 20:43in the moxibustion group

-146.51°at about 9:46in the ADX group and-267.64°at about 17:50in the ADX+moxibustion group.The peak phases of plasma CRF contents were-257.47°at about 17:10in the normal control group

-184.74°at about 12:19in the model group

-263.00°at about 17:32in the moxibustion group

-202.46°at about 13:30in the ADX group and-232.84°at about 15:31in the ADX+moxibustion group.It suggests that in the intact RA rats

moxibustion intervention may inhibit modeling-induced decrease of the circadian rhythm of plasma CORT

and hyperactivity of ACTH and CRF circadian rhythm.ConclusionMoxibustion intervention can relieve paw swelling in RA rats and modulate the circadian rhythm activities of plasma CORT

ACTH and CRF levels(HPA axis activities)in intact animals.