Objective To observe the effect of acupuncture and moxibustion of the combined “Biao-Ben” acupoints on autonomic nervous function and related factors in rats with irritable bowel syndrome diarrhea(IBS-D). Methods Female SD rats were randomly divided into normal control

IBS-D model

“Biao-Ben” acupoint combination

and conventional acupoint combination groups

with 10 rats in each group. The IBS-D model was established by repeated chronic stress stimulation(water or food deprivation

painful tail pinching

exposure to a 43 ℃ environment

forced swimming in 4 ℃ water

day-night inversion and horizontal vibration) for 28 d

and followed by acute restraint stress(wrapping of shoulders

forelimbs and trunk) for 1 h and gavage of senna fluid

once daily for 28 d. For rats of the “Biao-Ben” acupoint combination group

acupuncture and moxibustion were applied to “Guanyuan”(CV4)

bilateral “Zusanli”(ST36)

and “Neiguan”(PC6)

and for rats of the conventional acupoint combination group

acupuncture and moxibustion were applied to bilateral ST36

“Tianshu”(ST25)

and “Shangjuxu”(ST37). Both acupuncture and suspension moxibustion treatment were conduced for 15 min

once daily for 21 days. The fecal water content was calculated

and the spontaneous activity behaviors(total distance of crossing and the number of squares crossed in 5 min) were evaluated by open-field tests. The abdominal withdrawal reflex(AWR) was detected. H.E. staining was used to observe the histopathological changes of colon tissue. The domains of heart rate variability(HRV) including low frequency(LF)

high frequency(HF)

and LF/HF were analyzed using an electrophysiological recorder. The contents of calcitonin gene-related peptide(CGRP) in serum and noradrenaline(NE) in plasma were detected using ELISA. The expression level and immunoactivity of 5-hydroxytryptamine(5-HT) in colon tissues were detected by Western blot and immunofluorescence histochemistry

separately. Results Compared with the normal group

the model group had a striking increase in fecal water content

AWR scores at 20

40

60

and 80 mm Hg

NE and CGRP contents

LF

LF/HF

and 5-HT protein expression and immunoactivity(P<0.01)

and an obvious decrease in the total distance of crossing

the number of squares crossed

and HF of HRV(P<0.01). In comparison with the model group

the fecal water content

AWR scores at 20

40

60

and 80 mm Hg

NE and CGRP contents

LF

LF/HF

and 5-HT protein expression and immunoactivity were significantly decreased(P<0.01

P<0.05)

while the total distance of cros-sing

number of squares crossed

HF of HRV were considerably increased(P<0.01

P<0.05) in both “Biao-Ben” acupoint combination and conventional acupoint combination groups. The effects of the “Biao-Ben” acupoint combination were apparently superior to those of conventional acupoint combination in down-regulating the fecal water content

AWR score at 20

40

60 and 80 mm Hg

NE and CGRP contents

LF

LF/HF

and 5-HT expression and immunoactivity

and in increasing the number of squares crossed

and HF of HRV(P<0.01

P<0.05). HE staining showed no pathological changes in colonic mucosa in all groups. Conclusion Acupuncture and moxibustion stimulation of combined “Biao-Ben” acupoints can effectively improve the symptoms(spontaneous activities

visceral hypersensitivity) of IBS-D model rats

which may be related to its functions in regulating autonomic nervous activities

and down-regulating blood NE and CGRP contents and colonic 5-HT protein expression and immunoactivity

and the effects of “Biao-Ben” acupoint combination are superior to those of conventional acupoint combination.