RESUMEN
OBJECTIVE: To observe and compare the effect of electroacupuncture (EA) of "Tianshu" (ST25) and "Dachangshu" (BL25) on intestinal sensitivity and the expression of M3 muscarinic acetylcholine receptor (M3R) and 5-hydroxytryptamine 3A receptor (5-HT3AR) in the colon tissue in irritable bowel syndrome (IBS) rats, so as to explore its mechanism underlying improvement of IBS. METHODS: Forty newborn Wistar rats were randomly divided into blank control, model, ST25 and BL25 groups (n＝10 rats per group). The IBS model was established by joint application of maternal separation, acetic acid enema plus colorectal distension from day 8 to 21 after birth. At the age of 9 weeks, EA (2 Hz/100 Hz, 0.1－0.3 mA) was applied to ST25 and BL25 for 20 min, once every other day for 5 times. The modified method was used to record the abdominal withdrawal reflex (AWR), so as to evaluate the visceral sensitivity by referring to the modified Al-Chaer's and colleagues' methods. The threshold (initial wave), the number and peak-peak value of contraction waves (AWR) within 90 s were recorded. The immunoactivity of M3R and 5-HT3AR in the colon tissue was detected by immunohistochemistry. RESULTS: After modeling, the latency was obviously shortened, the number and peak-peak values of contraction waves of intestine were significantly increased, and the immunoactivity of M3R and 5-HT3AR was notably up-regulated in the model group compared with the blank control group (P<0.01). After the EA intervention, the latency was obviously prolonged, the peak-peak value in both ST25 and BL25 groups, and the number of contraction waves in the ST25 group were significantly decreased (P<0.01), and the expression levels of M3 and 5-HT3A R were considerably down-regulated in both ST25 and BL25 groups relevant to the model group (P<0.01). The therapeutic effects were significantly better in the ST25 group than in the BL25 group in prolonging the latency and reducing the contraction wave number, and in down-regulating the expression of colonic M3R and 5-HT3AR (P<0.05, P<0.01). CONCLUSION: EA at ST25 and BL25 can reduce the intestinal sensitivity in IBS rats, which is probably associated with its effects in down-regulating the expression of M3R and 5-HT3AR in the colon. The therapeutic effects of ST25 were obviously better than those of BL25 in suppressing intestinal sensitivity and expression of colonic M3R and 5-HT3AR.
RESUMEN
This study was aimed to elucidate the 5-HT3R molecular mechanism of Radix Paeoniae Albaextract (RPAE) as drug intervention in the treatment of premenstrual syndrome (PMS) model rats with liver-qi depression pattern.PMS model rats with liver-qi depression pattern were prepared.And then,the model was treated with RPAE.The protein distribution of 5-HT3AR and 5-HT3BR in the frontal lobe was evaluated by the immune fluorescence technology and western blot.The results showed that there were positive expressions of 5-HT3AR and 5-HT3BR in frontal lobe of rats in each group.Compared with the normal group,the 5-HT3AR and 5-HT3BR protein expression levels of the frontal lobe in the model group increased significantly (P < 0.05).Compared with the model group,the 5-HT3AR protein expression level in the frontal lobe decreased significantly after RPAE treatment (P < 0.05).In conclusion,RPAE regulated the protein expressions of 5-HT3AR and 5-HT3BR in frontal lobe,which may be one of the mechanisms for its treatment of PMS with liver-qi depression pattern.