OBJECTIVE: To observe the distribution characteristics of sensitization areas on the body surface in the rat models with functional constipation and diarrhea, explore the regulatory patterns of electroacupuncture (EA) of different intensities at "Tianshu" (ST25) on distal colon motility, and clarify the roles of the neurons of different subtypes in the enteric nervous system (ENS) displayed in the regulatory effect. METHODS: Of 90 SD male rats of SPF grade, 15 rats were randomized into a normal group, a constipation group and a diarrhea group, 5 rats in each one. The stool form and fecal water content, as well as the distribution of the Evans blue (EB) extravasation on the body surface after the intravenous injection with EB on the tails were observed. Eighteen rats were randomized into a normal +2 mA group, a normal +4 mA group and a normal + 6 mA group, 6 rats in each one. Using physiological signal acquisition system, the area under the curve and the average amplitude of colon peristalsis were recorded and analyzed, and the immediate effect on distal colon peristalsis observed after EA with different intensities at "Tianshu" (ST25). Thirty rats were randomized into a normal group, a constipation group, a diarrhea group, a constipation +2 mA group, and a diarrhea +6 mA group, 6 rats in each one, so as to observe the cumulative effect on colon motility disorder in the rat models of constipation and diarrhea after EA at "Tianshu" (ST25). Twelve rats were randomized into a constipation +2 mA group and a diarrhea +6 mA group, 6 rats in each one, to observe the immediate effect on colon motility disorder in the rat models of constipation and diarrhea after EA at "Tianshu" (ST25). Fifteen rats were randomly divided into a normal group, a constipation group, a diarrhea group, a constipation +2 mA group, and a diarrhea + 6 mA group, 3 rats in each one. Using the whole-mount staining technique, the expression of vesicular acetylcholine transporter (VAChT)-positive neurons and nitric oxide synthase (nNOS)-positive neurons in ENS was detected. According to the group divisions, the functional constipation models were established by intragastric administration of loperamide hydrochloride (10 mg/kg, once daily, for consecutive 7 days), and the functional diarrhea models were prepared by intragastric administration of folium sennae decoction (10 mL/kg, once daily, for consecutive 2 days). The interventions were delivered with EA of different intensities (the electric current of 2, 4 or 6 mA) at bilateral "Tianshu" (ST25), separately, with the continuous wave and the frequency of 10 Hz used. RESULTS: Compared with the normal group, the fecal amount was decreased, and the fecal water content was reduced in the rats of the constipation group (P<0.001); and loose stool was presented and the fecal water content increased in rats of the diarrhea group (P<0.001). EB extravasation on the body surface happened in the region from T₆ to S₂ of the rats in the constipation and diarrhea groups, and it was more concentrated in the lower abdominal and the lower back regions from T₁₀ to L₃. Compared with the indexes before EA, in the normal +2 mA group and the normal +4 mA group, the areas under the curve and the average amplitude of the distal colon peristalsis were higher during EA delivery (P<0.01, P<0.05), showing a stimulatory immediate effect; and the post-effect was obtained after EA at 2 mA. Whereas, these two indexes were declined during EA in the rats of the normal +6 mA group (P<0.001), showing an inhibitory immediate effect. After many interventions with EA, when compared with those before EA, the above two indexes rose in the constipation +2 mA group (P<0.05, P<0.01), and they were dropped in the diarrhea +6 mA group (P<0.01, P<0.05). The area under the curve of the colon peristalsis in the constipation +2 mA group was higher than that of the constipation group (P<0.001), and that in the diarrhea +6 mA group was lower compared with that in the diarrhea group (P<0.001). The stimulatory effect of EA on colon motility in the constipation +2 mA group was stronger than that of the normal + 2 mA group (P<0.05), and its inhibitory effect was not different statistically in comparison between the normal +6 mA group and the diarrhea +6 mA group (P>0.05). In ENS of the distal colon, after EA at 2 mA, the proportion of VAChT-positive neurons was higher than that of the activated nNOS-positive neurons (P<0.001); and after EA at 6 mA, the activated nNOS-positive neurons were dominant (P<0.001). CONCLUSION In the functional constipation and diarrhea rat models, the sensitization areas on the body surface are centralized in the lower abdominal and the lower back regions of T₁₀ to L₃. Electroacupuncture at "Tianshu" (ST25) has a bidirectional regulatory effect on distal colon motility, and this effect is coordinated with the intensity of electroacupuncture, and may be mediated by ENS neurons of different subtypes.
Animals ; Electroacupuncture ; Male ; Rats ; Colon/innervation* ; Acupuncture Points ; Rats, Sprague-Dawley ; Constipation/physiopathology* ; Gastrointestinal Motility ; Humans ; Diarrhea/physiopathology*

ObjectiveTo observe the effects of electroacupuncture at Zhongwan （CV12） on gastric nociceptive response induced by gastric acid stimulation and explore the underlying mechanisms associated with nuclei of the medullary viscerosensory and visceral motor neurons. MethodsTwenty SD rats were given intragastric administration of 0.5 mol/L diluted hydrochloric acid （0.5 ml/100 g） to induce gastric nociceptive response induction. Eight rats were randomly selected to record the gastric slow wave （GSW） area under the curve， and extracellular discharge frequency of neurons in the nucleus of the solitary tract （NTS） and dorsal motor nucleus of the vagus nerve （DMV） before intragastric administration and at 1， 5， 10， 15， 20， 25， 30， 35， 40， 45， 50， 55， and 60 minutes after intragastric administration. The remaining 12 rats received electroacupuncture intervention at Zhongwan within 5 to 25 minutes after intragastric administration of diluted hydrochloric acid， with a duration of one minute. The GSW area under the curve and extracellular discharge frequency of NTS and DMV neurons were compared between the 1-minute intervals before and after electroacupuncture intervention. ResultsCompared to the baseline before intragastric administration， the area under the curve of GSW significantly increased at 1， 5， 10， 15， 20， and 25 minutes after intragastric administration， and the extracellular discharge frequency of excitatory neurons in the NTS （accounting for 90%， 57/63） significantly increased at 1， 5， 10， 15， 20， 25， 30， 35， and 40 minutes， both reaching peak values at 1 minute after intragastric administration （P＜0.01 or P＜0.05）. The extracellular discharge frequency of inhibitory neurons in the DMV （accounting for 91%， 20/22） showed a non-significant increase at 1 minute after intragastric administration （P＞0.05）， but significantly decreased at other timepoints （P＜0.05）. Compared to the baseline before electroacupuncture intervention， the GSW area under the curve and the extracellular discharge frequency of excitatory neurons in the NTS significantly decreased （P＜0.05）， while the extracellular discharge frequency of inhibitory neurons in the DMV showed no significant difference （P＞0.05）. ConclusionElectroacupuncture at Zhongwan can improve gastric nociceptive response induced by gastric acid stimulation， possibly by reducing the transmission of visceral sensation and decreasing the excitability of NTS neurons in the medulla.

OBJECTIVETo judge whether algesia sensitization of some acupoints is existed and whether the acupoint algesia sensitization area is expanded in the patients of intestinal cancer.

METHODSTotally, 30 patients of intestinal cancer and 30 healthy subjects were included. The electronic Von Fray was used to determine the pressure-pain thresholds at 13 acupoints relevant with gastrointestinal disorders and the reference points at the sites 1and 2lateral to those points as well as the sites at the corresponding nerve segments. Compared with the pressure-pain thresholds at the reference points of the different segments, the relative value was calculated. The changes were analyzed in the pressure-pain thresholds at the relevant acupoints on the body surface in the patients of intestinal cancer as compared with the relative pressure-pain thresholds in the healthy volunteers.

RESULTSThe pressure-pain thresholds at Zusanli (ST 36), Shangjuxu (ST 37), Xiajuxu (ST 39), Quchi (LI 11) and Dachangshu (BL 25) in the patients of intestinal cancer were all significantly reduced as compared with those of the healthy subjects (<0.05,<0.01,<0.001). At the non-acupoint sites 1and 2lateral to those acupoints as well as at the sites of the same segments, the pressure-pain thresholds were reduced significantly as compared with the control group (<0.05,<0.01,<0.001). Particularly, the sensitization zone of Yinlingquan (SP 9) focused on the acupoint, the site 1lateral to it as well as the non-acupoint sites of the same segments (<0.01,<0.001).

CONCLUSIONThe acupoint sensitization is displayed at Zusanli (ST 36), Shangjuxu (ST 37), Xiajuxu (ST 39), Quchi (LI 11), Dachangshu (BL 25) and Yinlingquan (SP 9) and the sensitization area is expended in the patients of intestinal cancer.

Objective To analyze the survival curves of ASIC3 -/-and TRPV1 -/-mice, and provide a reference for further breeding of these strains of mice.Methods Forty-four ASIC3 -/-mice and sixty-one TRPV1 -/-mice were included in this study.The survival of the mice was observed in normal feeding for 500 days, survival curves were drawn, and their survival was analyzed.Results With the passing of time, the survival probability was decreased in ASIC3 -/-mice and TRPV1 -/-mice.The survival probability of TRPV1 -/-mice was significantly better than that of ASIC3 -/-mice (P =0.004, P <0.01).No significant difference was observed between the males and females of the same strain. Conclusions The survival probability of TRPV1 -/-mice is better than that of ASIC3 -/-mice.There is no significant gender difference in the two strains of mice.