OBJECTIVE: To observe the dynamic distribution of the extravasated Evans Blue (EB) dye points at the skin after acute colorectal mucosal injury (AIMI) so as to reveal characteristics of acupoint sensitization. METHODS: Forty adult male SD rats were randomly divided into control (n= 10), AIMI (n=20) and AIMI-recovery (n= 10) groups. According to the reaction state (EB-dye extravasation), each group was further divided into resting state (control), sensitized state (appearance of extravasated EB points), recovery state (disappearance of the extravasated EB points), non-sensitization (NS, no extravasated EB points) state and NS recovery state. The AIMI model was induced by perfusion of 2. 5% mustard oil into the colorectum via a thin tube. Evans blue dye was injected into the caudal vein 4 h after AIMI modeling. The distribution of plasma extravasated EB dye points at the skin of the lower limbs was observed. The C-fiber discharge of the separated ipsilateral sciatic nerve was induced by electrical stimulation of the EB-extravasated acupoints and non-acupoint at the threshold and double-fold threshold using an electric stimulator and recorded using a bicelectric amplifier-computer system. RESULTS: In AIMI rats, the extravasated EB-dye points were found to overlap the "Xiqian" and "Zusanli" (ST 36)-"Shangjuxu"(ST 37) regions. Moreover, the thresholds of C-fiber discharges induced by electrical stimulation of "Xiqian" and "Zusanli" (ST 36)-"Shangluxu"(ST 37) regions were significantly lower than those of the regions without extravasated EB dye acupoint and non-acupoint(P<0. 01, P<0. 05). The numbers of C-fiber discharges evoked by 2-fold threshold electro-stimulation at the "Xiqian" and "Zusanli" (ST 36)-"Shangjuxu" (ST 37) regions were obviously more than those of stimulation of non-acupoint which were experiencing sensitized state(P<0. 01, P<0. 05). CONCLUSION: In rats with acute colorectal mucosal injury, electrical stimulation of the acupoints where the extravasated EB-dye points appear may produce an obvious increase of C-fiber discharges under lower electro-stimulation threshold, suggesting a larger action of the sensitized acupoint.
OBJECTIVE: To observe the dynamic distribution of the extravasated Evans Blue (EB) dye points at the skin after acute colorectal mucosal injury (AIMI) so as to reveal characteristics of acupoint sensitization. METHODS: Forty adult male SD rats were randomly divided into control (n= 10), AIMI (n=20) and AIMI-recovery (n= 10) groups. According to the reaction state (EB-dye extravasation), each group was further divided into resting state (control), sensitized state (appearance of extravasated EB points), recovery state (disappearance of the extravasated EB points), non-sensitization (NS, no extravasated EB points) state and NS recovery state. The AIMI model was induced by perfusion of 2. 5% mustard oil into the colorectum via a thin tube. Evans blue dye was injected into the caudal vein 4 h after AIMI modeling. The distribution of plasma extravasated EB dye points at the skin of the lower limbs was observed. The C-fiber discharge of the separated ipsilateral sciatic nerve was induced by electrical stimulation of the EB-extravasated acupoints and non-acupoint at the threshold and double-fold threshold using an electric stimulator and recorded using a bicelectric amplifier-computer system. RESULTS: In AIMI rats, the extravasated EB-dye points were found to overlap the "Xiqian" and "Zusanli" (ST 36)-"Shangjuxu"(ST 37) regions. Moreover, the thresholds of C-fiber discharges induced by electrical stimulation of "Xiqian" and "Zusanli" (ST 36)-"Shangluxu"(ST 37) regions were significantly lower than those of the regions without extravasated EB dye acupoint and non-acupoint(P<0. 01, P<0. 05). The numbers of C-fiber discharges evoked by 2-fold threshold electro-stimulation at the "Xiqian" and "Zusanli" (ST 36)-"Shangjuxu" (ST 37) regions were obviously more than those of stimulation of non-acupoint which were experiencing sensitized state(P<0. 01, P<0. 05). CONCLUSION: In rats with acute colorectal mucosal injury, electrical stimulation of the acupoints where the extravasated EB-dye points appear may produce an obvious increase of C-fiber discharges under lower electro-stimulation threshold, suggesting a larger action of the sensitized acupoint.