| Objective: to observe and study the effects of electroacupuncture on the sensitivity of chronic visceral hyperalgesia rats and mechanism.Method: Model rats were given noxious colorectal distension once daily on post neonatal days 8-15. Control rats were gaven the same treatment as model rats except colorectal distension. The model rats were freely divided into 5 groups such as simple model group, electroacpuncture group, solvent control group, katenserin group and eletroacunpunture connect with ketanserin group after 8 weeks. Except for simple model group and electroacupunture group, a PE-10 catheter was placed in the subarachonoid space at L5-6 in another 3 groups four days before experiments. On experiment except the simple model group, every group was received homologus treatments 4 times every other day. Electroacupuncture group—electroaupunture at ST36 and the ST37 of double for 30 min; the solvent control group—intrathecally inject 1 percent DMSO 10u1; kentanserin group—intrathecally inject kentanserin 30ug per 10ul. Electroacupuncture connect with ketanserin group—intrathecally inject ketanserin 30ug per 10ul followed cito dispensetur eletroacupuncture. Then the visceral and somatic sensibility evaluations were made by AWR, EMG and TFL. SPSS 11.5 software for Windows was used in the statistical tests; Select control group rats and simple model group descending colon to do patho-ligical examination; Sampled the lumbosacral(L6～S2) and thora- columbar(T13～L2) spinal cord, nucleus raphe magnus, hypothalamus paraventricular nucleus, and cerebral cortex, the semi-quantity analysis of staining density of 5-HT2AR and CGRP-Like Immunoreactivity of these sites were made through immunohisrochemical cstatistical bias and computer image analyzing system.α=0.05 was considered significant in all statistical.Result: The AWR scores and the amplitudes of spike EMG increased gradually with the rising of the CRD pressure. Within the pressure of 20mmHg to 60mmHg, the AWR of simple model group was significantly increased compared with that of the control group. However, at the pressure of 80mmHg, there was no significant difference between two gruops. The amplitudes of spike EMG in every graded CRD pressure are significantly increased compared with that of control group. TFL in simple model group significantly shorten compared with that of control group; There were no obvious histopatholigical changes in descending colon between model rats and control rats. Electroacupuncture can significantly reduced the AWR scores and the amplitudes of spike EMG at same graded pressure of CRD and prolongate TFL compared with that of model rats . The AWR scores, EMG and TFL of the solvent group rats were no significant difference compared with that of the model rats. At the pressure of 20 and 40 mmHg, the AWR of ketanserin group rats was significantly increased compared with that of the the solvent group rats. But at the pressure of 60 and 80mmHg, there was no significant difference between two gruops. However, the amplitudes of spike EMG at every graded pressure significantly increased, TFL was significantly shorten compared with that of the solvent control group. The AWR, EMG and TFL of Ketanserin connect with electroaupuncture was no significant difference compared with that of model rats.Expression of 5HT2AR in TL & LS neurons, hypothalamus paraventricular nucleus decreased, but there were no significant differences between control and CI rats by image analysis. However, image analysis shows that average optial which represents the expression of 5HT2AR in nucleus raphe magnus, cerebral cortex was significantly lower in model rats than those in control rats. Staining density of 5HT2A were significantly decreased in above central neurons except hypothalamus paracentricular nucleus by electroacupuncture.Expression of CGRP in cerebral cortex decreased, but there were no siginificant difference between control and CI rats by image analysis. However, image analysis shows that average optial which represents the expression of CGRP in TL&LS neurons, nucleus raphe magus, hypothalamus paraventricular nucleus significantly lower in model rats than those in control rats. Staining density of CGRP significantly increase in TL & LS neurons, nucleus raphe magnus but significantly decrease in hypothalamus paraventricular nucleus, cerebral cortex by electro- acupuncture.Conclusion: Visceral hyperalgesia could be significantly relieved by electro- acupuncture treatment in model rats. The 5-HT2AR and CGRP in dorsal of TL & LS neurons spinal cord, nucleus raphe magnus, hypothalamus paraven- tricular nucleus and cerebral cortex may take part in the electroacupuncture treatment, but the effects of them could be different.
|
PDF Full Text Request