The Study On The Possibility Of The Stomachache Analgesia With Lidocain Injected Into The Referred Area

Objective: (1) In order to investigate the referred area after the stomachache with Formalin; (2) To study the effect of lidocain injected into referred area on the treatment of the stomachache; (3) To discuss the possibility and the mechanisms of the stomachache treatment by injecting lidocain into referred area.Methods and Results: (1) Determination of the referred area: Ten minutes after the Evans Blue Dye injection into blood vessel. Formalin was injected into stomach. Two hours later, the number of the blue dots of cutaneous plasma extravasation in the skin was counted. It was found that the blue dots were mainly in the dorsal T6-T10 paravertebral area, and the number of the blue dots was significantly(p<0.05) increased over the part out of the T6-T10 paravertebral area; (2) Expression of c-fos and SP: Two hours after the nociceptive stimulus with Formalin to cause stomachache, it was found that the Fos like immunoreactive(FLI) neurons were mainly in the lamina â… ,â…¡,â…£,â…¤,â…¥ and â…©of thoracic spinal cord, in the medullary nucleus of the solitrary tract(NTS) and the neurons of the pons parabrachial(PBN);SP like immunoreactive(SP-LI) was mainly in the lamina â… ,â…¡ of the thoracic spinal cord; (3) After injecting lidocain into referred area: the number of FLI neurons: T group is significantly decreased than that in the other experimental groups(p<0.05) in the spinal cord(â… -â…¥).There isn't any difference among groups in the NTS and PBN. Relative densities of SP-LI in the superficial layers of the spinal dorsal horn (T group) show a tendency to decrease, but there isn't any difference among experimental groups.Conclusion: (1) It is suggested that the area of referred pain during stomachache with Formalin is in the skin of the dorsal T6-T10 paravertebral area of the rat in all probability; (2) After stomachache with Formalin , there are plenty of neurons of Fos-LI in spinal dorsal horn,NTS and PBN; Relative densities of SP-LI in the superficial layers of the spinal dorsal horn is increased; (3) Lidocain injected into referred area could decrease the number of the FLI neurons in spinal cord(â… -â…¥); Relative densities of SP-LI in the superficial layers of the spinal dorsal horn show a tendency to decrease, but there isn't any difference among groups. It is suggested that there is a possibility of injecting lidocain into referred area for stomachache treatment.