两种药物对氯化汞染毒大鼠脊髓及背根神经节P物质的影响

目的观察两种药物对氯化汞染毒大鼠脊髓和背根神经节（DRG）P物质（SP）的影响。方法雄性sD大鼠40只，分为7组。对照组（10只）经口灌胃生理盐水（NS）2ml／次，每天1次；A、B、C组（各5只）按17mg／kg；D、E、F组（各5只）按8．5mg／kg经口灌胃HgCl2溶液，每天1次。7组均连续灌胃（20＋2）d。处死A、D组大鼠和对照组5只大鼠，随后B、E组用二巯丙磺钠注射液（DMPS）按28mg／kg腹腔注射驱汞两疗程；C组用DMPS（28mg／kg）＋卡马西平（按16．82mg／kg经口灌胃qd×14d）；F组腹腔注射NS1ml／次。实验结束后处死全部动物，灌注固定取出脊髓L5-6节及L5、L6两侧DRG并制成病理切片。用免疫组化SABC法测定DRG和脊髓SP表达水平。结果染汞组大鼠DRG和脊髓SP平均灰度均显著低于对照组；平均面积均显著高于对照组（P〈0．05）；B、E组用DMPS驱汞两疗程及F组腹腔注射NS两周期后均未见SP表达显著减弱，C组用DMPS＋卡马西平显著降低DRG和脊髓SP平均面积，提高平均灰度（P〈0．05）。结论亚急性氯化汞染毒大鼠DRG和脊髓SP水平显著增高，卡马西平联合DMPS能够有效抑制SP表达。

Effect of Two Drugs on Substance Expression in Spinal Cord and DRG of Rat Exposed to Mercury Chloride

Objective To investigate the effect of two drugs on substance P （SP） expression in spinal cord and dorsal root ganglion（DRG） of rats exposed by mercury chloride（HgCl2）. Methods Fourty SD rats （male, weight 180-220g） were divided into 7 groups. Group A,B,C （5 rats,respectively）were exposed by HgCI2 solution at dose of 17 mg/kg（1/4 LD50） and group D,E,F（5 rats, respectively）were exposed bu HgCl2 solution at dose of 8.5 mg/kg（1/8 LD50） by gavage daily. Control group （10 rats） received nomal saline （NS） 2 ml by gavage daily. The seven group rat were treated by gavage daily for （20±2） days.Then five rats of control group and group A and D were dissected and the chelator（DMPS） was injected into the abdomen of alive rats of group B and E at dose of 28 mg/kg for 2 period of treatment. Group C was given DMPS （28 mg/kg） carbamzepine （16.82 mg/kg） and group F was injected NS 1 ml into the abdomen of rats only. The rats were all dissected and the spinal cord （L5-6） and the DRG of L5 and L6 were taken. Then the pathological examinations were made and SP expression of spinal cord and DRG were detected by immunohistochemistry SABC way. Results He SP levels in spinal cord and DRG of the rats exposed to HgCl2 were significantly increased when compared with control group （P 〈 0.05）. SP expression of group F, B and E were significantly decreased when compared with control group.The SP levels of group C in spinal cord and DRG were significantly decreased after 2 periods of treatment when compared with group B （P 〈 0.05 ）. Conclusion P level of spinal cord and DRG of rats exposed by mercury chloride could be inceased and could be inhibited by carbamzepine combined with DMPS.