RESUMEN
Objective To study the adverse effect of mercury on the tibial nerves of rats. Methods Seventy SD rats (35 females, 35 males, weighed 160-200 g) were randomly divided into 4 groups. 40 rats in group 1 were used to test the acute toxicity of HgCl2, 10 rats in group 2 were given HgCl2 by gavage at 17 mg/kg(1/4 LD50) daily, in group 3 the dose was 8.5 mg/kg(1/8 LD50), 10 rats in group 4 were treated with 0.9% saline 2 ml by gavage daily, the experimental duration was (20?4) days. When the model had been developed, all the male rats were killed and the female rats in group 2 and 3 were given the chelator(DMPS) by intraperitoneal injection at 28 mg/kg for 2 periods of treatment, then were killed and the tibial nerves were examined with the electronic microscope. Results The oral LD50 of HgCl2 was 68.1 mg/kg. Seven rats in group 2 (7/10) were poisoned and two of them got pain manifestation. Six rats in group 3(6/10) were poisoned. Myelinoclasis and the changed axons were found in the tibial nerves of poisoned rats and it was more serious in the rats with pain. The chelator(DMPS) did not relieve the change. Conclusion Sub-acute poisoning of HgCl2 can induce degeneration of tibial nerves in SD rats .
RESUMEN
Objective To investigate the effect of HgCl2 and drugs on the expression of calcitonin gene related peptide(CGRP) in the spinal cord and dorsal root ganglion(DRG).Methods Forty male SD rats(180-220 g) were randomly divided into 7 groups,5 in each treated group,10 in the control.Group A(high HgCl2),B(high HgCl2 +DMPS),C(high HgCl2+DMPS+ carbamzepine) were administrated with HgCl2 at the dose of 17 mg/kg(1/4 LD50),group D(low HgCl2),E(low HgCl2+DMPS),F(low HgCl2+NS) at the dose of 8.5 mg/kg(1/8 LD50),by gavage,once a day,the control group treated with normal saline(NS) in the same way.The sub-acute mercury poisoning models were developed within 18-22 days.Then five rats of control group and group A and D were killed and group B and E were treated with the chelator(DMPS) by intraperitoneal injection at the dose of 28 mg/kg for 2 periods.Group C was given DMPS+ carbamzepine and group F was given NS only.The carbamzepine was used at the dose of 16.82 mg/kg by gavage daily for 14 days.The spinal cord(L5-6) and the DRG of L5 and L6 were collected after the treatment finished.The immunohistochemistry SABC way was used to detect CGRP.Results The CGRP level in spinal cord and DRG of the rats exposed to HgCl2 increased significantly compared with the control group(P