The expression of MMP-9 and TIMP-1 in the sciatic nerve of rats with hypertension complicated diabetic peripheral neuropathy

Objective To investigate the expression of MMP-9mRNA and TIMP-1mRNA in the sciatic nerve of rats with hypertension(HTN) complicated diabetic peripheral neuropathy(DPN). Methods The rats were randomly divided into normal group, HTN group, DPN group and HTN+DPN group. 4 weeks after modeling, the blood sugar, blood pressure and conduction velocity of sciatic nerve were measured, the expression of MMP-9mRNA and TIMP-1mRNA in the sciatic nerve was detected by RT-PCR. Results Compared with normal group and HTN group, the content of blood sugar was increased, while the conduction velocity of sciatic nerve was decreased, the expression levels of MMP-9 mRNA and TIMP-1mRNA in sciatic nerve were increased in DPN group and HTN+DPN group( 0.01). Compared with DPN group,the content of blood pressure was increased, and the conduction velocity of sciatic nerve was decreased, the expression level of MMP-9 mRNA in sciatic nerve was increased and the expression level of TIMP-1 mRNA in sciatic nerve was decreased in HTN+DPN group( 0.01). Conclusion Upregulation of MMP-9 and downregulation of TIMP-1 in sciatic nerve of hypertension complicated diabetic peripheral neuropathy might be related to the inhibition of Schwann cells and myelination leading to the damage of peripheral nerves.