Compared with those of the control group, mechanical PWT and PWTL of rats in the DNP, DNP + SN50, DNP + MIP, DNP + LPS-RS, DNP + baclofen, and DNP + saclofen groups were significantly decreased at 14 days and 21 days.
Effects of TLR4/NF-[kappa]B Signal Pathway Inhibition on Mechanical PWT and PWTL. In the DNP + LPS-RS and DNP + MIP groups, inhibition of TLR4 with LPS-RS ultrapure or Myd88 with MIP significantly increased mechanical PWT and PWTL compared with those in the DNP group (saline) at 1, 2, and 3 days after i.t.
Effects of [GABA.sub.B] Receptor Activation or Inhibition on Mechanical PWT and PWTL. In the DNP + baclofen group, activation of [GABA.sub.B] receptors with baclofen significantly increased mechanical PWT and PWTL compared with those in the DNP group (saline) at 1,2, and 3 days after i.t.
In this study, we observed the upregulation of TLR4, Myd88, NF-[kappa]Bp65, IL-1, and TNF-[alpha] expression in the spinal cord in DNP rats, accompanied by significantly decreased PWT and PWTL compared with normal rats.
In the DNP + saclofen group, PWT and PWTL decreased and the expression of TLR4, MyD88, NFKBp65, and downstream IL-1 and TNF-[alpha] in the spinal cord was upregulated compared with those in the control DNP group.
The PWTL and MWT of bilateral plantar in rats were determined by 3 times with 6-8 min interval, and the averages were recorded as results.
PWTL measured 30 minutes later, to determine MWT of the bilateral plantar on rats and express as L and R (units are gram).
The pain threshold in rats is unqualified (R/L values of double lower limbs >1.2 or <0.8 and PWTL <5s or >30 s).
The PWTL and MWT were significantly lower and had operation hind paw adduction or slight valgus, walking weakness, and gait slight limp.