Analgesic effects of intraarterial injection of imipenem cilastatin sodium in a rat model of knee osteoarthritis.

Abstract

Angiogenesis is involved in the underlying musculoskeletal pain mechanism; therefore, embolization of blood vessels is expected to have an analgesic effect. We investigated the analgesic effect of intraarterial administration of imipenem cilastatin sodium (IPM/CS) in knee osteoarthritis (OA) model rats using behavioral measures and in vivo patch-clamp recording. To develop the knee OA model, monosodium iodoacetate (MIA) was administered to the right knee joint. First, we infused IPM/CS in the right femoral artery and investigated the knee joint mechanical pressure threshold using a digital device. Next, the nociceptive signals originating from the knee were analyzed via the spontaneous excitatory postsynaptic current (sEPSC) record within the neural cells in the dorsal spinal horn using the in vivo patch-clamp approach. In knee OA rats, the mechanical thresholds at the damaged knee were decreased compared with those of the contralateral knee, whereas these thresholds remained stable in the sham group. The pressure threshold of knee OA rats was significantly increased following intraarterial infusion of IPM/CS but not saline. However, the pain thresholds of knee OA rats were unaltered. A notable rise in the average sEPSC frequency was detected in knee OA rats compared with the sham group. The sEPSC decreased in knee OA rats following intraarterial infusion of IPM/CS but not saline. These results indicated that intraarterial infusion of IPM/CS attenuated pain caused by knee OA. Hence, this method could serve as a strategy for pain alleviation in patients with knee osteoarthritis.