Background:Nucleoside reverse transcriptase inhibitors (NRTIs) are the earliest and most commonly used anti-human immunodeficiency virus drugs and play an important role in high active antiretroviral therapy.However,NRTI drug therapy can cause peripheral neuropathic pain.In this study,we aimed to investigate the mechanisms of rapamycin on the pain sensitization of model mice by in vivo experiments to explore the effect of mammalian target of rapamycin (mTOR) in the pathogenesis of neuropathic pain caused by NRTIs.Methods:Male Kun Ming (KM) mice weighing 20-22 g were divided into control,2 mg/kg rapamycin,12 mg/kg stavudine,and CMC-Na groups.Drugs were orally administered to mice for 42 consecutive days.The von Frey filament detection and thermal pain tests were conducted on day 7,14,21,28,35,and 42 after drug administration.After the last behavioral tests,immunohistochemistry and west blotting assay were used for the measurement of mTOR and other biomarkers.Multivariate analysis of variance was used.Results:The beneficial effects ofrapamycin on neuropathic pain were attributed to a reduction in mammalian target ofrapamycin sensitive complex 1 (mTORC 1)-positive cells (70.80 ± 2.41 vs.112.30 ± 5.66,F =34.36,P ＜ 0.01) and mTORC 1 activity in the mouse spinal cord.Mechanistic studies revealed that Protein Kinase B (Akt)/mTOR signaling pathway blockade with rapamycin prevented the phosphorylation of mTORC1 in stavudine-intoxicated mice (0.72 ± 0.04 vs.0.86 ± 0.03,F =4.24,P =0.045),as well as decreased the expression of phospho-p70S6K (0.47 ± 0.01 vs.0.68 ± 0.03,F=6.01,P =0.022) and phospho-4EBP1 (0.90 ± 0.04 vs.0.94 ± 0.06,F=0.28,P =0.646).Conclusions:Taken together,these results suggest that stavudine elevates the expression and activity of mTORC1 in the spinal cord through activating the Akt/mTOR signaling pathway.The data also provide evidence that rapamycin might be useful for the treatment of peripheral neuropathic pain.