Abstract: Objective To study inhibitory effect of quercetin on hypertrophy of rat proximal tubule epithelial cells(PTECs)induced by high glucose and the mechanism of the effect.Methods The manual micro-separation was used to culture rats' original PTECs,and then the PTECs were separated into five groups:control group,high glucose group,low-,medium-,and high-dose quercetin groups.The cell volume,³H-leucine incorporation and protein content were measured after 72 hours' treatment.The activity of Na⁺,K⁺-ATPase was measured with liquid scintillation technique.The expression of motocyte chemoattractant protein-1(MCP-1)was measured with Western blot.The intercellular adhesion molecule-1(ICAM-1),interleukin-1β(IL-1β),mannose binding lectin(MBL)in culture supernatant were measured with enzyme-linked immunosorbent assay.Results Compared with those of the high glucose group,significantly decreases were observed in the cell volume(113.33±2.44 and 114.71±2.55),cellular protein content(5.03±0.21 and 4.35±0.24 μg/10⁵ cells),cellular Na⁺,K⁺-ATPase activity (2 489.76±218.54 and 2311.55±209.63 μmol/g/L),cellular expression of MCP-1(0.37±0.02 and 0.39±0.02),and the culture supernatant contents of ICAM-1(11.25±2.71 and 11.12±2.56μg/g),IL-1β(97.21±12.26 and 96.11±10.53μg/g)and MBL(16.87±3.79 and 15.63±3.78μg/g) for the PTECs of medium- and high-dose quercetin groups(P <0.05 for all).Conclusion Quercetin has an apparent inhibitory effect on hypertrophy of PTECs induced by high glucose and the mechanism of the effect may be related to the inhibition of inflammation factors and stabilization of Na⁺,K⁺-ATPase activity under high sugar environment.