Fig. 2. Effect of MCP-1 on brain endothelial barrier function. (A) Confluent CCR2^+/+ or CCR2^–/– mBMEC, were grown on the filters in a Transwells chamber system and TEER measurements made. There were no differences in TEER between the two strains in the absence of MCP-1. However, after exposure to 100 nM MCP-1, the TEER in wild-type mouse cells decreased dramatically while that in CCR2^–/– cells was unaffected. Addition of a neutralizing antibody to MCP-1 partially restored the TEER in CCR2^+/+ mice. (B) Dose response for the effects of MCP-1 on TEER in wild-type cells. (C) The effect of MCP-1 (100 nM) on [¹⁴C]inulin permeability in CCR2^+/+ or CCR2^–/– mice. Results are presented as means ± s.e.m., ^*P<0.001.