Monocyte chemoattractant protein-1 expression in intimal hyperplasia of vein grafts in a rat model

Abstract

Purpose: Most cardiovascular surgeons prefer artery grafts to vein grafts. Monocyte chemoattractant protein-1 (MCP-1) is the most potent chemoattractant factor for monocytes/macrophages (Mo/Mphi). We conducted experiments based on our hypothesis that intimal hyperplasia (IH) is more severe in vein grafts than in situ artery grafts, due to differences in Mo/Mphi infiltration, and that the expression of MCP-1 is different in vein grafts compared with in situ artery grafts.

Methods: Lewis rats were subjected to either epigastric vein to common femoral artery interposition grafts (VG: n = 34) or common femoral artery reanastomoses (FA: n = 34). IH was defined as the intimal area/total area (intimal ratio, Ri). Immunohistochemistry was also performed, using a monoclonal antibody (ED-1), specific for rat Mo/Mphi. MCP-1 mRNA expression was examined by a reverse transcription-polymerase chain reaction, and compared with S-26 mRNA expression.

Results: After 2 weeks, the Ri of the VGs became significantly larger than the Ri of the FA anastomoses (P < 0.01). ED-1+ cell numbers were significantly elevated in the VG compared with the FA anastomoses, after 1 day, 2 weeks (P < 0.05), and 4 weeks (P < 0.01). MCP-1 mRNA expression was significantly increased in the VGs by 1 day (P < 0.05).

Conclusion: These results show that there could be a direct correlation between the significant increases in MCP-1 mRNA expression, Mo/Mphi infiltration, and the development of IH in vein grafts, not seen in FA anastomoses.