title: Different Responses of Neointimal Cells to Imatinib Mesylate and Rapamycin Compared with Normal Vascular Smooth Muscle Cells.
abstract: OBJECTIVE
  This study was designed to investigate whether vascular smooth muscle cells (VSMC) from the neointima showed any different response to anti-proliferative agents, such as rapamycin or imatinib mesylate, compared to VSMCs from normal artery.
  
  
  METHODS
  Intimal hyperplasia was made by carotid balloon in jury in male rats. Neointimal cells at 4 weeks after injury and normal VSMCs were extracted by enzymatic isolation method and cultured. Cell viability and proliferation were tested in VSMCs from injured left carotid artery and uninjured right carotid artery. Tests were repeated with rapamycin, imatinib mesylate or both in various concentrations.
  
  
  RESULTS
  Rapamycin decreased cell viability only at a high concentration of 10(-5) M in uninjured VSMCs. Combined drugs decreased cell viability at a lower concentration of 10(-7) M in uninjured VSMCs, and at a higher concentration of 10(-5) M in neointimal cells. Overall, rapamycin showed cytocidal effects at a high concentration of 10(-5) M, whereas imatinib did not. Cell proliferation of neointima was significantly decreased along with the drug concentration. Cell proliferation of uninjured VSMCs was significantly decreased at higher drug concentrations. Combined drug therapy showed synergistic effects. Overall, neointimal cells are more susceptible to the antiproliferative effects of the drugs.
  
  
  CONCLUSIONS
  Neointimal cells from the injured carotid artery are more susceptible to the antiproliferative effect of imatinib and rapamycin. Both drugs can be a used for the prevention of intimal hyperplasia, which could be investigated through further in vivo studies.
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul.
authors.forename: Yang Jin
authors.initials: YJ
authors.lastname: Park
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul.
authors.forename: Sang-Il
authors.initials: SI
authors.lastname: Min
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul.
authors.forename: In Mok
authors.initials: IM
authors.lastname: Jung
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul.
authors.forename: Taeseung
authors.initials: T
authors.lastname: Lee
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul.
authors.forename: Jongwon
authors.initials: J
authors.lastname: Ha
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul.
authors.forename: Jung Kee
authors.initials: JK
authors.lastname: Chung
authors.affiliation: Department of Surgery, Myongji Hospital, Goyang, Korea.
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul.
authors.forename: Seung-Kee
authors.initials: SK
authors.lastname: Min
keywords: Carotid artery injury; Imatinib; Intimal hyperplasia; Neointimal cell; Sirolimus