A coronary porcine organ culture system for studies of postangioplasty cell proliferation.
BACKGROUND
Restenosis after angioplasty is generally considered to be caused mainly by an increased proliferation of smooth muscle cells, but recently this theory has been questioned.


METHODS
Fresh hearts of 25 pigs were obtained and the left anterior descending coronary arteries carefully prepared, cut into segments and treated with a 3 mm standard balloon catheter for 60 s with 3, 6, 9 and 12 bar. Immediately after angioplasty the specimens were cultured in a mixture of WM/F-12, supplemented with 15% fetal calf serum.


RESULTS
After staining with a modified Verhoeff-van Gieson technique, intimal wall thickening was analysed with a computerized morphometric system. After 14 days in culture, angioplasty with 6, 9 and 12 bar resulted in a significant (P < 0.05) increase of neointimal thickening. After 21 days, a significant increase of neointimal thickening was seen after ballooning with 3, 9 or 12 bar (P < 0.05). After 28 days angioplasty with 3 or 6 bar showed a dose-dependent increase of neointima, which was not further increased after ballooning with 9 or 12 bar. Significance was reached after ballooning with 6, 9 and 12 bar (P < 0.05). Smooth muscle cells were identified with a monoclonal antibody against smooth muscle alpha-actin. Endothelial cells were identified using an anti-human von Willebrand factor. To determine the number of cells undergoing DNA synthesis, bromodeoxyuridine, a thymidine analogue, was added to the culture media 18 h before fixation. It was detected with a monoclonal antibody, with a biotinylated horse-anti-mouse antibody as secondary antibody. After 4 and 7 days in culture bromodeoxyuridine-positive cells were observed, indicating an early proliferative response after angioplasty.


CONCLUSIONS
The coronary organ culture model offers opportunities for investigations of complex cellular events that are considered important in the development of restenosis. The data reported emphasize the importance of an early proliferative response of smooth muscle cells after coronary angioplasty, resulting in a significant neointimal thickening.
Voisard
R
R
Department of Cardiology, University of Ulm, Germany.
Jensch
V
V
Baur
R
R
Höher
M
M
Hombach
V
V
D000800:Angioplasty, Balloon; D000818:Animals; D002455:Cell Division; D003327:Coronary Disease / Q000473:pathology* / Q000628:therapy; D004730:Endothelium, Vascular / Q000473:pathology*; D007150:Immunohistochemistry; D009131:Muscle, Smooth, Vascular / Q000473:pathology*; D009924:Organ Culture Techniques; D013552:Swine; D013997:Time Factors