Although intimal and medial proliferation of smooth muscle cells is recognized as one of the key mechanisms in the development of graft
coronary arteriosclerosis, the role of
platelet-derived growth factor (PDGF) in this process is still uncertain, because of the undetermined pathogenesis of graft
coronary arteriosclerosis (GCA). In the present study, the correlation between the extent of GCA and the degree of
PDGF-A chain expression in cardiac grafts was investigated in 21 rats with GCA of varying extent. Lewis rats underwent heterotopic
heart transplantation from Wistar King donors and were treated with
cyclosporine A (10 mg/kg/day) (n = 7),
15-deoxyspergualin (5 mg/kg/day) (n = 7), or
Multiglycosidorum tripterygii (MT) (30 mg/kg/day) (n = 7). Histological evaluations of
coronary arteriosclerosis, as well as Northern blot analysis of graft
PDGF-A chain expression were made, 60 days after
transplantation. Graft
coronary arteriosclerosis of varying extent was observed among the 21 transplanted hearts. Significant correlations were found between the
PDGF-A chain
mRNA expression of cardiac allograft and the grade of arterial intimal thickening (Spearman's r = 0.76, P < 0.005) as well as the incidence of diseased vessels (r = 0.82, P < 0.001). The
PDGF-A chain
mRNA expression of the cardiac allograft is associated with the extent of GCA, indicating that
PDGF-A plays an important role in the development of GCA.