Association between the degree of platelet-derived growth factor-A chain mRNA expression and coronary arteriosclerosis in the transplanted heart.

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.