ACETYLSALICYLIC-ACID, AT HIGH-CONCENTRATIONS, INHIBITS VASCULAR SMOOTH-MUSCLE CELL-PROLIFERATION

The growth of human smooth muscle cells in culture is inhibited by ace tylsalicylic acid (ASA). In comparison to control, the proliferation o f cells treated with 270 mg/L lysinmono(acetytsalicylate)/30 mg/L glyc ine was inhibited by 50-90% under different culture conditions. Cell n umbers per well (control vs. treated) were as follows: (a) 470,500 +/- 55,890 vs. 24,750 +/- 4,030 (p < 0.002) after 6 days in the presence of 10% fetal calf serum (FCS), (b) 160,500 +/- 9,920 vs. 74,000 (p < 0 .001) after 8 days in the presence of 10% human serum; and (c) 387,000 +/- 29,420 vs. 35,250 +/- 1,110 (p < 0.001) after 8 days in the prese nce of 5% FCS. Significant inhibition of growth by lysinmono(acetylsal icylate) at 90 mg/L was noted only for cultures grown with 10% FCS. Lo wer concentrations of this drug were ineffective under all culture con ditions. Higher dosages of ASA, which would prevent not only platelet aggregation but also smooth muscle cell growth, may therefore be indic ated in therapy of patients who undergo percutaneous transluminal coro nary angio (PTCA) or coronary artery transplantation.