The effect of 5 days of oral nifedipine treatment (~t mg/kg per day in drinking water) on low density lipoprotein (LDL) and cholesterol accumulation in rabbit arteries was determined. Compared with control aortas, nifedipine treatment (w=5) significantly reduced homologous125I-tyramine cellobiose- LDL accumulation (control versus nifedipine: 45.93±4.3 versus 20.14±3.1 ng LDL per milligram dry weight xlO-3,p=0.001) while the reduction of human LDL accumulation (n=5) was not significant (49.1 ±6.1 versus 35.5±4.1 ng LDL per milligram dry weight xlO~3). Aortic accumulation of orally administered ['H] cholesterol was also inhibited by nifedipine (352 ±34 versus 257 ±16 ng cholesterol per milligram dry weight xlO-3,n=10,p=0.022). These findings suggest a possible mechanism for the antiatherosclerotic effect of nifedipine.