Grapefruit juice increases felodipine oral availability in humans by decreasing intestinal CYP3A protein expression - Lown, K S; Bailey, D G; Fontana, R J; Janardan, S K; Adair, C H; Fortlage, L A; Brown, M B; Guo, W; Watkins, P B (J Clin Invest, 1997)