Nifedipine increases and glyceryl trinitrate decreases apparent liver blood flow in normal subjects

The effects of sublingual nifedipine (10 mg) and of glyceryl trinitrate (500 micrograms), which produce arterial and venous vasodilatation respectively, on indocyanine green estimated apparent liver blood flow (LBF) were studied in six healthy volunteers. Nifedipine significantly increased (33 +/- 12%; mean +/- s.e. mean) and glyceryl trinitrate significantly reduced (18 +/- 3%) LBF. There was a positive relationship (r = 0.92, P less than 0.05) between the reduction in mean arterial pressure produced by nifedipine and the percentage increase in LBF. These results show that single doses of nifedipine and glyceryl trinitrate significantly alter LBF.