In vivo effects of 13-cis retinoic acid treatment on the concentration of proteins and lipids in serum.

A number of serum components, whose concentrations or gene expression have been shown to be modulated by all-trans retinoic acid in vitro, were monitored in patients before and during treatment with Roaccutane (13-cis retinoic acid, 40-60 mg/day) for severe acne. The 13-cis retinoic acid concentration in serum rose from 5.25 +/- 1.09 to 593 +/- 65 nmol/l (mean +/- SD) 24 h after the latest dose. The concentration of all-trans retinoic acid in serum under Roaccutane treatment was measured in model experiments and shown to be 10-20 nmol/l i.e., 2-4 times the basal levels (4.65 +/- 0.85 nmol/l) when the 13-cis retinoic acid concentration was 370-980 nmol/l. The concentrations of creatine kinase-MB, apolipoprotein B, total cholesterol and LDL cholesterol increased significantly while the other measured serum components, including lipoprotein lipase activity, were unaffected by Roaccutane treatment.