Fig. 4. Time-dependent secretion of albumin in cultured rat small hepatocytes. Cells were cultured for 9 weeks and the culture medium was collected at day 1 and weeks 1, 3, 4, 5, 6, 7 and 9 of the culture period. Each value represents the albumin secretion into the culture medium in µg albumin per ml and 24 hours normalized to the 18S rRNA, which was quantitatively measured by real-time PCR. Each time point represents the mean±SD of five determinations. One of two independent experiments is given.