Effects of physiologic albumin and hespan levels on hepatocytes in vitro

Background: Although albumin and hydroxyethyl starch (HES) are routinely us ed in critically ill, hypoalbuminemic patients, no studies have tested the effect of supplemental albumin and HES on hepatocyte Function. Methods: In this study, the effects of these agents were evaluated by using stable, rat hepatocyte cultures in a collagen sandwich configuration. Hepa tocyte synthesis of albumin, urea, and intracellular triglycerides was moni tored in Dulbecco's modified Eagle medium (supplemented with fetal bovine s erum, hydrocortisone, L-proline, gentamycin, and insulin) without supplemen tal colloid (control cultures) and with supplemental 2% bovine serum albumi n (BSA), 4% BSA, 2% HES, or 4% HES, Results: The albumin secretion in control cultures rose from 31.03 mu g/day per 10(6) cells on day 3 to 154.17 mu g/day per 10(6) cells by day 12 and remained constant, In contrast, the level of albumin synthesis in the 2% an d 4% BSA groups rose from significantly higher initial values (p < 0.05) of 71.25 mu g/day per 106 cells and 73.27 mu g/day per 10(6) cells, respectiv ely, to 127.61 mu g/day per 10(6) cells and 107.95 mu g/day per 10(6) cells by day 7, then declined rapidly to 58.98 mu g/day per 10(6) cells and 41.2 8 mu g/day per 106 cells by day 12 when cell disruption was present. HES al so reduced albumin synthesis. The urea genesis in the control groups and in the treatment groups was found to be comparable throughout the study, The BSA supplemented groups accumulated large amounts of intracellular lipid dr oplets during the experiment, The intracellular triglycerides analysis foun d the 4% BSA group to be significantly (p < 0.05) higher than the 4% HES, Conclusion: BSA, added to a collagen sandwich hepatocyte preparation, cause s reduced hepatocyte synthesis by day 8, probably a result of intracellular triglyceride accumulation, whereas HES reduces synthesis through unidentif ied mechanisms.