Background: Low-potassium (LP) solution with Dextran (Dx) improves lung preservation. Nevertheless, the role of Dx in simple cold storage is not established yet. This study was designed to investigate the relationship between molecular weight and concentration of Dx in LP solutions and its effects on cell viability after prolonged hypothermic preservation.
Methods: Human fetal lung fibroblasts (WI-38) were preserved at 10 degrees C for 16 hrs in five solutions containing respectively Dx11, Dx17, Dx39.2, Dx71, Dx178 at 2% and at 5% concentrations and in LP solution without Dx. Cell viability was assessed by means of both the analysis of the total protein content (cytotoxicity index) and the rate of protein synthesis (index of cellular functioning).
Results: No differences were recorded in total protein content among the solutions tested. By contrast, the index of cellular functioning was significantly higher using LPDx178 at both concentrations. However, LPDx178 exerted a more significant cytotoxic effect than did LP alone.
Conclusions: These effects were not mediated by the variation of osmolarity; two factors probably influenced this protection: the low oncotic pressure of the LPDx178 solution and an effect chemically specific due to the increased molecular weight of Dx still unknown. Nevertheless, during 10 degrees C preservation, WI-38 cells were better preserved with LP solution without Dx confirming, thus, that during simple cold storage the presence of an oncotic pressure might be harmful.