Cold preservation-warm reperfusion perturbs cytosolic calcium ion homeostasis in rat liver sinusoidal endothelial cells

Protective effects of phycocyanin on ischemia/reperfusion liver injuries

In this study, phycocyanin (Pc) extracted from Spirulina platensis was used to evaluate its antioxidants effects after ischemia/reperfusion injury (IRI) using the ex-vivo model of isolated perfused rat liver. The rats were divided into eight groups : Control group, where livers were directly perfused after their removal; Cold Ischemia group (CI), livers were treated in the same way as the control group, except that after their collection, they were stored for 12 h and 24 h in the Krebs Henseleit (KH) preservation solution at 4 °C and Treated group (PHY), livers were preserved in the same way as the preceding group except that the KH solution was enriched with phycocyanin at two different concentrations. Pc, a powerful antioxidant, significantly reduced ischemia/reperfusion injury in the liver. In fact, the addition of phycocyanin to the preservation solution significantly decreased the activity of liver transaminases (AST) and (ALT), alkaline phosphatase (ALP), the rate of lipid peroxidation (MDA) and the activity of certain antioxidant enzymes, essentially glutathione-S-transferase (GST) and glutathione peroxidase (GPx). On the other hand, Pc increases the level of thiol groups in hepatic tissues. In conclusion, the results show the Pc-enriched KH conservation solution is effective in preserving the hepatic graft and protecting it against IRI by acting as a potent antioxidant against the products of oxidative stress.

Aggravation of cold-induced injury in Vero-B4 cells by RPMI 1640 medium - identification of the responsible medium components

BACKGROUND

In modern biotechnology, there is a need for pausing cell lines by cold storage to adapt large-scale cell cultures to the variable demand for their products. We compared various cell culture media/solutions for cold storage of Vero-B4 kidney cells, a cell line widely used in biotechnology.

RESULTS

Cold storage in RPMI 1640 medium, a recommended cell culture medium for Vero-B4 cells, surprisingly, strongly enhanced cold-induced cell injury in these cells in comparison to cold storage in Krebs-Henseleit buffer or other cell culture media (DMEM, L-15 and M199). Manufacturer, batch, medium supplements and the most likely components with concentrations outside the range of the other media/solutions (vitamin B12, inositol, biotin, p-aminobenzoic acid) did not cause this aggravation of cold-induced injury in RPMI 1640. However, a modified Krebs-Henseleit buffer with a low calcium concentration (0.42 mM), a high concentration of inorganic phosphate (5.6 mM), and glucose (11.1 mM; i.e. concentrations as in RPMI 1640) evoked a cell injury and loss of metabolic function corresponding to that observed in RPMI 1640. Deferoxamine improved cell survival and preserved metabolic function in modified Krebs-Henseleit buffer as well as in RPMI 1640. Similar Ca2+ and phosphate concentrations did not increase cold-induced cell injury in the kidney cell line LLC-PK1, porcine aortic endothelial cells or rat hepatocytes. However, more extreme conditions (Ca2+ was nominally absent and phosphate concentration raised to 25 mM as in the organ preservation solution University of Wisconsin solution) also increased cold-induced injury in rat hepatocytes and porcine aortic endothelial cells.

CONCLUSION

These data suggest that the combination of low calcium and high phosphate concentrations in the presence of glucose enhances cold-induced, iron-dependent injury drastically in Vero-B4 cells, and that a tendency for this pathomechanism also exists in other cell types.

Complement membrane attack complex and hemodynamic changes during human orthotopic liver transplantation

Hemodynamic changes and elevation of intracellular calcium following reperfusion in human liver transplantation occur rapidly and do not match the time course of cytokine expression, therefore, we postulate involvement of other, pre-formed substances, such as complement. We studied 40 adult patients undergoing liver transplantation. Blood was drawn for estimation of C3, C4, C3 degradation product, membrane attack complex, and CH100 levels and elastase (a marker of neutrophil activation) at induction of anesthesia, 5 minutes before reperfusion, 5 minutes and 60 minutes after reperfusion. Cardiac output was measured by thermodilution and systemic vascular resistance was calculated at these same time points. There was a significant rise in C5b-9 membrane attack complex (P =.0012) with a corresponding fall in C3 (P =.0013) and C4 (P =.0002) levels and a rise in C3 degradation product levels (P =.0006). There was no significant change in CH100. These changes very closely followed the hemodynamic changes of a significant fall in systemic vascular resistance index (P =.0024) and increase in cardiac index (P =.0005). Elastase rose from 356 +/- 53 to 557 +/- 40 microg/L (P <.0001). There is complement activation and neutrophil activation at reperfusion in liver transplantation. Dilution alone cannot explain the fall in C3 and C4 levels as there is a corresponding increase in membrane attack complex and C3 degradation product levels with time. As both C3 and C4 are consumed, the classical pathway must be active, though alternative and lectin activated pathways may also be involved. These findings may, at least in part, explain the hemodynamic changes typically seen at reperfusion in liver transplantation.