The critical injury to liver during cold preservation is believed to occur to the sinusoidal endothelium. In this study the viability of cultured sinusoidal endothelial cells from rat liver was assessed during storage in University of Wisconsin solution at 4 degrees C. The vast majority of cells (83 +/- 12%) died within 24 hr of storage. Addition of KCN (1 mM) to the solution to simulate hypoxia markedly increased survival: only 3 +/- 2% of cells had lost viability after 24 hr in the presence of cyanide. Further experiments showed that other inhibitors of mitochondrial ATP formation (antimycin A 1 microM, rotenone 1 microM, oligomycin 10 microM, carbonyl cyanide m-chlorophenylhydrazone 1 microM) were protective as well, whereas glucose (10 mM) greatly diminished the protective effect of cyanide (loss of viability 38 +/- 7% after 24 hr). ATP measurements confirmed the correlation between the energy state of the cells and cell death: ATP levels after 6 hr of incubation were 19.9 +/- 4.0 nmol/10(6) cells in UW solution, 13.7 +/- 2.9 nmol/10(6) cells in UW + glucose, 6.9 +/- 1.9 nmol/10(6) cells in UW + KCN + glucose and 1.9 +/- 1.5 nmol/10(6) cells in UW + KCN. In contrast to the protective effect observed in UW solution, addition of KCN to Krebs-Henseleit buffer led to increased endothelial cell damage upon cold storage. We therefore conclude that in UW solution damage to the sinusoidal endothelium is energy-dependent.