Hypoxia inducible factor-1α accumulation in steatotic liver preservation: Role of nitric oxide

Figure 1 Hypoxia-inducible factor-1α protein levels in liver after 24 h of cold storage. A: Representative Western (top) and densitometric analysis (bottom); B: Hypoxia-induced factor-1α (HIF-1α) protein levels quantified by Trans AM HIF-1α kit; Alanine transaminase (ALT) (C) and aspartate transaminase (AST) (D) levels in flushing effluent after 24 h of cold storage. University Wisconsin (UW): Liver preserved in UW solution; IGL-1: Liver preserved in IGL-1 solution; IGL-1 + trimetazidine (TMZ) (trimetazidine): Liver preserved in IGL-1 solution with TMZ; Cont 1: Liver flushed without cold preservation. ^aP < 0.05 vs Cont 1; ^cP < 0.05 vs UW; ^eP < 0.05 vs IGL-1.

Figure 2 Hypoxia-inducible factor-1α, nitrite/nitrate and endothelial nitric oxide synthase. A: Hypoxia-induced factor-1α (HIF-1α) protein levels quantified by Trans AM HIF-1α kit after 24 h of cold storage and 120 min of normothermic reperfusion; B: Representative Western blotting of HIF-1α (top) and densitometric analysis (bottom) after 24 h of cold storage and 120 min of normothermic reperfusion; C: Nitrite/nitrate levels after 120 min of normothermic reperfusion; D: Endothelial nitric oxide synthase (eNOS) protein levels in liver after 120 min of normothermic reperfusion. Representative Western blotting (top) and densitometric analysis (bottom). Cont 2: Liver flushed and perfused ex vivo without cold preservation; University Wisconsin (UW): Liver preserved in UW solution; IGL-1 + trimetazidine (TMZ) + NAME: Liver preserved in IGL-1 solution with TMZ and an nitric oxide synthesis inhibitor, L-NAME. ^aP < 0.05 vs Cont 2; ^cP < 0.05 vs UW; ^eP < 0.05 vs IGL-1; ^gP < 0.05 vs IGL-1 + TMZ.

Figure 3 Endothelial nitric oxide synthase immunohistochemistry in steatotic and non-steatotic livers. Control livers and livers stored in University Wisconsin (UW) solution show only a little positivity for endothelial nitric oxide synthase (eNOS), localized typically in a few sinusoidal endothelial cells (arrows). The positivity increases when the livers are submitted to cold storage with IGL-1 solution and even more when trimetazidine (TMZ) is added to IGL-1 solution. When TMZ is added to IGL solution, some positive Kupffer cells (arrowhead) can be observed also. The addition of L-NAME to IGL-1 + TMZ solution reduced eNOS activity.

Figure 4 Alanine transaminase (A), Aspartate transaminase (B) levels in perfusate, bile flow (C), percentage of sulfobromophthalein in bile (D), and vascular resistance (E) of steatotic and non-steatotic livers after 120 min of normothermic reperfusion. ^aP < 0.05 vs Cont 2; ^cP < 0.05 vs University Wisconsin (UW); ^eP < 0.05 vs IGL-1; ^gP < 0.05 vs IGL-1 + trimetazidine (TMZ). BSP: Sulfobromophthalein; ALT: Alanine transaminase; AST: Aspartate transaminase.

Figure 5 Glutamate dehydrogenase and heme oxygenase-1. A: Glutamate dehydrogenase (GLDH) levels after 120 min of reperfusion; B: Heme oxygenase-1 (HO-1) protein levels in liver after 120 min of normothermic reperfusion. Representative Western blotting at (top) and densitometric analysis at (bottom). ^aP < 0.05 vs Cont 2; ^cP < 0.05 vs University Wisconsin (UW); ^eP < 0.05 vs IGL-1; ^gP < 0.05 vs IGL-1 + trimetazidine (TMZ).