Nitric oxide protects rat hepatocytes against reperfusion injury mediated by the mitochondrial permeability transition

• DOI: 10.1002/hep.20197
• Publication Date: 2004-05-27T20:01:37Z
• Authors: Jae-Sung Kim; Shigetoshi Ohshima; Peter Pediaditakis; John J. Lemasters
• Keywords: 0301 basic medicine; Mitochondria, Liver; S-Nitroso-N-Acetylpenicillamine; Nitric Oxide; Permeability; Rats; 03 medical and health sciences; Adenosine Triphosphate; Guanylate Cyclase; Reperfusion Injury; Hepatocytes; Animals; Nitric Oxide Donors; Cyclic GMP; Cells, Cultured

We investigated the effects of nitric oxide (NO) on hepatocellular killing after simulated ischemia/reperfusion and characterized signaling factors triggering cytoprotection by NO. Cultured rat hepatocytes were incubated in anoxic Krebs-Ringer-HEPES buffer at pH 6.2 for 4 hours reoxygenated 7.4 2 hours. During reoxygenation, some exposed to combinations NO donors (S-nitroso-N-acetylpenicillamine [SNAP] others), a cGMP analogue (8-bromoguanosine-3,5-cGMP [8-Br-cGMP]), cGMP-dependent protein kinase inhibitor (KT5823). Cell viability was determined way propidium iodide fluorometry. Inner membrane permeabilization mitochondrial depolarization monitored confocal microscopy. SNAP, but not oxidized increased during reperfusion decreased cell killing. Other 8-Br-cGMP also prevented Both guanylyl cyclase inhibition blocked However, 5-hydroxydecanoate diazoxide- K(ATP) channel modulators-did affect NO-dependent or injury. microscopy showed repolarization, followed depolarization, inner permeabilization, death. In presence either SNAP 8-Br-cGMP, repolarization sustained preventing isolated liver mitochondria, cytosolic extract adenosine triphosphate Ca(2+)-induced permeability transition (MPT), an effect that reversed KT5823. conclusion, prevents MPT-dependent necrotic ischemic through pathway, events may represent target preconditioning.