benzyloxycarbonylvalyl-alanyl-aspartyl-fluoromethyl-ketone and Heart-Arrest

Understanding the mechanisms of injury associated with cardiac arrest is essential for defining strategies aimed at improving preservation and function of kidneys harvested in non-heart-beating (NHB) donors.. We standardized a model of NHB donors in rats and studied the kinetics and types (apoptosis vs. necrosis) of renal cell death developing during cold storage. Using quantitative polymerase chain reaction, immunoblotting, and caspase inhibition, we also studied the molecular pathways regulating renal cell death in this model.. The kinetics and extent of cell death developing in cortical tubules during cold storage were found to be increased in non-heart-beating (NHB) kidneys. Apoptosis of cortical tubules predominated in NHB kidneys exposed to 10 hr of cold storage, whereas necrosis increased after longer periods of cold ischemia. Shortly after cardiac arrest, a rapid up-regulation of Bax and Hsp 70 was found at the protein level in NHB kidneys. After 24 hr of cold storage, induction of Bax was maintained, whereas protein levels of Hsp70 returned to levels comparable to heart-beating (HB) controls. Also, mRNA levels of Bax were found to increase during cold storage in NHB kidneys. Cortical cell death was found to be largely caspase-independent but responsive to hydroxyl-radical scavenging with dimethyl sulfoxide (DMSO).. Cardiac arrest promotes activation of death-inducing molecules such as Bax and is associated with increased development of caspase-independent renal cell death during cold storage. Developing strategies, such as free radical scavenging, aimed at inhibiting cell death during cold storage, could prove useful for improving preservation of NHB kidneys.

Topics: Amino Acid Chloromethyl Ketones; Animals; bcl-2-Associated X Protein; bcl-X Protein; Caspase Inhibitors; Caspases; Cell Death; Cold Temperature; Cysteine Proteinase Inhibitors; Heart Arrest; HSP70 Heat-Shock Proteins; Ischemia; Kidney Cortex; Kidney Transplantation; Male; Necrosis; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Inbred F344; Tumor Suppressor Protein p53

The aim of this study was to determine whether hypoxic-ischemia from asphyxial cardiac arrest activates brain caspases-1 and -3, and the anti-apoptotic protein, XIAP. Asphyxial cardiac arrest in rats was used to induce hypoxic-ischemia. A pan-caspase inhibitor (zVAD) was given in the treatment group. At 72 h after reperfusion, caspase-3 and XIAP expression were present in multiple vulnerable brain regions, whereas caspase-1 was predominantly found in the CA1 hippocampus. zVAD significantly reduced expression of caspases and XIAP and the number of ischemic neurons in the CA1 hippocampus while neurological deficit scores were improved. We conclude that hypoxic-ischemia increases caspases-1 and-3, and XIAP expression. Treatment with zVAD significantly decreases caspase and XIAP expression in these brain regions and improves neurological outcome.

Topics: Amino Acid Chloromethyl Ketones; Animals; Asphyxia; Brain; Caspase 1; Caspase 3; Caspase Inhibitors; Caspases; Cell Death; Cysteine Proteinase Inhibitors; Down-Regulation; Gene Expression Regulation, Enzymologic; Heart Arrest; Hippocampus; Hypoxia-Ischemia, Brain; Immunohistochemistry; Male; Neurons; Proteins; Rats; Rats, Sprague-Dawley; X-Linked Inhibitor of Apoptosis Protein