Hyperbaric oxygen mitigates KIM-1 and inflammatory cytokine levels in kidney transplantation

Abstract

The aim of this study was to investigate the effect of hyperbaric oxygen (HBO2) administration applied during cold ischemic time to organs removed from donors before kidney transplantation. A total of 24 rats were divided into three groups: Group 1 was the control group, Group 2 received 60 minutes of HBO2 at 2.5 atmospheres absolute, and Group 3 received 120 minutes of 2.5 ATA HBO2. The renal artery was entered with a polyethylene catheter and perfused with a standard organ preservation solution. Falcon tubes containing organs obtained from rats in Groups 2 and 3 were placed in a box supported by ice blocks. The temperature was kept constant at 4 °C and the box was placed in a pressure tank with 2.5 ATA HBO2. HBO2 was applied for 60 and 120 minutes, respectively. Organ samples were harvested at the end of 24 hours for histopathological evaluation, immunohistochemical analysis of TNF-α and IL-18, TUNEL analysis for apoptosis, and gene expression levels of kidney injury molecule-1 (KIM-1) and caspase-3. In histopathological examinations, hematoxylin and eosin staining was performed and samples were evaluated for tubular necrosis and vacuolization criteria. Group 2 and Group 3 had significant decreases compared to Group 1 in this regard. Immunohistochemical staining was performed for TNF-α, IL-18, and apoptosis levels; significant decreases were found in Groups 2 and 3. There were significant decreases in Groups 2 and 3 for KIM-1 and caspase-3 gene expression levels compared to Group 1, as well. Thus, it was demonstrated that during the cold ischemic period before kidney transplantation, HBO2 administration to organs removed from donors can reduce apoptotic cell numbers, inflammatory cytokine release, and histopathological damage to the organs as well as decreasing the expression of the KIM-1 gene, which is an indicator of kidney damage.