Molecular hydrogen: prospective treatment strategy of kidney damage after cardiac surgery.

Abstract

Cardiac surgery-associated acute kidney injury is a frequent postoperative complication driven largely by elevated oxidative stress. Using a porcine model that simulated heart transplantation with 3 hours of extracorporeal circulation (ECC) followed by 60 minutes of spontaneous cardiac reperfusion, researchers assessed whether inhaled 4% H2 gas—administered during anesthesia and throughout ECC blood oxygenation—could protect renal function. Plasma concentrations of creatinine, urea, and phosphorus rose markedly in untreated surgical animals, whereas all three biomarkers returned to near-control levels in the hydrogen-treated group. Western blot analysis of renal tissue revealed activation of the Nrf2/Keap1 signaling pathway and upregulation of superoxide dismutase 1 (SOD1) protein in hydrogen-exposed animals. These findings indicate that H2 inhalation confers renoprotection in the context of cardiac surgery, likely through antioxidant pathway activation.

Mechanism

Inhaled H2 activates the Nrf2/Keap1 antioxidant signaling pathway and upregulates superoxide dismutase 1 (SOD1) protein expression in renal tissue, thereby reducing oxidative stress-mediated kidney damage following cardiac surgery with extracorporeal circulation.