Hydrogen Gas Protects Kidneys During Heart Surgery in Pigs

Authors
Journal
Canadian Journal of Physiology and Pharmacology
Year
DOI
10.1139/cjpp-2023-0098
Study Type
Pig
Outcome
Positive
Peer Reviewed
Yes
Country
Slovakia
Health Condition
Cardiac Surgery-Associated Acute Kidney Injury
Body System
Renal

TL;DR

Inhaling hydrogen gas during and after pig heart surgery reduced signs of kidney injury.

Key Finding

Pigs that inhaled 4% hydrogen gas during cardiac surgery showed normalized kidney function markers and activation of antioxidant defense pathways, compared to pigs that did not receive hydrogen treatment.

Summary

Researchers tested whether inhaling molecular hydrogen gas could protect the kidneys of pigs undergoing heart surgery. During surgery, the pigs' kidneys showed signs of damage (elevated waste products in the blood). Pigs that received hydrogen gas during surgery showed improvement in these markers, and their kidney tissue showed activation of protective antioxidant systems (mechanisms that fight cellular damage from oxidative stress).

Practical Takeaway

This is an early-stage animal study suggesting hydrogen gas may help protect kidneys during heart surgery by reducing oxidative stress. However, this was only tested in pigs, not humans, so it's unclear whether these results would apply to people. Much more research, including human trials, would be needed before hydrogen could be considered a treatment for surgery-related kidney injury.

Abstract

Cardiac surgery-associated acute kidney injury (CS-AKI) is a common postoperative complication, mostly due increasing oxidative stress. Recently, molecular hydrogen (H2 gas), has also been applied to cardiac surgery due to its ability to reduce oxidative stress. We evaluated the potential effect of H2 application on the kidney in an in vivo model of simulated heart transplantation. Pigs underwent cardiac surgery with 3 hours while connected to extracorporeal circulation (ECC) and subsequent 60 minutes of spontaneous reperfusion of the heart. We used two experimental groups: T - pigs after transplantation, TH - pigs after transplantation treated with 4% H2 mixed with air during inhalation of anesthesia and throughout oxygenation of blood in ECC. The levels of creatinine, urea and phosphorus were measured in plasma. Renal tissue samples were analyzed by Western blot method for protein levels of Nrf2, Keap-1, and SOD1. After cardiac surgery, selected plasma biomarkers were elevated. However, H2 therapy was followed by the normalization of all these parameters. Our results suggest activation of Nrf2/Keap1 pathway as well as increased SOD1 protein expression in the group treated with H2. The administration of H2 had a protective effect on the kidneys of pigs after cardiac surgery, especially in terms of normalization of plasma biomarkers to control levels.