Ghrelin Protected Rat Hearts from Damage During Cardiopulmonary Bypass Surgery

Adult male Sprague-Dawley rats were subjected to cardiopulmonary bypass and randomized into four groups of 8: vehicle, ghrelin, ghrelin plus GHSR-1a inhibitor, and ghrelin plus PI3K inhibitor. Researchers measured inflammatory markers (TNF-α, IL-6, myeloperoxidase), oxidative stress, apoptosis, cardiac injury biomarkers, and cardiac function. Complementary in vitro experiments used cultured cardiomyocytes subjected to simulated CPB conditions to confirm findings and test mechanisms.

Millions of patients undergo cardiopulmonary bypass annually for heart surgeries, and the procedure itself causes significant heart damage through inflammation and ischemia-reperfusion injury. There is an unmet clinical need for agents that protect the heart during CPB. This study suggests ghrelin could be such an agent, reducing multiple pathways of injury simultaneously through a well-defined mechanism.

This study adds to the growing body of evidence that ghrelin has cardioprotective properties beyond its known roles in appetite and growth hormone release. Prior work showed ghrelin improves cardiac function in heart failure; this extends those findings to the surgical context of cardiopulmonary bypass. The identification of the GHSR-1a/Akt pathway as the mechanism provides a clear pharmacological target and explains how ghrelin protects the heart at the molecular level.

This was an animal study in rats, and CPB in rats differs from human cardiac surgery in duration, complexity, and scale. The study measured acute effects only — long-term cardioprotection was not assessed. Ghrelin dosing in rats may not translate directly to human dosing. The study used only male rats, limiting generalizability. No comparison was made with existing cardioprotective strategies used during human CPB.