Abstract
This review delves into the comparative analysis of avian and mammalian cardiomyocytes, focusing on the role of T–tubule membranes in calcium (Ca2+) concentration management and their significance in fostering resilience to mechanical load. Mammalian cardiomyocytes, equipped with complex T–tubule membranes, facilitate uniform and rapid changes in Ca2+ concentration, essential for maintaining resilience under mechanical stress. In contrast, while lacking T–tubule membranes, avian cardiomyocytes have developed unique mechanisms for rapid Ca2+ adjustments. Although avian and mammalian hearts are similar in macroscopic function and structure, differences at the cellular level, particularly in mechanisms of Ca2+ regulation, provide an insightful perspective on evolutionary adaptation.