Reversible pulmonary trunk banding: IX. G6PD activity of adult goat myocardium submitted to ventricular retraining

• Published in: Revista brasileira de cirurgia cardiovascular Vol. 28; no. 4; p. 482
• Main Authors: Assad, Renato Samy, Miana, Leonardo Augusto, Fonseca-Alaniz, Miriam Helena, Abduch, Maria Cristina Donadio, Silva, Gustavo José Justo da, Oliveira, Fernanda Santos de, Moreira, Luiz Felipe Pinho, Krieger, José Eduardo
• Format: Journal Article
• Language: English
• Published: Brazil Sociedade Brasileira de Cirurgia Cardiovascular 2013
• Subjects: Animals; Biomarkers - metabolism; Blood Pressure; Cardiology; Disease Models, Animal; Energy Metabolism; Glucosephosphate Dehydrogenase - metabolism; Goats; Heart surgery; Heart Ventricles - enzymology; Heart Ventricles - physiopathology; Hemodynamics; Hypertrophy, Right Ventricular - enzymology; Hypertrophy, Right Ventricular - physiopathology; Myocardium - enzymology; Pulmonary Artery - surgery; Time Factors; Transposition of Great Vessels - surgery; Ventricular Dysfunction, Right - enzymology; Ventricular Dysfunction, Right - physiopathology
• ISSN: 0102-7638; 1678-9741
• DOI: 10.5935/1678-9741.20130079

Increased glucose 6-phosphate dehydrogenase activity has been demonstrated in heart failure. This study sought to assess myocardial glucose 6-phosphate dehydrogenase activity in retraining of the subpulmonary ventricle of adult goats. Eighteen adult goats were divided into three groups: traditional (fixed banding), sham, and intermittent (adjustable banding, daily 12-hour systolic overload). Systolic overload (70% of systemic pressure) was maintained during a 4-week period. Right ventricle, pulmonary artery and aortic pressures were measured throughout the study. All animals were submitted to echocardiographic and hemodynamic evaluations throughout the protocol. After the study period, the animals were killed for morphological and glucose 6-phosphate dehydrogenase activity assessment. A 55.7% and 36.7% increase occurred in the intermittent and traditional right ventricle masses, respectively, when compared with the sham group (P<0.05), despite less exposure of intermittent group to systolic overload. No significant changes were observed in myocardial water content in the 3 groups (P=0.27). A 37.2% increase was found in right ventricle wall thickness of intermittent group, compared to sham and traditional groups (P<0.05). Right ventricle glucose 6-phosphate dehydrogenase activity was elevated in the traditional group, when compared to sham and intermittent groups (P=0.05). Both study groups have developed similar right ventricle hypertrophy, regardless less systolic overload exposure of intermittent group. Traditional systolic overload for adult subpulmonary ventricle retraining causes upregulation of myocardial glucose 6-phosphate dehydrogenase activity. It may suggest that the undesirable "pathologic systolic overload" is influenced by activation of penthose pathway and cytosolic Nicotinamide adenine dinucleotide phosphate availability. This altered energy substrate metabolism can elevate levels of free radicals by Nicotinamide adenine dinucleotide phosphate oxidase, an important mechanism in the pathophysiology of heart failure.