During neuronal activity, Müller cells are surrounded by a hypotonic environment, leading to cell swelling and consequently to a regulatory volume decrease (RVD) response. We previously demonstrated in human Müller cells (MIO-M1) that RVD depends on the e

MARIA TERESA POLITI; FEDERICO OCHOA; VANINA NETTI; RAUL FERREYRA; GUILLERMO BORTMAN; CELINA MORALES; ANTONIO PIAZZA; CAPURRO CLAUDIA

Congreso; SAFIS-SAIC 2018; 2018

Background: Cardiopulmonary bypass (CPB) is an essential strategy in heart valve replacement surgery; however, it may produce myocardial edema and dysfunction. Aquaporins (AQP) 1 and 4 are selective water channels found in myocardial tissue. In animals, AQP1 increases after CPB and possibly produces myocardial edema. In human subjects information is still scarce. We designed an observational study to evaluate changes in AQP1 and 4 expression after CPB using myocardial biopsies from adult patients undergoing aortic valve replacement surgery. Our previous results suggest that AQP1 expression increases after CPB, while AQP4 expression decreases. The goals of this study are: 1) To identify the cellular localization of AQP1 and 4; 2) To explore possible candidates that may explain changes in AQPs expression during CPB. Methods: 15 patients undergoing aortic valve replacement surgery were enrolled. Biopsies were taken from the anterior wall of the left ventricle before and after CPB using an automatic transmural fine-needle. Immunohistochemistry was performed using anti-AQP1 and anti-AQP4 antibodies. Data from routine blood tests were collected. Data are expressed as mean ± SEM. Results: Immunohistochemistry staining identified AQP1 expression in the endothelium of myocardial capillaries and AQP4 expression in cardiomyocytes, both before and after CPB. Throughout CPB, there was an increase in calculated plasmatic osmolarity (in mOsm: 287.5±2.8 vs 292.0±1.7; p=0.0346) and glycemia (in mg/dl: 118.9±7.5 vs 194.6±10.5; p