VASCULAR AQUAPORIN 1 CHANGES AFTER OSMOTIC STRESS AND POSTERIOR REHYDRATION DURING POSTNATAL STAGES

V. NETTI, M. VATRELLA, A. IOVANE M., CHAMORRO, ROSÓN, MI, A. FELLET, A.M. BALASZCZUK

Londres

Congreso; 22nd European Meeting on Hypertension and Cardiovascular Protection; 2012

European Society of Hypertesnsion

Aquaporin 1 (AQP1) plays a major role in membrane water transport processes in many tissues in order to maintain cellular osmotic environment and body fluid balance. However, little is known about AQP1 in vascular tissue, which is a target organ for the physiological alterations induced by osmotic stress, particularly during postnatal life. Objective: the aim of the present study was to evaluate vascular AQP1 protein levels and localization in rats subjected to hypovolemic state following water restriction. Method: male Sprague-Dowley 25 and 50 days old rats were divided in the following groups: R: water restriction during 3 days; C: water ad libitum for 3 days; Rs: water restriction during 3 days + oral rehydration salts (according to WHO) for 3 days. At the end of each experiment, we determined: hematocrit, body weight, systolic blood pressure (SBP) and heart rate (HR); animals were then sacrificed to evaluate in thoracic aorta AQP1 protein levels (Western Blot) and localization (Immunohistochemistry). Results: AQP1 immunohistochemical staining of the thoracic aorta revealed its presence in the vascular endothelium and smooth muscle, this patterm being similar amog the studied groups of animals. Western Blot analysis showed that in C groups, AQP1 protein levels were lower in 50 days old animals compared to 25 days old pups. In the youngest group, there were no changes in AQP1 expression with water restriction and posterior rehydration, whereas in 50 days old rats, glycosylated and non-glycosylated AQP1 were only increased after rehydration with oral salts solution (p