Effects of nitric oxide system and osmotic stress on Aquaporin-1 in the postnatal heart.

NETTI, VANINA; ZOTTA, ELSA; VATRELLA, MARIANA; BALASZCZUK ANA M.; IOVANE, AGUSTINA; FELLET, ANDREA

BIOMEDICINE & PHARMACOTHERAPY = BIOMEDECINE & PHARMACOTHERAPIE.

ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER

Lugar: Paris; Año: 2016 vol. 81 p. 225 - 234

0753-3322

Aquaporin-1 (AQP1) is expressedin the heart and its relationshipwith NO system has not been fullyexplored. The aims of this workwere to study the effects of NOsystem inhibition on AQP1 abundanceand localization and evaluate AQP1S-nitrosylation in a model of waterrestriction during postnatal growth.Rats aged 25 and 50 days (n=15)were divided in: R: water restriction;C: water ad libitum; RL: L-NAME(4mg/kg.day) + water restriction;CL: L-NAME + water ad libitum.AQP1 protein levels, immunohistochemistryand S-nitrosylation (colocalizationof AQP1 and S-nitrosylated cysteinesby confocal microscopy) were determinedin cardiac tissue. We also evaluatedthe effects of NO donor sodiumnitroprusside (SNP) on osmoticwater permeability of cardiac membranevesicles by stopped-flow spectrometry.AQP1 was present in cardiac vascularendothelium and endocardium inC and CL animals of both ages.Cardiac AQP1 levels were increasedin R50 and RL50 and appeared incardiomyocyte plasma membrane.No changes in AQP1 abundance orlocalization were observed in R25,but RL25 group showed AQP1 presenceon cardiomyocyte sarcolemma. AQP1S-nitrosylation was increased inR25 group, without changes in the50-day-old group. Cardiac membranevesicles expressing AQP1 presenteda high water permeability coefficientand pretreatment with SNP decreasedwater transport. Age-related influenceof NO system on AQP1 abundanceand localization in the heart mayaffect cardiac water homeostasisduring hypovolemic state. IncreasedAQP1 S-nitrosylation in the youngestgroup may decrease osmotic waterpermeability of cardiac membranes,having a negative impact on cardiacwater balance.Keywords