Caveolinas y modulación del sistema del óxido nítrico en el hipotiroidismo según avanza la edad.

Abstract

Introduction: Hypothyroidism and age impact on cardiac and renal nitricoxide (NO) production. Caveolins, which are negativemodulators of NO synthase (NOS) activity, are affected byboth factors. Objectives: The aim of this study was to evaluate caveolin (CAV) participationin the modulation of renal and cardiac NOS activityin adult hypothyroid animals. Methods: Euthyroid and hypothyroid [methimazole 0.02% (v/v) in thedrinking water during 28 days] male Sprague-Dawley ratswere used. Animals were sacrificed to remove the heart andkidneys. Results: Right atrial NOS activity decreased with age and hypothyroidism.Caveolin-1 expression increased with age andhypothyroidism. Conversely, left ventricular NOS activityincreased with aging and hypothyroidism and the expressionof both CAV isoforms decreased in adult and hypothyroidgroups. In the renal medulla, hypothyroidism reducedNOS activity in young and raised it in adult animals andCAV-1 expression decreased with age and in hypothyroidyoung animals. Caveolin-3 protein levels decreased in adulthypothyroid animals. Conclusions: Hypothyroidism impacts on NOS activity and on that ofits modulators, caveolins, in the cardiovascular and renalsystems. Hypothyroidism enhances the effects of aging inboth systems.