Estudo sobre a ativação dos receptores canabinoides na função cardíaca de matrinxã, Brycon amazonicus: expressão de proteínas envolvidas no manejo do cálcio

Abstract

This study aimed to evaluate the effects of activation of CB1 and CB2 receptors on proteins involved in myocardial calcium handling of the tropical fish matrinxã, Brycon amazonicus. Three experimental groups were employed: control, treated with the vehicle (DMSO 2.5% in saline with a drop of Tween-20) and WIN and HU groups, both treated with a single dose (1 mg.kg-1) of cannabinoids synthetic WIN 55 212-2 (non-specific) and HU 308 (specific for CB2), respectively, dissolved in vehicle. After 24 hours, the ventricles (n = 10) were collected from each experimental group and, after total proteins extraction, analysis of Sarcoplasmic Reticulum Ca2+-ATPase (SERCA), sodium/calcium exchanger (NCX) and phospholamban (PLB) expressions were carried out using the molecular biology technique Western Blotting. Increases were detected (p<0.05) in the expression of PLB and NCX in WIN and HU groups and there was a significant increase in SERCA expression only in the HU group. Therefore, activation of cannabinoid receptors CB1 and CB2 can play an important role in cardiac function, positively regulating the levels of calcium handling proteins.