Evaluation of the interaction of endothelial nitric oxide synthase (eNOS)/Caveolin-1 in the nitric oxide bioavailability in aortas of spontaneously hypertensive rats (SHR) at the end of pregnancy

Abstract

Previous studies have shown that pregnancy is a favorable physiological condition to reduce blood pressure and vascular reactivity to phenylephrine (PE) and reestablishment of endothelial function in spontaneously hypertensive rats (SHR). Mechanisms that increase NO bioavailability in SHR vessels at the end of pregnancy have been investigated and suggest that endothelial nitric oxide synthase (eNOS) activity is increased. Possible changes in the protein-protein interactions of eNOS activity control are being investigated. Our hypothesis is that the eNOS/Cav-1 interaction is increased in aortas of pregnant normotensive and hypertensive rats. The objective of this study will be to analyze whether pregnancy changes the eNOS/Caveolina-1 (Cav-1) interaction in aortas of normotensive and hypertensive rats. Protein expression of Cav-1 by Western Blot and eNOS/Cav-1 interaction by co-immunoprecipitation method will be evaluated in aortic homogenates of non-pregnant (NP) and pregnant (P), Wistar and SHR rats. In functional studies, we will evaluate the participation of the caveolae in the hyporeactivity to PE observed in aortas of pregnant rats. Thus, concentration-response curves to PE will be performed in aortas rings with endothelium in the presence or absence of 10 mmol/L of cyclo-beta-methyl-dextrin, a drug that alters the stability of the caveolae. The results will be analyzed (Student's t test or ANOVA) and the difference will be considered significant when p <0.05.