Vascular resistance function in myocardial infarction rats.

Author(s)

Gisele Kruger Couto

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2012-04-02

Examining board members

Luciana Venturini Rossoni; Zuleica Bruno Fortes; Virgínia Soares Lemos; Edilamar Menezes de Oliveira; Ivanita Stefanon

• Advisor: Luciana Venturini Rossoni

Abstract

This study assessed the reactivity in skeletal muscle resistance arteries (SMRA) and in septal coronary arteries (SC) from rats with slight (sliLVD) and severe (sevLVD) left ventricular dysfunction after myocardial infarction (MI). SMRA and the SC were mounted on a wire myograph. The endothelium-dependent relaxation by acetylcholine (ACh) was reduced in SMRA from sevLVD; but it was preserved in sliLVD. The ACh-relaxation was reduced in SC from sevLVD; while it was increased in sliLVD. The nitric oxide (NO) donor relaxation was unchanged in all arteries. Using DAF-2 probe in SC, before and after ACh stimulation, it was observed NO production decreased in SC from sevLVD, while it was increased in sliLVD. Reactive oxygen species was increased in SC from sevLVD and it was reduced in sliLVD. Neuronal and endothelial NO synthase and superoxide dismutase isoforms protein expression were greater in SC from sliLVD as compared to SHAM. In conclusion, SMRA and SC function is differentially modulated on the dependency of the cardiac function after MI. (AU)