Chronic Sildenafil Therapy in the ZSF1 Obese Rat Model of Metabolic Syndrome and Heart Failure With Preserved Ejection Fraction

Autores da FMUP

• Sara Vanessa Amorim Leite

  Autor

• Rui João Gonçalves Cerqueira

  Autor

• Cláudia Cristiana Sousa Mendes

  Autor

• Francisco Aguiar Vasques Novoa Faria

  Autor

• Joaquim Adelino Correia Ferreira Leite Moreira

  Autor

• André Pedro Leite Martins Lourenço

  Autor

Participantes de fora da FMUP

• Moreira Costa, L
• Angelico Goncalves, A
• Fontoura, D

Unidades de investigação

• Cirurgia e Fisiologia

• Laboratório Associado RISE- Rede de Investigação em Saúde

  

  Investigador

  Fernando Carlos De Landér Schmitt

• RISE-Health

  

  Investigador

  Fernando Carlos De Landér Schmitt

Abstract

Although decreased protein kinase G (PKG) activity was proposed as potential therapeutic target in heart failure with preserved ejection fraction (HFpEF), randomized clinical trials (RCTs) with type-5 phosphodiesterase inhibitors (PDE5i) showed neutral results. Whether specific subgroups of HFpEF patients may benefit from PDE5i remains to be defined. Our aim was to test chronic sildenafil therapy in the young male ZSF1 obese rat model of HFpEF with severe hypertension and metabolic syndrome. Sixteen-week-old ZSF1 obese rats were randomly assigned to receive sildenafil 100 mg center dot Kg(-1)center dot d(-1) dissolved in drinking water (ZSF1 Ob SIL, n = 8), or placebo (ZSF1 Ob PL, n = 8). A group of Wistar-Kyoto rats served as control (WKY, n = 8). Four weeks later animals underwent effort tests, glucose metabolism studies, hemodynamic evaluation, and samples were collected for aortic ring preparation, left ventricular (LV) myocardial adenosine triphosphate (ATP) quantification, immunoblotting and histology. ZSF1 Ob PL rats showed systemic hypertension, aortic stiffening, impaired LV relaxation and increased LV stiffness, with preserved ejection fraction and cardiac index. Their endurance capacity was decreased as assessed by maximum workload and peak oxygen consumption (VO2) and respiratory quotient were increased, denoting more reliance on anaerobic metabolism. Additionally, ATP levels were decreased. Chronic sildenafil treatment attenuated hypertension and decreased LV stiffness, modestly enhancing effort tolerance with a concomitant increase in peak, ATP levels and VASP phosphorylation. Chronic sildenafil therapy in this model of HFpEF of the young male with extensive and poorly controlled comorbidities has beneficial cardiovascular effects which support RCTs in HFpEF patient subgroups with similar features.

Keywords

• hypertension; metabolic syndrome; heart failure with preserved ejection fraction; type 5 phosphodiesterase inhibitors