Submit Manuscript  

Article Details


Diazoxide Modulates Cardiac Hypertrophy by Targeting H2O2 Generation and Mitochondrial Superoxide Dismutase Activity

Author(s):

Aline Maria Brito Lucas, Joana Varlla de Lacerda Alexandre, Maria Thalyne Silva Araújo, Cicera Edna Barbosa David, Yuana Ivia Pontes Viana, Beatriz Neves Coelho, Francisco Rodrigo Lemos Caldas, Anna Lídia Nunes Varela, Alicia Juliana Kowaltowski and Heberty Tarso Facundo*   Pages 1 - 8 ( 8 )

Abstract:


Background: Cardiac hypertrophy involves marked wall thickening or chamber enlargement. If sustained, this condition will lead to dysfunctional mitochondria and oxidative stress. Mitochondria have ATP-sensitive K+ channels (mitoKATP) in the inner membrane that modulate the redox status of the cell.

Objective: We investigated the in vivo effects of mitoKATP opening on oxidative stress in isoproterenol-induced cardiac hypertrophy.

Method: Cardiac hypertrophy was induced in Swiss mice treated intraperitoneally with isoproterenol (ISO - 30 mg/kg/day) for 8 days. From day 4, diazoxide (DZX - 5 mg/kg/day) was used in order to open mitoKATP (a clinically relevant therapy scheme) and 5-hydroxydecanoate (5HD - 5 mg/kg/day) or glibenclamide (GLI - 3 mg/kg/day) were used as mitoKATP blockers.

Results: Isoproterenol-treated mice had elevated heart weight/tibia length ratios (HW/TL). Additionally, hypertrophic hearts had elevated levels of carbonylated proteins and Thiobarbituric Acid Reactive Substances (TBARS), markers of protein and lipid oxidation. In contrast, mitoKATP opening with DZX avoided ISO effects on gross hypertrophic markers (HW/TL), carbonylated proteins and TBARS, in a manner reversed by 5HD and GLI. Moreover, DZX improved mitochondrial superoxide dismutase activity. This effect was also blocked by 5HD and GLI. Additionally, ex vivo treatment of isoproterenol-induced hypertrophic cardiac tissue with DZX decreased H2O2 production in a manner sensitive to 5HD, indicating that this drug also acutely avoids oxidative stress.

Conclusion: Our results suggest that diazoxide blocks oxidative stress and reverses cardiac hypertrophy. This pharmacological intervention could be a potential therapeutic strategy to prevent oxidative stress associated with cardiac hypertrophy.

Keywords:

Mitochondria, Hypertrophy, Oxidative Stress, Free Radicals, Antioxidants, Hydrogen Peroxide

Affiliation:

Faculdade de Medicina, Universidade Federal do Cariri, Barbalha, CE, Faculdade de Medicina, Universidade Federal do Cariri, Barbalha, CE, Faculdade de Medicina, Universidade Federal do Cariri, Barbalha, CE, Faculdade de Medicina, Universidade Federal do Cariri, Barbalha, CE, Faculdade de Medicina, Universidade Federal do Cariri, Barbalha, CE, Faculdade de Medicina, Universidade Federal do Cariri, Barbalha, CE, Instituto Federal de Educação, Ciência e Tecnologia do Ceará, Juazeiro do Norte, Faculdade de Medicina, Universidade Federal do Cariri, Barbalha, CE, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Faculdade de Medicina, Universidade Federal do Cariri, Barbalha, CE



Read Full-Text article