Data/hora: 02/06/2024 06:28:05

Provedor de dados: 	56	
País: 	Brazil	
Título: 	Chronic aerobic exercise associated to low-dose L-NAME improves contractility without changing calcium handling in rat cardiomyocytes	
Autores: 	Luchi,T.C.; Coelho,P.M.; Cordeiro,J.P.; Assis,A.L.E.M.; Nogueira,B.V.; Marques,V.B.; dos Santos,L.; Lima-Leopoldo,A.P.; Lunz,W.; Leopoldo,A.S.	
Data: 	2020-01-01	
Ano: 	2020	
Palavras-chave: 	Nitric oxide; Aerobic exercise; Cardiac remodeling; Cardiomyocyte; Calcium.	
Resumo: 	Nitric oxide (NO) inhibition by high-dose NG-nitro-L-arginine methyl ester (L-NAME) is associated with several detrimental effects on the cardiovascular system. However, low-dose L-NAME increases NO synthesis, which in turn induces physiological cardiovascular benefits, probably by activating a protective negative feedback mechanism. Aerobic exercise, likewise, improves several cardiovascular functions in healthy hearts, but its effects are not known when chronically associated with low-dose L-NAME. Thus, we tested whether the association between low-dose L-NAME administration and chronic aerobic exercise promotes beneficial effects to the cardiovascular system, evaluating the cardiac remodeling process. Male Wistar rats were randomly assigned to control (C), L-NAME (L), chronic aerobic exercise (Ex), and chronic aerobic exercise associated to L-NAME (ExL). Aerobic training was performed with progressive intensity for 12 weeks; L-NAME (1.5 mg·kg-1·day-1) was administered by orogastric gavage. Low-dose L-NAME alone did not change systolic blood pressure (SBP), but ExL significantly increased SBP at week 8 with normalization after 12 weeks. Furthermore, ExL promoted the elevation of left ventricle (LV) end-diastolic pressure without the presence of cardiac hypertrophy and fibrosis. Time to 50% shortening and relaxation were reduced in ExL, suggesting a cardiomyocyte contractile improvement. In addition, the time to 50% Ca2+ peak was increased without alterations in Ca2+ amplitude and time to 50% Ca2+ decay. In conclusion, the association of chronic aerobic exercise and low-dose L-NAME prevented cardiac pathological remodeling and induced cardiomyocyte contractile function improvement; however, it did not alter myocyte affinity and sensitivity to intracellular Ca2+ handling.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2020000300611	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/1414-431x20198761	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.53 n.3 2020	
Fonte: 	info:eu-repo/semantics/openAccess