title: Short-term in vivo inhibition of nitric oxide synthase with L-NAME influences the contractile function of single left ventricular myocytes in rats.
abstract: The main purpose of this study was to investigate the effects of short-term L-NAME treatment on the contractile function of left ventricle (LV) myocytes and the expression of proteins related to Ca(2+) homeostasis. Data from Wistar rats treated with L-NAME (L group, n = 20; 0.7 g/L in drinking water; 7 days) were compared with results from untreated controls (C group, n = 20). Cardiomyocytes from the L group showed increased (p < 0.05) fractional shortening (23%) and maximum rate of shortening (20%) compared with the C group. LV from the L group also showed increased (p < 0.05) expression of the ryanodine receptor 2 and Na(+)/Ca(2+) exchanger proteins (76% and 83%, respectively; p < 0.05). However, the L and C groups showed similar in vivo hemodynamic parameters of cardiac function. In conclusion, short-term NOS inhibition determines an increased expression of Ca(2+) regulatory proteins, which contributes to improving cardiomyocyte contractile function, preserving left ventricular function.
authors.affiliation: Department of Physiological Sciences, Federal University of Espírito Santo (UFES), Av. Marechal Campos, Vitória, ES, Brazil.
authors.forename: Wellington
authors.initials: W
authors.lastname: Lunz
authors.forename: Antônio José
authors.initials: AJ
authors.lastname: Natali
authors.forename: Miguel Araújo
authors.initials: MA
authors.lastname: Carneiro
authors.forename: Luciano
authors.initials: L
authors.lastname: Dos Santos Aggum Capettini
authors.forename: Marcelo Perim
authors.initials: MP
authors.lastname: Baldo
authors.forename: Matheus Ornelas
authors.initials: MO
authors.lastname: de Souza
authors.forename: Judson Fonseca
authors.initials: JF
authors.lastname: Quintão
authors.forename: Luiz Henrique Marchesi
authors.initials: LH
authors.lastname: Bozi
authors.forename: Virginia Soares
authors.initials: VS
authors.lastname: Lemos
authors.forename: José Geraldo
authors.initials: JG
authors.lastname: Mill
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051381:Rats; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics; D019831:Sodium-Calcium Exchanger / Q000378:metabolism
chemical_list: D019837:Ryanodine Receptor Calcium Release Channel; D019831:Sodium-Calcium Exchanger; D019001:Nitric Oxide Synthase; D002118:Calcium; D019331:NG-Nitroarginine Methyl Ester