%0 Journal Article
%T Nitric oxide alteration in the cardiovascular function by exercise training Altera  o do ¨®xido n¨ªtrico na fun  o cardiovascular pelo treinamento f¨ªsico
%A Arthur de Freitas Brand£¿o
%A Marli Cardoso Martins Pinge
%J Semina : Ci¨ºncias Biol¨®gicas e da Sa¨²de
%D 2007
%I Universidade Estadual de Londrina
%X Among the mechanisms of arterial pressure control, the humoral one carried out by the nitric oxide (NO) has aroused great scientific interest. The cardiovascular effects observed after the physical training are associated to an increase in the vascular structure, resting bradycardia and a post effort hypotension effect. The NO that is synthesized in endothelial cells from the L-arginine amino acid with the nitric oxide synthase (NOS) action is considered a powerful vaso-dilator. The NO has three enzymatic isoforms: the nNOS enzyme is present in the nervous cells, and the eNOS in the endothelial cells, both calciumdependent. On the other hand, the iNOS which is activated by immunological stimuli, is calciumindependent. In the central nervous system (CNS), the NO exerts an important role in the blood pressure control through sympathetic nervous system, inhibiting its activity and decreasing the vascular tonus. Moreover, the NO exerts an influence on the rostral ventrolateral medulla (RVLM), which is important in the modulation of the cardiovascular function. Studies that relate physical training and NO, noticed a significant increase in vasodilation after physical training in special population such as: hypertensives, obese, diabetic and cardiopath people, when compared with healthy individuals. In this sense, there seems to be a modulation of the physical training on the NO participation in the PA control, not only in the peripherical but also in the central level. New studies are still necessary to better elucidate this phenomenon. Dentre os mecanismos de controle da press o arterial, o controle humoral realizado pelo ¨®xido n¨ªtrico (NO) tem despertado grande interesse cient¨ªfico. Os efeitos cardiovasculares observados ap¨®s o treinamento f¨ªsico est o associados ao aumento da estrutura vascular, bradicardia de repouso e um efeito hipotensor ap¨®s esfor o. O NO, sintetizado em c¨¦lulas endoteliais a partir do amino¨¢cido Larginina com a a  o da enzima ¨®xido n¨ªtrico sintase (NOS), ¨¦ considerado um potente vasodilatador. O NO possui tr¨ºs isoformas enzim¨¢ticas: a enzima nNOS atua nas c¨¦lulas nervosas e a eNOS em c¨¦lulas endoteliais (ambas c¨¢lcio dependentes) e a iNOS, ¨¦ ativada por est¨ªmulos imunol¨®gicos e independente do ¨ªon c¨¢lcio. No sistema nervoso central (SNC), o NO possui importante papel no controle da press o sangu¨ªnea via sistema nervoso simp¨¢tico, pois inibe sua atividade e diminui seu t nus sobre os vasos. Al¨¦m disso, o NO exerce influ¨ºncia na regi o ventrolateral rostral medular (RVLM), importante na modula  o da fun  o cardiovascular. Estudos que r
%K ¨®xido n¨ªtrico
%K Vasodilata  o
%K Treinamento f¨ªsico
%K Press o arterial.
%U http://www.uel.br/revistas/uel/index.php/seminabio/article/view/3490