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Fioresi,M.; Furieri,L.B.; Simões,M.R.; Ribeiro Junior,R.F.; Meira,E.F.; Fernandes,A.A.; Stefanon,I.; Vassallo,D.V.. |
We studied the effects of the acute administration of small doses of lead over time on hemodynamic parameters in anesthetized rats to determine if myocardial contractility changes are dependent or not on the development of hypertension. Male Wistar rats received 320 µg/kg lead acetateiv once, and their hemodynamic parameters were measured for 2 h. Cardiac contractility was evaluated in vitro using left ventricular papillary muscles as were Na+,K+-ATPase and myosin Ca2+-ATPase activities. Lead increased left- (control: 112 ± 3.7 vs lead: 129 ± 3.2 mmHg) and right-ventricular systolic pressures (control: 28 ± 1.2vs lead: 34 ± 1.2 mmHg) significantly without modifying heart rate. Papillary muscles were exposed to 8 µM lead acetate and evaluated 60 min later.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lead; Myocardial contractility; Ventricular pressure. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2013000200178 |
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Rossoni,L.V.; Amaral,S.M.C.; Vassallo,P.F.; França,A.; Oliveira,E.M.; Varner,K.J.; Mill,J.G.; Vassallo,D.V.. |
The available data suggests that hypotension caused by Hg2+ administration may be produced by a reduction of cardiac contractility or by cholinergic mechanisms. The hemodynamic effects of an intravenous injection of HgCl2 (5 mg/kg) were studied in anesthetized rats (N = 12) by monitoring left and right ventricular (LV and RV) systolic and diastolic pressures for 120 min. After HgCl2 administration the LV systolic pressure decreased only after 40 min (99 ± 3.3 to 85 ± 8.8 mmHg at 80 min). However, RV systolic pressure increased, initially slowly but faster after 30 min (25 ± 1.8 to 42 ± 1.6 mmHg at 80 min). Both right and left diastolic pressures increased after HgCl2 treatment, suggesting the development of diastolic ventricular dysfunction. Since HgCl2... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mercury; Arterial blood pressure; Ventricular pressure; Pulmonary circulation; Diastolic dysfunction; Cholinergic activity. |
Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000800009 |
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