Data/hora: 04/06/2024 01:11:43

Provedor de dados: | Brazilian Journal of Medical and Biological Research
País: | Brazil
Título: | Tracheal instillation of urban PM2.5 suspension promotes acute cardiac polarization changes in rats
Autores: | Maatz,L.F.; Wood,G.J.A.; Rivero,D.H.R.F.; Saldiva,P.H.N.
Data: | 2009-02-01
Ano: | 2009
Palavras-chave: | ECG alterations; Particulate matter; PM2.5; Wave segments; Tracheal instillation; Cardiovascular disease.
Resumo: | The mechanisms by which PM2.5 increases cardiovascular mortality are not fully identified. Autonomic alterations are the current main hypotheses. Our objective was to determine if PM2.5 induces acute cardiac polarization alterations in healthy Wistar rats. PM2.5 samples were collected on polycarbonate filters. Solutions containing 10, 20, and 50 µg PM2.5 were administered by tracheal instillation. P wave duration decreased significantly at 20 µg (0.99 ± 0.06, 0.95 ± 0.06, and 0.96 ± 0.07; P &lt; 0.001), and 50 µg (0.98 ± 0.06, 0.98 ± 0.07, and 0.96 ± 0.08; 60, 90 and 120 min, respectively) compared to blank filter solution (P &lt; 0.001). PR interval duration decreased significantly at 20 µg (0.99 ± 0.06, 0.98 ± 0.07, and 0.97 ± 0.08) and 50 µg (0.99 ± 0.05, 0.97 ± 0.0, and 0.95 ± 0.05; 60, 90, and 120 min, respectively) compared to blank filter and 10 µg (P &lt; 0.001). QRS interval duration decreased at 20 and 50 µg in relation to blank filter solution and 10 µg (P &lt; 0.001). QT interval duration decreased significantly (P &lt; 0.001) with time in animals receiving 20 µg (0.94 ± 0.12, 0.88 ± 0.14, and 0.88 ± 0.11) and 50 µg (1.00 ± 0.13; 0.97 ± 0.11 and 0.98 ± 0.16; 60, 90 and 120 min, respectively) compared to blank filter solution and 10 µg (P &lt; 0.001). PM2.5 induced reduced cardiac conduction time, within a short period, indicating that depolarization occurs more rapidly across ventricular tissue.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009000200009
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2009000200009
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.42 n.2 2009
Fonte: | info:eu-repo/semantics/openAccess