Tracheal instillation of urban PM2.5 suspension promotes acute cardiac polarization changes in rats

Abstract

The mechanisms by which PM 2.5 increases cardiovascular mortality are not fully identified. Autonomic alterations are the current main hypotheses. Our objective was to determine if PM 2.5 induces acute cardiac polarization alterations in healthy Wistar rats. PM 2.5 samples were collected on polycarbonate filters. Solutions containing 10, 20, and 50 μg PM 2.5 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 < 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 < 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 < 0.001). QRS interval duration decreased at 20 and 50 μg in relation to blank filter solution and 10 μg (P < 0.001). QT interval duration decreased significantly (P < 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 < 0.001). PM 2.5 induced reduced cardiac conduction time, within a short period, indicating that depolarization occurs more rapidly across ventricular tissue.

A systematic review of the physical and chemical characteristics of pollutants from biomass burning and combustion of fossil fuels and health effects in Brazil

“…Ninety articles (66%) deal with the adverse respiratory effects of air pollution of which 54 (60%) were selected 21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,…”

Effects of Exposure to Total Particulate Matter of Cashew Nuts Shell in the Respiratory System of Mice with Chronic Obstructive Pulmonary Disease

“…After sonication, the filters were again placed in the oven at 50ºC for 24 hours and weighed. The efficiency of the extraction of the particles is calculated by the difference between the masses of the filters before and after the collection process (MAATZ et al, 2009). The final particle volume ratio was 1:1 (1 μg:1 μL), where we used 30 μg of TPM mass in 30 μL of the final solution.…”

Toxicidade cardiovascular e inflamatória aguda induzida pela inalação de partículas dos combustíveis diesel e biodiesel

“…Dentre os poluentes atmosféricos, o MP 2,5 e o MP 0,1 tem sido amplamente estudados, pois possuem a capacidade de penetrar nas regiões mais distais do sistema respiratório, se deslocando para o sistema circulatório, gerando efeitos adversos nos órgãos atingidos, como coração (Rivero et al, 2005a(Rivero et al, , 2005bDamaceno-Rodrigues et al, 2009;Maatz et al, 2009), pulmão (Cançado et al, 2006;Laks et al, 2008), cérebro (Oberdorster et al, 2004, Hougaard et al, 2009Yokota et al, 2009), rim (Theis et al, 2008;Dündar et al, 2004), fígado (Araujo et al, 2008), aparelho reprodutor (Veras et al, 2008 Durante a exposição, a isquemia do miocárdio foi quantificada pela análise do segmento ST, e após 6 horas da exposição, a função fibrinolítica e vasomotora foi avaliada. Os autores demonstraram aumento da FC em ambas às exposições (ar filtrado e queima do diesel) e a exposição ao diesel não agravou a disfunção vasomotora pré-existente, concluindo que a queima do diesel promove isquemia do miocárdio e inibe a capacidade endógena fibrinolítica.…”

“…Estudos controlados em humanos (Liao et al, 1999;Devlin et al, 2003;Brook et al, 2004;Park et al, 2005;Adar et al, 2007) e experimentais (Rivero et al, 2005a(Rivero et al, , 2005bMaatz et al, 2009;Pereira et al, 2007) (Rhoden et al, 2005) e/ou aumento do tônus vagal parassimpático (Pope et al, 1999).…”

“…Estudos recentes demonstraram que através da instilação intratraqueal aguda do PM 2,5 em ratos Wistar, na dose de 100 µg/mL e 500 µg/mL (Rivero et al, 2005a) e na dose de 50 µg/mL (Maatz et al, 2009) Em contrapartida, a literatura apresenta inúmeros estudos experimentais de toxicidade da queima do diesel (Campen et al, 2005;Anselme et al, 2007;Gottipolu et al, 2009;Saxena et al, 2009;Sunil et al, 2009) e de exposição controlada em humanos Lucking et al, 2008;Peretz et al, 2008aPeretz et al, , 2008bLangrish et al, 2009 Lucking et al, 2008;Langrish et al, 2009), a reatividade vascular (Peretz et al, 2008a) e a VFC (Peretz et al, 2008b). O compostos orgânicos da queima do diesel, são descritos como geradores de inflamação e estresse oxidativo (Ball et al, 2000;Saldiva et al, 2002;Nemmar et al, 2009;Sunil et al, 2009 Outros estudos também demonstraram que o B100 reduz as emissões de MP, CO e HC e aumenta as emissões de NO X (parâmetro não avaliado neste estudo) (EPA, 2002a;Graboski et al, 2003;Zou et al, 2003;Yuan et al, 2007;Lapuerta et al, 2008a).…”