title: Immediate effects of particulate air pollutants on heart rate and respiratory rate in hypertensive rats.
abstract: Time-series studies have shown that the lag time between elevated particulate air pollution (PM) and increases in cardiovascular-related hospital admissions and death is very short 1 d or less. If PM does cause serious cardiovascular effects shortly after exposure, one would expect to see some physiological change during exposure. In this study, spontaneously hypertensive rats (SHRs) with surgically implanted blood pressure transmitters were exposed to concentrated ambient PM (CAPS) for 4 h to determine whether CAPS inhalation causes immediate effects. The rats were also exposed to sulfuric acid aerosols because acid is one of the components of PM that could potentially activate irritant receptors and cause effects during exposure. Exposure to CAPS caused a striking decrease in respiratory rate that was apparent soon after the start of exposure and stopped when exposure to CAPS ceased. The decrease in respiratory rate was accompanied by a decrease in heart rate. Exposure of the same rats to fine-particle-size sulfuric acid aerosol also caused a significant decrease in respiratory rate similar to the effects of CAPS. Ultrafine acid had the opposite effect on respiratory rate compared to CAPS. Because acids have been shown to evoke sensory irritant responses in rodents, the similarity between the effects of fine acid aerosol and CAPS suggests that CAPS activates airway-irritant receptors during exposure.
authors.affiliation: Department of Environmental Medicine, NYU School of Medicine, Tuxedo, NY 10987, USA. nadziejko@env.med.nyu.edu
authors.forename: Chrinstine
authors.initials: C
authors.lastname: Nadziejko
authors.forename: Kaijie
authors.initials: K
authors.lastname: Fang
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Nadziejko
authors.forename: Sandy Pais
authors.initials: SP
authors.lastname: Narciso
authors.forename: Mianhua
authors.initials: M
authors.lastname: Zhong
authors.forename: Lung Chi
authors.initials: LC
authors.lastname: Chen
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000009:adverse effects*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D003971:Diastole / Q000502:physiology; D004195:Disease Models, Animal; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology*; D019570:Inhalation Exposure; D008297:Male; D008955:Models, Cardiovascular; D010316:Particle Size; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012119:Respiration / Q000187:drug effects*; D013464:Sulfuric Acids / Q000009:adverse effects; D013599:Systole / Q000502:physiology; D013997:Time Factors
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D013464:Sulfuric Acids; C033158:sulfuric acid