Altered susceptibility to viral respiratory infection during short-term exposure to nitrogen dioxide.
نویسندگان
چکیده
The studies reported here focus on the relation of nitrogen dioxide exposure to susceptibility to viral respiratory infection in a murine model of pneumonia, created by intratracheal inoculation of an endogenous murine pathogen, mouse cytomegalovirus. The purpose of this work is to clarify the potential role of nitrogen dioxide exposure in the pathogenesis of viral infection of the lower respiratory tract. Previous human epidemiologic studies have presented conflicting information about the relationship of nitrogen dioxide to acute, self-limited episodes of respiratory illness, which are characteristic of viral respiratory infection. Some studies have found an association between exposure to elevated ambient levels of nitrogen dioxide and increased occurrence of acute respiratory illness. In one study this association was found to be strongest in children in the first two years of life. However, other epidemiologic studies have failed to observe this relation. To determine if there is scientific evidence for the possible relation of nitrogen dioxide exposure to human respiratory infection, our studies were performed to assess the impact of nitrogen dioxide on respiratory tract susceptibility to initial, or primary, infection, as well as to recurrent infection, or reinfection, with the identical virus. The latter mechanism of viral respiratory infection is of particular interest, since reinfection is a common method for the development of infection of the lower respiratory tract during early childhood. Outbred CD-1 mice were exposed to either air or nitrogen dioxide for six hours a day on two consecutive days prior to inoculation with murine cytomegalovirus, and then were reexposed to the same level of nitrogen dioxide for six hours a day on four consecutive days, beginning the day after viral inoculation. Susceptibility to primary infection was determined by inoculating animals with an amount of virus (10(2) plaque-forming units) that is too small to produce viral infection in the lungs of normal animals. Mice exposed to 5 parts per million (ppm) nitrogen dioxide routinely developed viral replication in the lung and histologic evidence of pneumonitis after inoculation with this amount of virus, whereas air-exposed animals did not. Most importantly, animals exposed to 5 ppm nitrogen dioxide could be infected with a viral inoculum that was 100-fold smaller than that required to consistently produce viral infection in air-exposed mice. Enhanced susceptibility to infection was found after exposure to 5 ppm nitrogen dioxide, but was not observed with exposure to 2.5 or 1 ppm nitrogen dioxide.(ABSTRACT TRUNCATED AT 400 WORDS)
منابع مشابه
Number of total mortality, cardiovascular mortality and Chronic Obstructive Pulmonary Disease due to exposure with Nitrogen dioxide in Tehran during 2005-2014
Background & Aims: Air pollution has adverse effects on human health and cause various diseases including cardiovascular disease and respiratory. Therefore this study with aim of study of Number of total mortality, cardiovascular mortality and Chronic Obstructive Pulmonary Disease due to exposure with Nitrogen dioxide in Tehran during 2005-2014 were performed. Materials & Methods: This ...
متن کاملRespiratory effects associated with indoor nitrogen dioxide exposure in children.
BACKGROUND The human health effects of exposure to indoor nitrogen dioxide (NO2) are unclear, and few studies have examined the effects of short-term peak levels of exposure. METHODS The association between indoor exposure to NO2 and respiratory illness was examined in 388 children aged 6-11 years. The NO2 levels were monitored during winter in 41 classrooms, from four schools with unflued ga...
متن کاملSystematic Review and Meta-Analysis of the Association between Ambient Nitrogen Dioxide and Respiratory Disease in China
Objective: This study aimed to assess the quantitative effects of short-term exposure of ambient nitrogen dioxide (NO₂) on respiratory disease (RD) mortality and RD hospital admission in China through systematic review and meta-analysis. Methods: A total of 29 publications were finally selected from searches in PubMed, Web of Science, CNKI and Wanfang databases. Generic inverse variance method ...
متن کاملEffect of oxidant air pollutants on the respiratory system: insights from experimental animal research.
In the present paper, we have reviewed experimental animal studies on the effects of the two most important oxidant airborne pollutants, nitrogen dioxide and ozone, on the respiratory system. The toxic effects depend on concentration and length of exposure, and are generally similar for both oxidants, with ozone operative at lower concentrations. High doses of both oxidants cause death due to l...
متن کاملDoes urban asthma exist? How climatic changes and urban air pollution intervene on asthma and respiratory allergy
How bad is living in a city for asthma? Several investigations have indicated that individuals living in cities have a higher risk of suffering from asthma and allergies compared to those living in the countryside, this being due to several factors. Besides the fact that individual susceptibility varies between urban and rural settings, there are environmental factors that are typical of living...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Research report
دوره 24 شماره
صفحات -
تاریخ انتشار 1989