Sulfur dioxide induced airway hyperreactivity in allergic sheep

✍ Scribed by William M. Abraham; William Oliver Jr.; Matthew J. Welker; Maryann King; Gillette A. Chapman; Lawrence Yerger; David R. Maurer; Marek Sielczak; Adam Wanner; Marvin A. Sackner

• Book ID: 102698720
• Publisher: John Wiley and Sons
• Year: 1980
• Tongue: English
• Weight: 1021 KB
• Volume: 1
• Category: Article
• ISSN: 0271-3586
• DOI: 10.1002/ajim.4700010315

✦ Synopsis

The effects of a four-hour exposure (via a Plexiglas hood) to sulfur dioxide (SO,) on airway reactivity was studied in both normal and allergic conscious sheep. Allergic sheep were defined as animals in whom inhalation of Ascuris s u m extract resulted in an increase in mean pulmonary flow resistance (RL). Airway reactivity (ARL) was assessed by measuring the increase in RL after 18 breaths of 0.25% carbachol, from an initial value obtained after 18 breaths of buffered saline. R L and ARL were determined prior to, immediately after and 24 hours following SOz exposure in three groups of sheep: six normal sheep exposed to 5 ppm SO2 (group A); six normal sheep exposed to 10 ppm SO2 (group B) and seven allergic sheep exposed to 5 ppm SOz (group C). RL was not affected by SOz exposure in any group but both groups B and C showed increases in ARL 24 hours after exposure. Since the increase in ARL was greater in group C than in either groups A or B, we conclude that allergic sheep have enhanced susceptibility to the injurious airway effects of SOz.