{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T06:24:12Z","timestamp":1774938252042,"version":"3.50.1"},"reference-count":0,"publisher":"Oxford University Press (OUP)","issue":"4","license":[{"start":{"date-parts":[[1985,4,1]],"date-time":"1985-04-01T00:00:00Z","timestamp":481161600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[1985,4,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>We sought to determine whether 0.25 ppm sulfur dioxide in filtered air causes broncho-constriction when inhaled by freely breathing, heavily exercising, asthmatic subjects. Nineteen asthmatic volunteers exercised at 750 kilogram meters\/min for 5 min in an exposure chamber that contained filtered air at ambient temperature and humidity or, on another day, filtered air plus 0.25 ppm sulfur dioxide. The order of exposure to sulfur dioxide and to filtered air alone was randomized, and the experiments were double-blinded. Specific airway resistance, measured by constant-volume, whole-body plethysmography, increased from 6.38 \u00b1 2.07 cm H2O \u00d7 s (mean \u00b1 SD) before exercise to 11.32 \u00b1 8.97 after exercise on days when subjects breathed filtered air alone and from 5.70 \u00b1 1.93 to 13.33 \u00b1 7.54 on days when subjects breathed 0.25 ppm sulfur dioxide in filtered air. The increase in specific airway resistance on days when subjects breathed 0.25 ppm sulfur dioxide was only slightly greater than on days when they breathed filtered air, but the difference was significant. To determine whether 0.25 ppm sulfur dioxide causes greater bronchoconstriction in asthmatic subjects exercising more vigorously, 9 subjects then repeated the experiment exercising at 1,000 instead of 750 kilogram meters\/min. Specific airway resistance increased from 6.71 \u00b1 2.25 to 13.59 \u00b1 7.57 on days when subjects breathed filtered air alone and from 5.23 \u00b1 1.23 to 12.54 \u00b1 6.17 on days they breathed 0.25 ppm sulfur dioxide in filtered air. The increase in specific airway resistance on the 2 days was not significantly different. We conclude that 0.25 ppm sulfur dioxide may cause bronchoconstriction in freely breathing, heavily exercising subjects with asthma, but that the effect is small and is largely overshadowed by bronchoconstrictor effect of exercise alone.<\/jats:p>","DOI":"10.1164\/arrd.1985.131.4.659","type":"journal-article","created":{"date-parts":[[2019,11,7]],"date-time":"2019-11-07T19:18:42Z","timestamp":1573154322000},"page":"659-661","source":"Crossref","is-referenced-by-count":23,"title":["Effect of 0.25 ppm Sulfur Dioxide on Airway Resistance in Freely Breathing, Heavily Exercising, Asthmatic Subjects"],"prefix":"10.1093","volume":"131","author":[{"given":"Robert A.","family":"Bethel","sequence":"first","affiliation":[{"name":"Recipient of Pulmonary Faculty Training Grant No. HL-07159 from the National Institutes of Health"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dean","family":"Sheppard","sequence":"additional","affiliation":[{"name":"University of California Cardiovascular Research Institute Departments of Medicine and Physiology \u00a0 San Francisco, California"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Barbara","family":"Geffroy","sequence":"additional","affiliation":[{"name":"University of California Cardiovascular Research Institute Departments of Medicine and Physiology \u00a0 San Francisco, California"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Elizabeth","family":"Tam","sequence":"additional","affiliation":[{"name":"University of California Cardiovascular Research Institute Departments of Medicine and Physiology \u00a0 San Francisco, California"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jay A.","family":"Nadel","sequence":"additional","affiliation":[{"name":"University of California Cardiovascular Research Institute Departments of Medicine and Physiology \u00a0 San Francisco, California"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Homer A.","family":"Boushey","sequence":"additional","affiliation":[{"name":"University of California Cardiovascular Research Institute Departments of Medicine and Physiology \u00a0 San Francisco, California"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"286","published-online":{"date-parts":[[1985,4,1]]},"container-title":["American Review of Respiratory Disease"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/ajrccm\/article-pdf\/131\/4\/659\/67667339\/ajrccm_131_4_659.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ajrccm\/article-pdf\/131\/4\/659\/67667339\/ajrccm_131_4_659.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T04:55:56Z","timestamp":1774932956000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/ajrccm\/article\/131\/4\/659\/8561811"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1985,4,1]]},"references-count":0,"journal-issue":{"issue":"4","published-online":{"date-parts":[[1985,4,1]]},"published-print":{"date-parts":[[1985,4,1]]}},"URL":"https:\/\/doi.org\/10.1164\/arrd.1985.131.4.659","relation":{},"ISSN":["0003-0805"],"issn-type":[{"value":"0003-0805","type":"print"}],"subject":[],"published-other":{"date-parts":[[1985,4]]},"published":{"date-parts":[[1985,4,1]]}}}