A New Role for Histamine H2-Receptors in Asthmatic Airways

Histamine tachyphylaxis develops with repeated inhalation of histamine in asthmatic subjects, and this appears to be due to the release of inhibitory prostaglandins. The purpose of this study was to determine whether histamine H2-receptors are also involved in the development of this protective effect in the airways. Seven subjects with mild asthma were studied on 2 days separated by at least 1 wk. On both days, three histamine inhalation tests …