Effects of prostaglandin F2alpha on lung mechanics in nonasthmatic and asthmatic subjects

Abstract

Prostaglandins have been implicated as secondary pharmacologic mediators in allergic bronchial asthma. We have studied the effects of the intravenous infusion of prostaglandin F2alpha (PGF2alpha) on pulmonary mechanics in nonasthmatic and asthmatic volunteers. Before and during the infusion, measurements were made of total lung capacity and its subdivisions, static deflational transpulmonary pressure-volume relationships (PV), and maximal expiratory flow-volume curves with air and after a washing of an 80% helium-20% oxygen mixture. In both groups, PGF2alpha caused significant decreases in vital capacity and maximal flow and increases in residual volume. There were not significant differences between groups in either the absolute magnitude or the percent change in the variables, a result which may have been due to the similarity of the pulmonary mechanics in both groups prior to infusion. Changes in density dependence were bidirectional in both groups, indicating that relative contributions of large and small airways to flow limitation changed differently among individuals. The single between-group difference in responses noted was a leftward shift of the PV curve in the asthmatics, suggesting recoil of the lung which occurs in asthma.