AN ACCELERATED INCREASE OF PLASMA ADRENOMEDULLIN IN ACUTE ASTHMA

A novel vasorelaxant peptide, adrenomedullin (AM), has been isolated f rom the acid extract of human pheochromocytoma. We have recently Shown that AM inhibits histamine- and acetylcholine-induced bronchoconstric tion in anesthetized guinea pigs in vivo, and this bronchodilatory eff ect is long-lasting. Here, we measured plasma AM concentrations in nin e patients with an acute attack of bronchial asthma. The results were compared with values in 30 age-matched normal control subjects and sev en age-matched stable asthmatic patients. The mean AM concentrations o f patients with an acute asthma attack (98 +/- 22 pg/mL) were clearly higher than those of normal control subjects (18 +/- 2 pg/mL) and stab le asthmatic patients (21 +/- 3 pg/mL). Reverse-phase high-performance liquid chromatography (HPLC) showed that the major component of plasm a immunoreactive AM in patients with an asthma attack and in normal su bjects equally corresponded to authentic human AM(1-52). our results s uggest that plasma AM is markedly increased,in many of the patients du ring an acute attack of bronchial asthma, but it is not observed in st able asthmatic patients. Although this report is preliminary, the obse rved increase of circulating AM during an acute asthma attack may repr esent a compensatory mechanism against the bronchoconstriction, probab ly through its bronchodilatory action. Copyright (C) 1996 by W.B. Saun ders Company