Effect of salmeterol on polymorphonuclear leukocyte (PMNL) chemiluminescence in vitro

Although beta-agonists remain an important aspect of the treatment of asthma, their role has recently been questioned. Salmeterol has recently been developed as a beta-agonist with prolonged bronchodilator action. Using lucigenin-enhanced chemiluminescence, we have shown that salmeterol inhibits this aspect of phagocyte function in vitro in a concentration-dependent manner. However, salmeterol differs from classical beta 2-agonists in that at concentrations between 10(-5) and 10(-3) mol/L, its effects on phagocytes cannot be completely reversed by washing the cells or by propranolol. The effects on phagocytes may not therefore be explicable on the basis of beta-adrenergic mechanisms alone.