COMPARISON OF THEOPHYLLINE AND ENPROFYLLINE EFFECTS ON HUMAN NEUTROPHIL SUPEROXIDE PRODUCTION

Abstract
1. We investigated effects of theophylline (widely used for the treatment of asthma) and enprofylline (a new xanthine derivative with negligible adenosine antagonism) on O2- production by human neutrophils with n-formyl-methionylleucyl-phenylalanine (FMLP) stimulation. 2. Therapeutic concentrations of theophylline (1–100 μmol/L) enhanced O2- production, maximally by 43.1 ± 24.4% at 30 μmol/L; the same concentrations of enprofylline inhibited O2- production. 3. When each agent was administered after pre-incubation with adenosine deaminase (ADA) (0.1 U/mL), O2- production was inhibited in a concentration-dependent manner in comparison with that under administration of ADA alone. 4. These results suggest that the difference of effects in the two xanthine derivatives at therapeutic concentrations might be due to the presence or absence of adenosine antagonism.