Possible involvement of cyclic AMP in inflammation induced by a surfactant.

Alkyldimethylbenzylammonium chloride (alkyl-DBAC), a cationic surfactant, produces acute exudative inflammation accompanied by an enhancement of energy metabolism. The mechanism of metabolic changes, consequently the cyclic AMP level and the effects of certain drugs were determined in the gastrocnemius muscles of rats in which acute exudative inflammation had been induced by intramuscular injections of alkyl-DBAC. A transient increase in the cyclic AMP level was noted at 15 to 30 minutes after the injection of alkyl-DBAC, and this elevation was antagonized by chlorpromazine, diphenhydramine, promethazine, aspirin and indomethacin. The time course of increasing tendency in the cyclic AMP level after the injection of histamine closely paralleled that of alkyl-DBAC. These results suggest that cyclic AMP may be involved in the metabolic changes with inflammation induced by alkyl-DBAC.