calcimycin and exaprolol

Chloroquine liberated a relatively low amount of histamine from isolated rat mast cells. In a dose-dependent way, this drug inhibited histamine liberation from mast cells stimulated with compound 48/80, A23187, concanavalin A plus phosphatidylserine (Con A + PS) and abolished histamine liberation induced by exaprolol. The degranulation was decreased in cells stimulated with 48/80, Con A + PS and exaprolol. Chloroquine significantly inhibited the formation of thromboxane B2 in mast cells stimulated with 48/80, Con A + PS and A23187. We assume that chloroquine interferes with mast cells at a plasmic membrane site as well as intracellularly.

Topics: Adrenergic beta-Antagonists; Animals; Calcimycin; Chloroquine; Concanavalin A; Dose-Response Relationship, Drug; Histamine Release; Male; Mast Cells; p-Methoxy-N-methylphenethylamine; Phosphatidylserines; Propanolamines; Rats; Rats, Inbred Strains; Thromboxane B2