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.

• MeSH
• Adrenergic beta-Antagonists MeSH
• Calcimycin pharmacology   MeSH
• Chloroquine administration & dosage   pharmacology   MeSH
• Phosphatidylserines pharmacology   MeSH
• Rats, Inbred Strains MeSH
• Concanavalin A pharmacology   MeSH
• Rats MeSH
• Mast Cells drug effects   physiology   MeSH
• p-Methoxy-N-methylphenethylamine pharmacology   MeSH
• Propanolamines pharmacology   MeSH
• Thromboxane B2 biosynthesis   MeSH
• Histamine Release drug effects   MeSH
• Dose-Response Relationship, Drug MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Adrenergic beta-Antagonists MeSH
• Calcimycin MeSH
• Chloroquine MeSH
• exaprolol MeSH Browser
• Phosphatidylserines MeSH
• Concanavalin A MeSH
• p-Methoxy-N-methylphenethylamine MeSH
• Propanolamines MeSH
• Thromboxane B2 MeSH

Lipophilic exaprolol and hydrophilic atenolol differ in their interaction with mast cell membranes. Exaprolol, as compared with atenolol, significantly decreased 32P incorporation into, but increased arachidonic acid liberation from, membrane phospholipids. Moreover, exaprolol significantly decreased phosphate incorporation in compound 48/80 and ConA-PS treated cells and decreased thromboxane formation in stimulated cells. On the other hand, atenolol decreased significantly only arachidonate liberation from stimulated mast cells. These results corroborate to some extent the effect of exaprolol and atenolol on histamine liberation which correlates with their membrane perturbing properties.

• MeSH
• Atenolol pharmacology   MeSH
• Adrenergic beta-Antagonists pharmacology   MeSH
• Cell Membrane drug effects   metabolism   MeSH
• Phosphatidylserines pharmacology   MeSH
• Phosphates metabolism   MeSH
• Phospholipids metabolism   MeSH
• Rats, Inbred Strains MeSH
• Concanavalin A pharmacology   MeSH
• Rats MeSH
• Arachidonic Acid MeSH
• Arachidonic Acids metabolism   MeSH
• Mast Cells ultrastructure   MeSH
• Membrane Lipids metabolism   MeSH
• p-Methoxy-N-methylphenethylamine pharmacology   MeSH
• Propanolamines pharmacology   MeSH
• Phosphorus Radioisotopes metabolism   MeSH
• Thromboxane B2 biosynthesis   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Atenolol MeSH
• Adrenergic beta-Antagonists MeSH
• exaprolol MeSH Browser
• Phosphatidylserines MeSH
• Phosphates MeSH
• Phospholipids MeSH
• Concanavalin A MeSH
• Arachidonic Acid MeSH
• Arachidonic Acids MeSH
• Membrane Lipids MeSH
• p-Methoxy-N-methylphenethylamine MeSH
• Propanolamines MeSH
• Phosphorus Radioisotopes MeSH
• Thromboxane B2 MeSH