Effect of a novel antiallergic drug, pemirolast, on activation of rat peritoneal mast cells: inhibition of exocytotic response and membrane phospholipid turnover.
The effects of a potent antiallergic drug, pemirolast (TBX), on activation of signal-transducing phospholipase C and A2, were examined in rat peritoneal mast cells. TBX at concentrations between 10(-7) and 10(-5) g/ml effectively inhibited degranulation in response to both antigen and compound 48/80. At the same concentrations the drug markedly suppressed the formation of 1,2-diacylglycerol and phosphatidic acid, and the decrease in phosphatidylinositol, suggesting the prevention of phospholipase C activation. The blockade of phospholipase A2 was suggested by the decrease in agonists-induced arachidonic acid liberation. These results indicate that TBX may exert its inhibitory effects on mast cells, at least in part, by preventing the activation of signal-transducing phospholipases.
Fujimiya
H
H
Department of Otolaryngology, Gifu University School of Medicine, Japan.
Nakashima
S
S
Miyata
H
H
Nozawa
Y
Y
D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology; D001200:Ascaris / Q000276:immunology; D015550:Cell Degranulation / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism; D005089:Exocytosis / Q000187:drug effects / Q000276:immunology*; D006633:Histamine Antagonists / Q000494:pharmacology*; D006636:Histamine Release; D008407:Mast Cells / Q000187:drug effects* / Q000276:immunology; D010529:Peritoneal Cavity; D010743:Phospholipids / Q000378:metabolism*; D011725:Pyridines / Q000494:pharmacology*; D011744:Pyrimidinones / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
D000947:Antigens, Helminth; D006633:Histamine Antagonists; D010743:Phospholipids; D011725:Pyridines; D011744:Pyrimidinones; C055139:pemirolast; D012701:Serotonin; D003189:p-Methoxy-N-methylphenethylamine