Mast cell activation by pedicellarial toxin of sea urchin, Toxopneustes pileolus.
Pedicellarial toxin, partially purified from the sea urchin Toxopneustes pileolus, dose-dependently and time-dependently caused histamine release from rat peritoneal mast cells. Pedicellarial toxin induced a rapid initial rise in [Ca2+]i within several seconds which was followed by a further slower increase of [Ca2+]i (second rise). The toxin induced a dose-dependent formation of inositol 1,4,5-triphosphate (IP3) as well as the histamine release in mast cells. Furthermore, the toxin stimulated phosphoinositide-specific phospholipase C (PI-PLC) activity in mast cell membranes. 2-Nitro-4-carboxyphenyl-N,N-diphenylcarbamate (NCDC), a PLC inhibitor, inhibited the activation of PI-PCL induced by pedicellarial toxin. Cholera toxin inhibited pedicellarial toxin-induced histamine release, whereas pretreatment of pertussis toxin failed to inhibit it. These results suggest that pedicellarial toxin from T. pileolus activates PI-PCL and the stimulation of PI turnover may lead to the release of IP3 into the cytoplasm, resulting in histamine release from rat mast cells.
Takei
M
M
La Jolla Institute for Allergy and Immunology, CA 92037.
Nakagawa
H
H
Endo
K
K
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002219:Carbamates / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D002772:Cholera Toxin / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D006636:Histamine Release / Q000187:drug effects; D015544:Inositol 1,4,5-Trisphosphate / Q000096:biosynthesis; D008297:Male; D008387:Marine Toxins / Q000037:antagonists & inhibitors / Q000493:pharmacokinetics / Q000494:pharmacology*; D008407:Mast Cells / Q000187:drug effects*; D010529:Peritoneal Cavity; D048448:Phenylcarbamates; D051381:Rats; D017208:Rats, Wistar; D012617:Sea Urchins / Q000737:chemistry*; D010738:Type C Phospholipases / Q000378:metabolism
D002219:Carbamates; D008387:Marine Toxins; D048448:Phenylcarbamates; C025508:2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate; C066979:contractin A; D015544:Inositol 1,4,5-Trisphosphate; D002772:Cholera Toxin; D010738:Type C Phospholipases; D002118:Calcium