Sugar-specific inhibitory effects of wheat germ agglutinin and phytohemagglutinin-E4 on histamine release induced by basic secretagogues from rat peritoneal mast cells and their possible action sites.
The histamine release induced by compound 48/80, bradykinin or polyethylenimine with a molecular weight of 600 (PEI6) was inhibited by wheat germ agglutinin (WGA) and phytohemagglutinin E-subunits (PHA-E4), and the inhibition was specifically reversed by N-acetyl glucosamine and N-acetyl galactosamine, respectively. Concanavalin A (Con A) and phytohemagglutinin L-subunits (PHA-L4) did not inhibit the histamine release induced by compound 48/80, bradykinin or PEI6. The histamine release induced by substance P was also inhibited sugar-specifically by WGA and PHA-E4. The binding sites for compound 48/80, bradykinin, PEI6 and substance P, therefore, seemed to especially overlap each other. These binding sites were found to be glycoproteins having affinities to WGA and PHA-E4, but not to Con A and PHA-L4. The binding of WGA and PHA-E4 to the glycoproteins resulted in inhibition of the interaction between the basic secretagogues including bradykinin and substance P and their binding sites on the mast cells. The bindings of five lectins to mast cell glycoproteins were examined by lectin-blotting. Several glycoproteins, which had specific affinities to WGA and PHA-E4, but not to Con A and PHA-L4 were detected. We assumed that the binding sites for basic secretagogues which are coupled with histamine-releasing mechanisms exist among these glycoproteins. A 41-kDa protein (alpha-subunit of pertussis toxin-sensitive G protein) was not detected by WGA, suggesting that the binding sites for the basic secretagogues were not G proteins.
Suzuki-Nishimura
T
T
Department of Molecular Pharmacology, Meiji College of Pharmacy, Tokyo, Japan.
Nagaya
K
K
Matsuda
K
K
Uchida
M K
MK
Aoki
J
J
Umeda
M
M
Inoue
K
K
D000116:Acetylgalactosamine / Q000494:pharmacology; D000117:Acetylglucosamine / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites / Q000502:physiology; D001920:Bradykinin / Q000037:antagonists & inhibitors; D002367:Ricinus communis; D006636:Histamine Release / Q000187:drug effects*; D037102:Lectins; D008297:Male; D008407:Mast Cells / Q000187:drug effects*; D010529:Peritoneal Cavity / Q000166:cytology; D010835:Phytohemagglutinins; D037121:Plant Lectins; D010947:Plants, Toxic; D011094:Polyethyleneimine; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000494:pharmacology; D014909:Wheat Germ Agglutinins; D003189:p-Methoxy-N-methylphenethylamine
D037102:Lectins; D010835:Phytohemagglutinins; D037121:Plant Lectins; C017707:Ricinus communis agglutinin-1; D014909:Wheat Germ Agglutinins; C064103:phytohemagglutinin L4; D013373:Substance P; D003189:p-Methoxy-N-methylphenethylamine; D011094:Polyethyleneimine; D000116:Acetylgalactosamine; D001920:Bradykinin; D000117:Acetylglucosamine