Soybean agglutinin stimulated cholecystokinin release from cultured rabbit jejunal cells requires calcium influx via L-type calcium channels.
We have studied the mechanism of soybean agglutinin (SBA) mediated cholecystokinin (CCK) release in enriched cultured cholecystokinin-secreting cells. 12-O-Tetradecanoylphorbol-13-acetate 1 mM significantly stimulated release of CCK-like-immunoreactivity (CCK-LI) by 55%+/-17% (p < 0.05), which was blocked by the protein kinase C inhibitor staurosporine 100 nM. Forskolin 10 mM stimulated CCK-LI by 82%+/-12% (p < 0.05) and this was inhibited by somatostatin 1 nM. 1-Phenylalanine 20 mM and Bay K 8644 1 mM stimulated CCK-LI by 69%+/-22% and 60%+/-19% respectively (p < 0.05), these responses were completely abolished by the L-type calcium channel antagonist verapamil 10 mM. SBA 10 and 100 microg/ml stimulated CCK-LI by 65%+/-22% and 74%+/-24% respectively (p < 0.05). The effect of SBA was inhibited by verapamil and N-acetylgalactosamine. We conclude that SBA stimulates CCK-LI through calcium flux via L-type calcium channels.
Jordinson
M
M
Department of Gastroenterology, Imperial College School of Medicine, Hammersmith Hospital, London.
Beales
I L
IL
Calam
J
J
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D020746:Calcium Channels, L-Type; D002469:Cell Separation; D002478:Cells, Cultured; D002766:Cholecystokinin / Q000276:immunology / Q000378:metabolism*; D005576:Colforsin / Q000494:pharmacology; D004789:Enzyme Activation; D007583:Jejunum / Q000166:cytology / Q000187:drug effects*; D037102:Lectins / Q000494:pharmacology*; D008297:Male; D010649:Phenylalanine / Q000494:pharmacology; D037121:Plant Lectins; D011493:Protein Kinase C / Q000378:metabolism; D011817:Rabbits; D011863:Radioimmunoassay; D013004:Somatostatin / Q000494:pharmacology; D030262:Soybean Proteins; D019311:Staurosporine / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology; D010835:Phytohemagglutinins
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D000262:Adenylyl Cyclases; D002118:Calcium; D015220:Calcium Channels; D020746:Calcium Channels, L-Type; D002766:Cholecystokinin; D005576:Colforsin; D037102:Lectins; D010649:Phenylalanine; D037121:Plant Lectins; D011493:Protein Kinase C; D013004:Somatostatin; D030262:Soybean Proteins; D019311:Staurosporine; D014700:Verapamil; C028824:soybean lectin; D010835:Phytohemagglutinins