Possible involvement of protein kinase C in mediating gastrin-induced response in rat colonic epithelium.
We examined the potential role of protein kinase C in signal transduction induced by gastrin's stimulation of rat colonic epithelium. Protein synthesis ([35S]methionine incorporation into protein) and enzyme activity (decrease in the cytosolic activity) were measured following epithelial stimulation with gastrin. Gastrin (10 nM) increased [35S]methionine incorporation into protein to 265% above maintenance level. The effect of gastrin was comparable to the stimulation induced by phorbol 12-myristate, 13-acetate (PMA), a strong activator of protein kinase C. The increase in protein synthesis induced by gastrin was totally abolished by 1-(5-isoquinolinyl)-2-methylpiperazine, an inhibitor of protein kinase C activity. Gastrin also decreased the cytosolic activity of the enzyme, an index of its activation and subsequent translocation to other cellular compartments. Therefore, we conclude that gastrin may be acting through a protein kinase C mechanism.
Yassin
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Krancer Center for Inflammatory Bowel Disease Research, Division of Gastroenterology, Hahnemann University, Philadelphia, PA 19102.
Murthy
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D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000704:Analysis of Variance; D000818:Animals; D003106:Colon / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D004848:Epithelium / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D005755:Gastrins / Q000494:pharmacology*; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D008715:Methionine / Q000378:metabolism; D010879:Piperazines / Q000494:pharmacology*; D014176:Protein Biosynthesis; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D005755:Gastrins; D007546:Isoquinolines; D010879:Piperazines; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D008715:Methionine; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate