Glucagon-like peptide-1 does not mediate amylase release from AR42J cells.
In this study, AR42J pancreatic acinar cells were used to investigate if glucagon-like peptide-1 (GLP-1) or glucagon might influence amylase release and acinar cell function. We first confirmed the presence of GLP-1 receptors on AR42J cells by reverse trasncriptase-polymerase chain reaction (RT-PCR), Western blotting, and partial sequencing analysis. While cholecystokinin (CCK) increased amylase release from AR42J cells, GLP-1, alone or in the presence of CCK, had no effect on amylase release but both CCK and GLP-1 increased intracellular calcium. Similar to GLP-1, glucagon increased both cyclic adenosine monophosphate (cAMP) and intracellular calcium in AR42J cells but it actually decreased CCK-mediated amylase release (n = 20, P < 0.01). CCK stimulation resulted in an increase in tyrosine phosphorylation of several cellular proteins, unlike GLP-1 treatment, where no such increased phosphorylation was seen. Instead, GLP-1 decreased such protein phosphorylations. Genestein blocked CCK-induced phosphorylation events and amylase secretion while vanadate increased amylase secretion. These results provide evidence that tyrosine phosphorylation is necessary for amylase release and that signaling through GLP-1 receptors does not mediate amylase release in AR42J cells. J. Cell. Physiol. 181:470-478, 1999. Published 1999 Wiley-Liss, Inc.
Zhou
J
J
Diabetes Section, Gerontology Research Center, National Institute on Aging, National Institiutes of Health, Baltimore, Maryland 21224, USA.
Montrose-Rafizadeh
C
C
Janczewski
A M
AM
Pineyro
M A
MA
Sollott
S J
SJ
Wang
Y
Y
Egan
J M
JM
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000681:Amylases / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D020013:Calcium Signaling / Q000187:drug effects; D002460:Cell Line; D002766:Cholecystokinin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D005934:Glucagon / Q000494:pharmacology* / Q000502:physiology; D052216:Glucagon-Like Peptide 1; D000067757:Glucagon-Like Peptide-1 Receptor; D010179:Pancreas / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D010446:Peptide Fragments / Q000494:pharmacology* / Q000502:physiology; D010766:Phosphorylation; D011498:Protein Precursors / Q000494:pharmacology* / Q000502:physiology; D051381:Rats; D018027:Receptors, Glucagon / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014443:Tyrosine / Q000378:metabolism
D017931:DNA Primers; C000593835:Glp1r protein, rat; D000067757:Glucagon-Like Peptide-1 Receptor; D010446:Peptide Fragments; D011498:Protein Precursors; D018027:Receptors, Glucagon; D015124:8-Bromo Cyclic Adenosine Monophosphate; D014443:Tyrosine; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; D002766:Cholecystokinin; D000242:Cyclic AMP; D000681:Amylases