Cholecystokinin-octapeptide affects the fluorescence signal of a single pancreatic acinar cell loaded with the acrylodan-labelled MARCKS peptide, a protein kinase C substrate.
We used a fluorescent derivative of the myristoylated, alanine-rich C kinase substrate (MARCKS) peptide as a probe for protein kinase C (PKC) activation by cholecystokinin-octapeptide (CCK-8) in isolated pancreatic acinar cell pairs. The diffusion of the acrylodan-labelled MARCKS-peptide into the cell interior could be monitored by the increase of fluorescence in the whole-cell patch-clamp configuration. Addition of 10 pM CCK-8 to the bath induced repetitive fluctuations of the fluorescent signal in the time range of 4-5 min. With 1 nM CCK-8 a sustained decrease of the signal was observed. Addition of polymyxin B, a specific inhibitor of PKC activation, to the pipette filling solution suppressed the CCK-8-induced change of fluorescence. The data indicate activation of PKC by CCK-8 in pancreatic acinar cells and could be compared with the previously studied CCK-8-induced gap junction uncoupling.
Ngezahayo
A
A
University of Tübingen, Institute of Physiology I, Germany.
Lang
F
F
Kolb
H A
HA
D015081:2-Naphthylamine / Q000031:analogs & derivatives*; D000818:Animals; D005456:Fluorescent Dyes; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D008297:Male; D008565:Membrane Proteins; D051379:Mice; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D010179:Pancreas / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D012844:Sincalide / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence
D005456:Fluorescent Dyes; D047908:Intracellular Signaling Peptides and Proteins; C000619711:Marcks protein, mouse; D008565:Membrane Proteins; D011506:Proteins; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; C038518:acrylodan; D015081:2-Naphthylamine; D011493:Protein Kinase C; D012844:Sincalide