sincalide and acrylodan

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.

Topics: 2-Naphthylamine; Animals; Fluorescent Dyes; Intracellular Signaling Peptides and Proteins; Kinetics; Male; Membrane Proteins; Mice; Myristoylated Alanine-Rich C Kinase Substrate; Pancreas; Patch-Clamp Techniques; Protein Kinase C; Proteins; Sincalide; Spectrometry, Fluorescence