FLUORESCENCE MICROSCOPIC STUDIES AND FLOW CYTOMETRIC MEASUREMENTS OF LECTIN AND HORMONE-BINDING TO ISOLATED RAT PANCREATIC ACINAR-CELLS

The binding of fluorescence-labelled lectins and a fluorescence-marked hormone to the cell surface of isolated rat pancreatic acinar cells w as studied by light microscopy and flow cytometric measurements. The p ancreatic acinar cells were prepared by collagenase digestion. The flu orescence of cells was studied after binding of FITC-labelled WGA or U EA I as well as of FITC-marked pancreocymin/cholecystokinin (CCK-FITC) in a fluorescence microscope or FACScan. The strong binding of lectin s was inhibited by preabsorption with the specific sugars. In comparis on to the lectins the binding of CCK-FITC was low. There were two popu lations of acinar cells with different CCK-FITC binding capacity as de tected by flow cytometry. The CCK-FITC cell surface fluorescence was s ignificantly decreased by preincubation with unmarked hormone as well as with the nonlabelled lectins. The inhibition of CCK-FITC binding by lectins is discussed in respect to a possible competition of the lect ins and CCK for the CCK receptor.