The use of dispersed pancreatic islet cells in measurements of transmembrane transport

Abstract

Suspensions of dispersed islet cells were prepared by shaking collagenaseisolated pancreatic islets of ob ob - mice in Ca 2+-free buffer. The dispersed cells exhibited a glucose uptake with stereospecificity for the d isomer and concentrated Rb + about 30-fold from a medium containing 70 μ m RbCl. These results compare well with previous observations on unbroken islets and indicate that the dispersion procedure does not cause serious damage to the plasma membranes of the β-cells. By double isotope labeling and centrifuging the incubated cells through oil, incubation times as short as only a few seconds can be used. The elimination of the extracellular tissue space and the short incubation times should facilitate the study of transport kinetics in the pancreatic islet cells.