1982 Articles

INSULIN ENDOCYTOSIS IS HIGHLY CORRELATED WITH INSULIN REQUIREMENT FOR GROWTH*

Murphy, Robert F.; Powers, Scott; Cantor, Charles R.; Pollack, Robert

In the past few years many of the steps involved in receptor-mediated endocytosis have been clarified using video intensification microscopy to follow the binding, clustering, internalization and subsequent processing of fluorescently labeled hormones.' Flow cytometry is a recently developed technique which, like video intensification microscopy, measures the properties of individual cells, and can accurately quantitate these properties for large numbers of cells. We have recently used flow cytometry to measure the binding and internalization by Swiss 3T3 cells of a fluorescein isothiocyanate (FITC) derivative of insulin.2 We now describe the changes in insulin internalization that accompany the loss of growth control after transformation by SV40.