[Receptor-mediated endocytosis of alpha 2-macroglobulin in living intact 3T3 cells]

Internalization process of the fluoresceinisothiocyanate-labeled alpha 2-macroglobulin (MG-F) in Swiss 3T3 cells has been studied. The presence of internalized MG-F, formation of endocytotic vesicles and endosomal pH value were estimated visually on living monolayer cells with TV microscope, on the base of supervidicon LI-702. The use of the TV method allowed to obtain a series of photographs of cell images without any significant dye fading. A brief characteristics of microprocess control system is presented. The influence of various chemical agents on MG-F internalization and endosomal pH value was investigated. It was shown that dansylcadaverine (150-200 microM) and monensin (10-20 microM) inhibited MG-F internalization. Methylamine, chloroquine and monensin quickly enhanced the endosomal pH value, while other amines did not, for example dansylcadaverine.