Aggregation and electrophoretic mobility studies on dissociated cells: II. Effects of ADP and ATP

Abstract

Both ADP and ATP markedly reduced the ability of cells from embryonic chick muscle to aggregate while rotated at 37 °C in a serum-free medium, pH 7.6. Pretreatment of the cells with ATP and ADP increased the surface charge density by 16% and 11%, respectively. The increased surface charge density persisted after thorough washing of the treated cells indicating binding of the charge-carrying nucleoside phosphates with the cell periphery. Available data do not support these changes in surface charge density as being responsible for the inhibitory effect of ATP and ADP on the embryonic chick muscle cells nor for the effects of these substances on other cell systems. A model based on the actomyosin concept of cell adhesion has been used to provide explanations for the inhibitory effect of ADP and ATP on the embryonic chick muscle cells and for the divers and opposite effects of these substances on other cell systems which have been similarly investigated.