Effects of XXXX and @entity4878 on intercellular junctional communication measured with a @entity7792 incorporation assay.

@entity7792 @entity1 @entity4878 @entity318 @entity20773 @entity33182 @entity5 @entity865 @entity864 @entity1968
Inhibition of intercellular junctional communication by @entity864 ( @entity865 ) and @entity4878 was investigated using a @entity7792 incorporation assay. This new assay uses metabolic co-operation between @entity33182 -deficient @entity1 fibroblasts and arginosuccinate synthetase-deficient cells as a measure of junctional communication. Short-term exposure to @entity865 resulted in virtually complete inhibition of metabolic co-operation when V79 cells were used as the synthetase-deficient type. When synthetase-deficient @entity1 fibroblasts were used, inhibition by @entity865 was only partial. Exposure to high concentrations of @entity865 for prolonged periods resulted in partial reversal of communication inhibition and a refractory state in which cells were unresponsive to @entity865 . @entity1968 and other @entity4878 also inhibited metabolic co-operation, but did not cause desensitisation of the type seen with @entity865 after prolonged exposure. Cultures which had been made refractory to @entity865 remained sensitive to inhibition by @entity1968 and @entity318 , indicating that these latter compounds inhibit junctional communication by a mechanism different from @entity865 . Simultaneous exposure of cultures to @entity865 and @entity1968 showed that the inhibitory effects on metabolic co-operation of these compounds were additive. @entity20773 did not antagonise the effect of @entity865 . These results suggest that @entity1968 and @entity20773 exert their anti- @entity5 -promoting action by mechanisms which are not mediated by intercellular junctional communication.
