EFFECTS OF DICHLOROISOPROTERENOL ON MACROMOLECULAR-SYNTHESIS AND DIFFERENTIATION IN TETRAHYMENA-VORAX

The effect of dichloroisoproterenol on macrostomal cell formation in T etrahymena vorax was examined and the drug was found to be 50% inhibit ory at a concentration of 88 mu M. Cellular uptake and incorporation o f a variety of radiolabelled precursors was monitored in the presence of dichloroisoproterenol. The results demonstrate a strong, concentrat ion-dependent inhibitory effect on RNA and protein biosynthesis, with a lesser inhibition observed for lipid biosynthesis. These data indica te that dichloroisoproterenol's reported effects on vacuole formation and processing in Tetrahymena are nonspecific with regard to phagocyti c processes, but result from a general suppression of macromolecular s ynthesis.