Possible Role of Transplasma Membrane Ferricyanide Reductase in Mitogenic Activation of Rat Liver Cells

Transplasma ferricyanide reductase of hepatocytes is activated by the specific mitogen, r-LGF, immediately upon addition, in a sodium-dependent, amiloride-sensitive way. The above phenomenon seems to be transient, and is abolished when the sodium gradient is reversed. Ferricyanide activates H+ efflux and 22Na uptake in parallel fashion. Ferricyanide by itself increases 22Na uptake and H+ efflux, and the natural substrate for the redox enzyme, diferric transferrin, increases DNA synthesis when added, together with submaximal doses of r-LGF, to cultured hepatocytes.