Influence of zinc on iron uptake by monolayer cultures of rat hepatocytes and the hepatocellular ferritin.

Monolayer cultures of isolated rat hepatocytes on collagen gels were used to study the effect of zinc on (a) 59Fe uptake by the hepatocytes; (b) 59Fe uptake by the hepatocellular ferritin and (c) biosynthesis of ferritin and total proteins. While deposition of iron into the cellular ferritin was inhibited by zinc in a dose-dependent manner, iron uptake by the hepatocytes was inhibited significantly only at high concentrations of zinc. Biosynthesis of total proteins or ferritin was not affected by zinc. Since only a small fraction of the cellular 65Zn was found to be associated with ferritin, it was concluded that zinc was not deposited in ferritin. Intracellular distribution of 59Fe revealed that newly accumulated iron went into an iron pool the size of which could be increased by the presence of zinc.