Cultured human skin fibroblasts absorb 65Zn. Optimization of the method and study of the mechanisms involved.

The radioactive isotope 65Zn was used to study the incorporation of zinc by cultured human skin fibroblasts. The development of the method for studying cell uptake of 65Zn in a minimal synthetic medium is presented. Kinetics carried out on control cultures up to 240 min indicated that zinc uptake occurred in three phases, the first being the most rapid. Temperature and pH affect zinc uptake, in favor of an active transport process. In addition, the rate of incorporation is considerably decreased during the first phases after adding potassium cyanide, during the last phases after adding sodium iodoacetate, and during all the phases if dithioerythritol is used. A hypothesis is therefore proposed according to which several types of mechanisms would be involved in zinc uptake by fibroblasts. At least a part of these mechanisms is energy-dependent.