Protection against X-irradiation by Sulphydryl Compounds

Abstract

The uptake of various SH compounds by mammalian cells has been studied in a number of experiments in which it was shown by means of ³⁵S-labelled cysteamine that the uptake depends on the conditions of incubation: increased concentration, pH and temperature led to an enhanced uptake. However, a quantitative correlation between extracellular SH concentration and intracellular SH content under various conditions could not be shown, because several factors made it impossible to determine exactly the actual uptake. One of these is the fact that compounds which have been taken up by the cells during the incubation period leak out of the cells during a washing procedure. Data obtained in experiments with ³⁵S-labelled cysteamine, cystamine, cysteine, thioglycol and glutathione showed that these compounds may not be taken up to the same extent by tissue culture cells.