The formation of sulphate from cysteine and methionine by tissues in vitro

IN spite of the very large amount of work that has been done on the variations in the rate of excretion of sulphate by animals and men after the administration of various sulphur compounds, it seems that no one has shown that either an organ or a tissue preparation can make sulphate from an unoxidised sulphur compound in vitro. Rothera [1905] could find no sulphate when he incubated cystine with liver mince or when he perfused the liver with cystine, and it seems probable that several other workers have been similarly unsuccessful. The forma- tion of sulphate from sulphuric esters by minced mammalian organs has been studied by Neuberg and Simon [1925], but this process, although perhaps connected with the type of oxidation which forms the subject of this paper, is obviously relatively simple.