Über Wirkungsbedingungen der Leber im Jodstoffwechsel

Abstract

The process investigated is the deiodination of diiodo-tyrosine. The reaction is studied by estimating the liberated iodine potentiometrically following deproteinization. It was found that the optimum of the reaction in liver slices is between pH 7.5 and 7.9. Extracts can be obtained by mincing the tissue and extracting with 2 parts 0.2.[image] phosphate buffer, pH 8. The activity of the extracts is always less than that of the intact tissue. It was also found that fine dispersal of the tissue resulted in loss of activity. Pre-incubation of the tissue for 20 hours led to a decrease in activity. Among various species examined, pig livers had the highest deiodination activity. This activity decreased rapidly after death.