Studies on the Metabolism of Coal-Tar Dyes (I)

Abstract

1. Through our research into the metabolism in rabbit of Naphthol Yellow S (NYS), it was clarified that NYS was excreted as the unchanged one without forming glucuronide or sulfate.2. About 10% and 50-70% of the amount of NYS administered to the test animals per os and through the subcutaneous injection respectively were excreted as unchanged NYS. In both cases most of them were found in the test animal's urine obtained within the first 24hrs. After the administration and scanty in the one within the second 24hrs. The concentration in the test animal's blood of NYS amounted to its highest level in 2hrs. after the administration per os and in 30min. after the subcutaneous method, then it decreased to the normal level of its concentration showed before the administrations. In the liver, kidney and other internal organs of the test animals which had completely discharged NYS no residue of deposited or remained NYS was discovered.3. We could measure the changes of the NYS concentration in the test animal's blood by means of the photoelectric colorimetry. Protein-excluding agents, measurable range, accuracy, etc. necessary for carrying out the colorimetrical procedure were investigated and thereby, basic important conditions for the measurement were established.4. In the sample urine obtained from the administered animals we could detect a red substance, presumably one of the metabolites, by the partition paper chromatography and isolate it by the column chromatography. But its properties are remained to be studied.