Study of chromium speciation in normal and diabetic rats by activable enriched stable isotope technique

Chromium speciation was investigated in the liver cytosol, serum and urine of normal and diabetic rats after a single intravenous injection of enriche d stable isotope Cr-50 tracer solution. Sephadex G-25 gel chromatography co mbined with instrumental neutron activation analysis was used to isolate an d characterize protein-bound chromium in the above materials. The results i ndicate that Cr is mainly combined with a high-molecular-weight protein eit her in liver cytosol or serum. A low-molecular-weight, Cr-containing compou nd (LMWCr) was found in all the observed liver, serum and urine samples of both normal and diabetic rats. Chromium is excreted chiefly as LMWCr in uri ne.