Comparison of Ammonium Sulfate Fractionation of Proteins and of Protein-Bound Mercury in Kidney Soluble Fraction of Chow-Fed and Sucrose-Fed Rats

¹ From the Department of Physiology, Washington University School of Medicine, St. Louis, Missouri

Most rats fed on sucrose and vitamins for 3 weeks or more survive intravenous injection of mercuric chloride (3 mg/kg), which is uniformly lethal for normal rats. With this increased mercury tolerance a higher percentage of the total kidney mercury is found in the soluble fraction of kidney homogenate. In an attempt to demonstrate qualitative differences in the soluble fraction proteins of sucrose-fed rats as compared with normal, salting-out curves by ammonium sulfate fractionation were obtained. No change in the protein salting-out curves was seen on sucrose feeding, but a shift in protein-bound mercury to the ‘albumin-like’ proteins was observed. The excess soluble fraction mercury of sucrose-fed rats is found in the ‘albumin-like’ proteins. Serial slicing of the kidney showed the mercury largely in the cortex in both types of rat.