Effect of Toxic Doses of L-Thyroxine on Tissue Water,Electrolytes and Plasma Protein in Rats

Abstract

Summary

1. Rats injected with L-thyrox-ine revealed an increased hematocrit and plasma water content. Concentrations of plasma Ca^{+ +}, Mg^{+ +}, glucose, total protein and erythrocyte glucose were reduced. No change was found in plasma levels of Na⁺ and K⁺ . 2. By fractionation of total plasma protein in the thyroxine-injected rats, reductions in alpha 1 and gamma globulins were observed. Concentrations of albumin, alpha 2 and β-globulins as well as A/G ratios were unaltered. 3. Weights of the ventricles of the heart were increased. Concentrations of cardiac Na⁺, K⁺ and total lipids were not changed. 4. Despite a dehydration of the muscle cells, a reduced concentration of in-tracellular K⁺ and an elevation of Na⁺, Cl^- and Ca⁺⁺ in the hyperthyroid state occurred. Muscle Mg^{+ +}, glycogen and total lipid levels were not modified. 5. The liver showed increased concentrations of water, Na⁺ and Mg⁺ which corresponded with a reduction of liver glycogen, K⁺ and Ca⁺⁺ contents. The liver total lipids remained unchanged.

The authors wish to acknowledge the assistance of Germaine Sproul, Elsie Pearson, Carolyn McTn-tyre, Judy Rutschman and Reba Wright throughout this study.