Study of the Binding of Gold to Plasma Proteins

Abstract

The treatment of rheumatoid arthritis with gold salts such as sodium aurothiomalate (Myocrisin) is clinically well established. Because of their potential toxicity, however, it is desirable to understand as much as possible of the mechanism of action of the drugs and their transport in the blood. This thesis describes the characteristics of neutron activation analysis as a very sensitive method of analysis for studying the distribution of gold in blood during chrysotherapy. Electrophoresis was used to fractionate blood samples from twelve patients into the protein fractions and measurements were made to estimate the gold content of whole blood, plasma and serum and the gold bound to the prealbumin, albumin and α1 α2 ß, and γ-globulins, and to the blood cells. The results are summarised in tables. The tables show the concentration of ratios of the gold content of each plasma to serum, whole blood to plasma, and of blood cells to plasma, and that of total protein fractions to the serum, also shows the concentration ratios of gold content in each protein fraction to that of the total of the protein fractions. The results show there is little, if any, binding of gold to the fibrinogen, the majority of protein-bound gold is associated with the albumin fraction but that significant amounts are also bound to the other proteins. There is a small amount of gold bound to the blood cells except for three patients who show high gold levels. The ratio of the gold content of cathode and anode of the electrophoresis strip to that of the total protein fractions were measured to check if there was any gold loss, and it was found there is a small amount of such loss.