Fractional biological retention of intravenously injected 133Ba of high specific activity, was followed in adult rats for about 460 days. The specific activity of serum and of whole body were determined in serially-killed groups of rats. The data were used to test Marshall's theory of the metabolism of alkaline-earth elements. Observed values of retention were expressed as a power function of time, and monoexponential termination of retention was observed directly at a time exceeding by far the value predicted by the theory from observation of serum and body-specific activity. The integral of real retention between time=O and infinity was greater by a factor of ten than the value postulated by the theory. In the light of these observations some of the basic assumptions of the theory are questioned.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.