Issues in Constant Tracer Infusion and Mineral Metabolism

Abstract

Determining metabolic kinetics may, at first, seem to require considerable work without yielding anything more than a better understanding of some fundamentals. This paper argues that such measurements are virtually the sine qua non of understanding many otherwise perplexing clinical situations. For example, if a pregnant woman is hypocalciuric, and at risk for pre-eclampsia, is the hypocalciuria a consequence of kidney failure, a failure to absorb sufficient dietary calcium or something entirely unsuspected? If an individual is hypercortisolenemic, is that a consequence of a decreased clearance rate or of an increased production of endogenous cortisol? Such questions can be answered only through studies of the dynamics of the systems and by the measurement of rate processes for absorption, production, etc.