Determination of the rate of urea synthesis from serial measurements of plasma urea concentration after an alanine load: theoretical and methodological aspects.

A method is described by which the rate of synthesis of urea can be calculated from the change of plasma concentration of urea after an alanine load. The results can be expressed in terms of f, the maximum increase in the rate of urea synthesis, and t, the time at which urea synthesis reaches its maximum. These parameters are calculated by an algebraic curve-fitting technique which is suitable for a desk computer. The method removes the need for isotopic analysis and urine collections. The effect of various errors and experimental conditions on the calculated synthesis parameters is investigated.