The synthesis and excretion of hippuric acid

Abstract

The rate of synthesis and excretion of hippuric acid in normal individuals and those with various renal disorder has already been studied by Kingsbury and Swanson 1 and this study made the basis of renal function test. In this work 2.4 grams of sodium benzoate was the dosage regardless of the size or weight of the individual. In the present paper the original work has been extended using dosages of sodium benzoate based on body weight in one series of 21 (50 milligrams per kilo) and on body surface in another series of 66 (1.8 grams per square meter of body surface). Body surfaces were obtained from the heightweight formula and chart of Dubois and Dubois. 2 The dosage based on surface was obtained by calculation after determining the body surface of one individual of average size and weight who had had 50 milligrams of benzoate per kilo of body weight. All individuals of both series were medical students who made the tests on themselves as part of their work in Physiolical Chemistry and whose urine specimens I made check analyses on by the method of Kingsbury and Swanson. 3 The benzoate was ingested quantitatively the first thing in the morning, having voided the night urine immediately before. Breakfast was omitted. The total water intake was 500 c.c. in every case. The urine was collected for the next three hours and immediately analyzed. The small and variable 3 hour normal output of hippuric acid independent of the ingested benzoate is included in these figures. Experience has shown that it is unnecessary to determine this and correct for it in the practical application of the test. In the first series of 21 it was noted that the groups of heavier individuals generally put out a smaller amount of hippuric acid per kilo of body weight than did the groups of lighter individuals, although all received the same dosage of sodium benzoate per kilo of body weight.