The sugars of urine

Abstract

HARDING AND SELBY [1931] have recently published extensive observations on the output of fermentable sugar in normal urine. Their report prompts us to record some findings made in this laboratory during recent years. Our plan has been to study the daily excretion of both fermentable and nonfermentable sugar by normal individuals and with these data for comparison to investigate various factors which influence the excretion.As will be noted from the introduction of the paper by Harding and Selby the question of a suitable method of analysis is paramount in an investigation of this kind. This is especially true when determination of non-fermentable as well as fermentable sugar is involved. Here the efficient pre-treatment of the urine to remove non-sugar reducing substances is imperative. Precipitation with mercuric nitrate-sodium bicarbonate according to Benedict and Osterberg [1918] is probably the most efficient treatment which has been reported in the past, yet this method has the disadvantage of leaving a high salt concentration in the filtrate and there is danger of adding too much bicarbonate with resulting oxidation of sugar by the mercuric ion. Treatment with Lloyd's reagent which was introduced by Folin and Berglund [1922] and which has been used in various ways by different workers, according to our experience, leaves much non-sugar reducing material. In order that maximum accuracy be obtained it is also advisable to use a sugar method capable of estimating small quantities.Preliminary to their studies, the writers have developed a procedure of analysis for fermentable and non-fermentable sugar in urine which seems to them to represent an improvement over former methods. It is based upon three procedures. Filtrates of urine are prepared by the HgSO4-BaCO3 technique of West, Scharles and Peterson [1929] which has been found effective in removing interfering nitrogenous substances from biological fluids without introducing appreciable amounts of electrolytes and without loss of sugar.

The determination of inositol in animal tissues

“…From a burette are then added slowly with shaking 30 ml. of the acid-mercuric sulphate reagent [West and Peterson, 1932] prepared by dissolving 27 g. of mercuric sulphate in 100 ml. of 10 % (by weight) sulphuric acid at 50 and separating the solution from the slight precipitate which forms as room temperature is reached.…”

“…The procedure was recommended by the authors for the preparation of filtrates from hydrolysed tissues. The reagent was subsequently modified slightly when applied to urine [West and Peterson, 1932].. On the basis of these considerations it was decided to compare the extent to which the alkaline iodomercurate reagent was reduced by filtrates prepared from identical tissue extracts by means of the West et al mercuric sulphate method, phosphotungstic acid in sulphuric acid, normal lead acetate and mercuric chloride [Johnson, 1887].…”