Note 62 — Chapter XXX · MEDICINAL AND OTHER MODES OF THERAPY (continued)—CHRONIC ARTICULAR GOUT AND ASSOCIATED MORBID CONDITIONS

Sir Archibald Garrod has suggested that guaiacum has a distinct effect in reducing the amount of uric acid excreted, i.e., it was thought that the uric acid is eliminated in some other form, possibly hippuric acid. Accordingly Martindale and Westcott conducted investigations to determine whether this resin increases or decreases the elimination of uric acid from the human body.

A normal individual took guaiacum resin in 5-grain doses daily in the morning, and the uric acid was estimated in the urine the same afternoon. Hippuric acid was also estimated in specimens of the same urine by the method given by Allen, “Chemistry of Urine,” p. 186. After a day’s interval the acids were estimated on several days without administration of the drug. The two series were then repeated on the same lines after an interval. Seeing that the diet of the individual could not well be controlled in weighed amounts of food, as would strictly be necessary for an investigation of this kind, it was thought that to express the results in percentage ratios of uric acid to excess of solids (R.U.A.) over water might yield more comparable results.

Joulie employs this method of indicating the constituents of urine by ratios; cf. Vol. I., p. 736. Thus, taking a specimen of urine with the following “normal” factors in grams per litre:—

Specific gravity 1017·8

Excess of solids over water 17·8

Physiological acidity in terms of H₂SO₄ 0·849

Total P₂O₄ 2·083

Cl 6·865

Urea 18·75

Uric acid 0·416

Hippuric acid 1·3

(mean).

One may express the constituents as the following percentage ratios:—

Normal.

“R.A.”—Ratio of physiological acidity to excess of solids over water 4·77 0·849 × 100 17·8

“R.P.”—Ratio of total P₂O₄ to excess of solids over water 11·17

“R.U.”—Ratio of urea to excess of solids over water 100·53

“R.U.A.”—Ratio of uric acid to excess of solids over water 2·33

“R.H.A.”—Ratio of hippuric acid to excess of solids over water 7·3

“R.P./R.A.”—Ratio of phosphoric acid to ratio of acidity (Joulie’s factor, cf. Vol. I., p. 737) 2·45

Ratio of uric acid, for example, is arrived at thus 0·416 × 100 17·8 = 2·33

The results which we obtained are given in the following table:—

Effects of Guaiacum Resin on the Urine of a Normal Individual.

Date. Sp. Gr. Urea. Uric Acid. Hippuric Acid. “R.U.A.” “R.H.A.”

With guaiacum 28/12/11 1·0107 2·29 0·09 0·09 4·43 4·34

With guaiacum 29/12/11 1·0247 1·29 0·08 0·1 3·34 4·04

With guaiacum 1/1/12 1·0215 2·56 0·015 0·15 4·88 6·97

With guaiacum 2/1/12 1·0141 2·82 0·10 0·2 4·2 8·20

Without guaiacum 4/1/12 1·0229 2·42 0·06 0·1 2·62 4·36

Without guaiacum 5/1/12 1·0249 2·42 0·08 0·2 3·16 8·03

Without guaiacum 8/1/12 1·0255 3·09 0·10 0·225 4·11 8·12

With guaiacum 11/1/12 1·0233 2·56 0·09 0·1 3·7 4·29

With guaiacum 12/1/12 1·0213 1·88 0·075 0·1 3·05 4·69

Without guaiacum 24/1/12 1·0239 2·42 0·08 0·038 3·45 1·57

Without guaiacum 25/1/12 1·0229 2·15 0·06 0·05 2·61 2·18

Average uric acid ratio under guaiacum resin = 3·39

Average uric acid ratio without guaiacum resin = 3·19

Average hippuric acid ratio under guaiacum resin = 5·43

Average hippuric acid ratio without guaiacum resin = 4·49

The quantity of hippuric acid normally found is known to vary enormously, e.g., between 0·02 and 0·25 per cent. From this we deduced, for purpose of this investigation, a mean normal R.H.A. of 7·3. A number of other investigations were conducted on analogous lines, but need not be recorded.

From the results of these experiments one notices an average increase of uric and hippuric acids during the “+ guaiacum” periods. It is not possible to draw a conclusion without further corroboration. The amount of each acid from day to day is seen to be erratic, and the process of estimation of hippuric acid is not accurate.