On the origin of glycocoll in the animal body

Abstract

The various forms of protein, with the exception of casein and gelatin, contain about four per cent. of their N in the form of preformed glycocoll N. On giving benzoic acid or its salts to animals, they have the power of detoxicating it by combining it with glycocoll and forming hippuric acid.

About eleven years ago, Parker and Lusk employed this fact in an attempt to determine the maximum amount of hippuric acid that rabbits can produce. They studied the relationship between the total N in the urine and the glycocoll N eliminated as hippuric acid, HN/N. They found that for every 100 grams of total N excreted in the urine, an average of about 4 grams of N was eliminated in the glycocoll radical of the hippuric acid. After administering the first large dose of lithium benzoate to the animals, they invariably obtained a much higher HN/N ratio, 9.01 per cent. in experiment III., 7.14 per cent. in experiment IV., and 7.87 per cent. in experiment VI. They regarded this as a “sweeping out” of surplus glycocoll.

Since then, Wiechowski and Magnus-Levy have studied the same problem. Wiechowski obtained HN/N ratios of 45.4, 55, 50 and in one case, even as much as 64 per cent. Magnus-Levy found in his rabbits a maximum ratio of 25 and 28 per cent., in his sheep 27.8 per cent.

To investigate the cause of these discrepancies, Professor Lusk kindly suggested that I continue the study of this problem.