1962 Volume 8 Issue 2 Pages 99-114
Quantitative determination of thioctic acid was performed by microbioassay using Streptococcus faecalis 10 C1, in order to investigate the relation of thioctic acid metabolism to some skin diseases.
Studies were carried out on serum levels, the levels of the acid in 24-hour urine, the relation of diet to urinary thioctic acid, and the levels of the acid in the urine following injections of the acid. The results seemed to indicate that the best way to examine clinical metabolism of thioctic acid might be to determine its amount in the urine 2 hours after intravenous injections of 10mg of the acid and compare the results for patients with skin diseases with the controls.
When the urinary thioctic acid was measured 2 hours after injections in 40 healthy subjects, 20 to 30μg of the acid was excreted rather uniformly. From the results of this test as well as the findings on the urinary thioctic acid of the patients with serious skin diseases, 10 to 30μg of the acid in the urine 2 hours after injections seems to be in the normal range and the values below that level is considered abnormal. Those whose values are below 11μg can be regarded as relatively deficient in thioctic acid. We have, however, no intention of declaring these persons to be absolutely deficient in thioctic acid.
The results of loading tests showed that the values lower than 11μg were found in 47 cases (22%) out of 209 patients with skin diseases. As contrasted to 2 (5%) of 40 healthy subjects whose values were below 11μg, 19 (38.7%) of 49 patients with subacute eczema had values below 11μg. It is noteworthy that, when the numbers of the patients examined are taken into consideration, values below 11μg were found in fairly large proportions of the patients with contact dermatitis (17.3%), pigmentary anomaly such as leukoderma vulgaris (30.7%), chloasma (28.5%), and alopecia areata (26%). Though the total number of the patients examined was small, those with psoriasis and suppurative skin lesions had abnormal values.