Abstract
Pantothenic acid and its combined form, pantethine, in human urine were determined by microbioassay. The dose-response curve of pantethine on Lactobacillus bulgaricus B_1 showed steep slope between 2 to 10 μg/ml, but the sensitivity to pantothenic acid was one twenty-fifth of that to pantethine by this bacteria. On the other hand, the response of pantothenic acid to Lactobacillus fermenti ATCC 9338 was so specific that correct amount of pantethine was calculated from values of microbioassay using both Lactobacillus bulgaricus B_1 and Lactobacillus fermenti ATCC 9338. The urinary excretion of pantothenic acid in healthy subjects for 6 hours was 1,149 ± 91μg, whereas no pantethine was found in urine for same hours. The increase of urinary pantothenic acid was 21.3 ± 1.5% of dose following intramuscular administration of 20 mg of Ca-pantothenate. On the other hand, the increase of urinary pantethine was only 1.8 ± 0.8% of dose following intramuscu1ar administration of 20mg of pantethine. About 10% of dose of pantethine was found in urine as pantothenic acid. These data suggested that pantethine was more retained in blood or converted to coenzyme A in tissues compared with pantothenic acid.
