Abstract
The conventional determination methods for pantothenic acid and CoA were examined and some amendment points were discussed. By using these modified determination methods the changes in blood pantothenic acid level of children and in pantothenic acid and CoA contents of rat tissues according to growth were analysed. In comparing with CoA contents determined by sulfanylamide acetylation method and sorbyl-CoA formation method, it was presumed that rat liver contained a relatively large amount of phosphopantetheine and dephospho-CoA besides CoA as a bound pantothenic acid. In order to confirm this point the in vitro biosynthesis of CoA from phosphopantetheine or decomposition of phosphopantetheine from CoA was investigated. The existance of phosphopantetheine and dephospho-CoA in rat liver as a bound pantothenic acid was confirmed from these observations. The amount of this intermediate between pantothenic acid and CoA in rat liver was definitely influenced by pantothenic acid content in diet, adrenalectomy and administration of glucocorticoid, antibiotics, anticancer drugs or large doses of thiamine derivatives. Then, this intermediate was accurately identified as phosphopantetheine after isolation and confirmation by colum- and paper-chromatographies. The amount of phosphopantetheine that was determined by both above mentioned indirect and direct methods was quite equal. It was recognized that this phosphopantetheine was not produced by the decomposition of CoA in rat liver during preparation of samples with treatment of hot water extraction. The relation between this intermediate and acyl carrier protein found in Escherichia coli or fatty acid synthetic multi-enzyme complex were observed in order to clarify the biological meaning of phosphopantetheine in rat liver.
