title: A practical assay of lipoate in biologic fluids and liver in health and disease.
abstract: A procedure for assaying lipoic acid concentration in biologic fluids and tissues was devised using a eukaryotic protozoan Tetrahymena thermophila. T.thermophila has a specific and sensitive (30 pg/ml) requirement for lipoic acid. Unlike humans and other microorganisms, T.thermophila can not synthesize lipoic acid; hence, its requirement for exogenous lipoic acid is specific. The lipoic acid supplied to T. thermophila by the processing of biologic fluids and tissues during the assay procedure, permits the derivation of a practical assay for lipoate concentration as described here. Lipoate concentration in biologic fluids and tissue obtained from healthy humans, compared to those obtained from patients with renal and liver disease, indicate deviations from normal during disease. Absorption chartings of 200 mg of DL-alpha-lipoic acid in humans indicate a peak concentration of lipoate in plasma 2 h after ingestion and then a steady descent of lipoate to a baseline level after 24 h. With this practical assay, it is now possible to chart lipoate's antioxidant activity and therapeutic action during health and disease.
authors.affiliation: Department of Preventive Medicine and Community Health, University of Medicine & Dentistry of New Jersey, New Jersey Medical School, Newark 07107, USA.
authors.forename: H
authors.initials: H
authors.lastname: Baker
authors.forename: B
authors.initials: B
authors.lastname: Deangelis
authors.forename: E R
authors.initials: ER
authors.lastname: Baker
authors.forename: S H
authors.initials: SH
authors.lastname: Hutner
mesh_terms: D000042:Absorption; D000328:Adult; D000818:Animals; D001681:Biological Assay; D001826:Body Fluids / Q000737:chemistry*; D006801:Humans; D007674:Kidney Diseases / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000737:chemistry*; D008107:Liver Diseases / Q000378:metabolism*; D008875:Middle Aged; D012016:Reference Values; D016808:Tetrahymena thermophila / Q000187:drug effects / Q000254:growth & development; D008063:Thioctic Acid / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics
chemical_list: D008063:Thioctic Acid