title: Ascorbic acid and in situ kinetics: a new approach to vitamin requirements.
abstract: Ascorbic acid requirements are based on preventing the deficiency disease scurvy and on urinary excretion of vitamin C. We proposed the first quantitative approach to determining optimal requirements for ascorbic acid and other vitamins, called in situ kinetics. In situ kinetics biochemically is based on the application of Michaelis-Menten reaction kinetics to ascorbic acid-dependent reactions in situ. Clinically in situ kinetics is based on determining vitamin availability to tissues so that cell-specific reactions can occur. The biochemical concepts of in situ kinetics are verified for the first time through studying ascorbic acid regulation of norepinephrine biosynthesis. The principles of in situ kinetics can now be applied to humans and human cells and for determining optimal requirements for ascorbic acid and for other vitamins.
authors.affiliation: Laboratory of Cell Biology and Genetics, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892.
authors.forename: M
authors.initials: M
authors.lastname: Levine
authors.forename: K R
authors.initials: KR
authors.lastname: Dhariwal
authors.forename: P W
authors.initials: PW
authors.lastname: Washko
authors.forename: J D
authors.initials: JD
authors.lastname: Butler
authors.forename: R W
authors.initials: RW
authors.lastname: Welch
authors.forename: Y H
authors.initials: YH
authors.lastname: Wang
authors.forename: P
authors.initials: P
authors.lastname: Bergsten
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology; D002837:Chromaffin Granules / Q000378:metabolism; D002838:Chromaffin System / Q000166:cytology / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004579:Electron Transport; D006801:Humans; D007700:Kinetics; D009638:Norepinephrine / Q000096:biosynthesis; D009751:Nutritional Requirements; D014815:Vitamins
chemical_list: D014815:Vitamins; D001205:Ascorbic Acid; D009638:Norepinephrine