title: Endogenous levels of beta-carotene in human buccal mucosa cells by reversed-phase high-performance liquid chromatography.
abstract: We have developed a reversed-phase high-performance liquid chromatographic assay for the measurement of low nanogram levels of beta-carotene in a single sample of human buccal mucosa cells. The method includes a simple sonification step for cell disruption and release of the compounds into the supernatant. The limits of detection were 0.02, 0.02 and 0.07 ng/mg of protein for beta-carotene, retinol and retinol palmitate, respectively. Two patient populations were analysed. Average endogenous levels for beta-carotene normalized to protein were 0.25 ng/mg of protein (range 0.04-1.9 ng/mg, twelve patients). No evidence of endogenous retinol or retinol palmitate could be detected in the human samples. An oral dosing study of four normal individuals showed a wide variation of beta-carotene uptake. This rapid and sensitive method will enable investigators to use the non-invasive technique of buccal mucosa cell harvesting to determine cellular depot levels of beta-carotene in various patient populations.
authors.affiliation: Department of Pharmacology, College of Medicine, University of Arizona, Tucson 85721.
authors.forename: S A
authors.initials: SA
authors.lastname: Newcomb
authors.forename: A J
authors.initials: AJ
authors.lastname: Culling-Berglund
authors.forename: T P
authors.initials: TP
authors.lastname: Davis
mesh_terms: D000284:Administration, Oral; D002338:Carotenoids / Q000008:administration & dosage / Q000032:analysis* / Q000493:pharmacokinetics; D002610:Cheek; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004224:Diterpenes; D005260:Female; D006801:Humans; D008297:Male; D009061:Mouth Mucosa / Q000032:analysis / Q000166:cytology*; D000084562:Retinyl Esters; D014801:Vitamin A / Q000031:analogs & derivatives / Q000032:analysis
chemical_list: D004224:Diterpenes; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate; D002338:Carotenoids