Biomaterial Database

Replacing 14C with stable isotopes in drug metabolism studies. 1996

F P Abramson, and Y Teffera, and J Kusmierz, and R C Steenwyk, and P G Pearson

Department of Pharmacology, George Washington University School of Medicine and Health Sciences, Washington, D.C. 20037, USA.

After administration of a mixed dose of both radioisotope and stable-isotope-labeled tirilazad, we carried out a parallel set of HPLC analyses for drug metabolites in bile samples from monkeys and dogs using either radioactivity monitoring (RAM) for 14C or the chemical reaction interface mass spectrometry technique (CRIMS) to detect 13C or 15N. CRIMS is a novel method where analytes are decomposed in a microwave-induced plasma and the elements contained in the analytes are reformulated into small gaseous species that are detected by a mass spectrometer. The comprehensiveness of detection, chromatographic resolution, sensitivity, signal/noise, and quantitative abilities of CRIMS were compared with RAM and in no case was RAM superior. This implies that stable isotopes may be substituted for radioisotopes in studies of drug metabolism where the ability of the latter approach to detect a label independent of the structures in which the label appears has been the primary reason for continuing to use a hazardous and expensive tracer. With HPLC-CRIMS, stable isotopes such as 13C and 15N can be comprehensively detected and quantitative patterns of drug metabolism from biological fluids can be produced that mirror the results when 14C is used.

UI	MeSH Term	Description	Entries
D008252	Macaca fascicularis	A species of the genus MACACA which typically lives near the coast in tidal creeks and mangrove swamps primarily on the islands of the Malay peninsula.	Burmese Long-Tailed Macaque,Crab-Eating Monkey,Cynomolgus Monkey,M. f. aurea,M. fascicularis,Macaca fascicularis aurea,Monkey, Crab-Eating,Monkey, Cynomolgus,Crab-Eating Macaque,Burmese Long Tailed Macaque,Crab Eating Macaque,Crab Eating Monkey,Crab-Eating Macaques,Crab-Eating Monkeys,Cynomolgus Monkeys,Long-Tailed Macaque, Burmese,Macaque, Burmese Long-Tailed,Macaque, Crab-Eating,Monkey, Crab Eating
D008297	Male		Males
D009587	Nitrogen Isotopes	Stable nitrogen atoms that have the same atomic number as the element nitrogen but differ in atomic weight. N-15 is a stable nitrogen isotope.	Nitrogen Isotope,Isotope, Nitrogen,Isotopes, Nitrogen
D011281	Pregnatrienes	Pregnane derivatives containing three double bonds in the ring structures.
D002247	Carbon Isotopes	Stable carbon atoms that have the same atomic number as the element carbon but differ in atomic weight. C-13 is a stable carbon isotope.	Carbon Isotope,Isotope, Carbon,Isotopes, Carbon
D002250	Carbon Radioisotopes	Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.	Radioisotopes, Carbon
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001646	Bile	An emulsifying agent produced in the LIVER and secreted into the DUODENUM. Its composition includes BILE ACIDS AND SALTS; CHOLESTEROL; and ELECTROLYTES. It aids DIGESTION of fats in the duodenum.	Biliary Sludge,Sludge, Biliary
D013058	Mass Spectrometry	An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.	Mass Spectroscopy,Spectrometry, Mass,Spectroscopy, Mass,Spectrum Analysis, Mass,Analysis, Mass Spectrum,Mass Spectrum Analysis,Analyses, Mass Spectrum,Mass Spectrum Analyses,Spectrum Analyses, Mass