The aminopyrine breath test as a measure of liver function: a quantitative description of its metabolic basis in normal subjects

Journal Article · Wed Sep 01 00:00:00 EDT 1982 · J. Lab. Clin. Med.; (United States)

OSTI ID:6565130

Irving, C S ^[1]; Schoeller, D A; Nakamura, K I; Baker, A L; Klein, P D

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1. Baylor Coll. of Medicine, Houston, TX

A dual-isotope kinetic study of aminopyrine disposition and metabolism has been carried out on five normal adult subjects. Oral administration of /sup 13/C-aminopyrine (2 mg/kg) accompanied by simultaneous intravenous injection of /sup 14/C-aminopyrine was followed by serial measurements of aminopyrine and monomethylaminopyrine in plasma and urine over 6 hr. Timed collections of respiratory CO/sub 2/ were analyzed for the content of excess /sup 13/CO/sub 2/ and for /sup 14/CO/sub 2/. On separate days, an intravenous bolus of /sup 13/C-labeled NaHCO/sub 3/ was administered to obtain estimates of the kinetic parameters of CO/sub 2/ elimination in each subject. These data were fitted simultaneously to a multicompartmental model that, in addition to providing hitherto unavailable quantitative information, has revealed that (1) demethylation is the major elimination pathway for aminopyrine; (2) a major alternative pathway not involving demethylation exists for monomethylaminopyrine; and (3) only 50% of the labeled carbon generated by demethylation eventually is oxidized to HCO/sup 3 -/. The sensitivity of seven types of APBT scores to 50% reductions in the rates of aminopyrine absorption, metabolism of monomethylaminoantipyrine, intermediate carbon metabolism, and bicarbonate kinetics was evaluated with breath test curves simulated using the APBT model. Every APBT score currently in use was affected by variations in both gastrointestinal output of aminopyrine and bicarbonate kinetics. There is a need for further development of selective scoring methods in the aminopyrine breath test. (JMT)

• OSTI ID: 6565130
• Journal Information: J. Lab. Clin. Med.; (United States), Journal Name: J. Lab. Clin. Med.; (United States) Vol. 100:3; ISSN JLCMA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AZOLES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL FUNCTIONS
BIOLOGICAL MATERIALS
BIOLOGICAL MODELS
BIOLOGICAL WASTES
BLOOD
BLOOD PLASMA
BODY
BODY FLUIDS
BREATH
CARBON 13
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON ISOTOPES
CARBON OXIDES
CHALCOGENIDES
DIAGNOSTIC USES
DIGESTIVE SYSTEM
DRUGS
EVEN-ODD NUCLEI
FUNCTIONS
GLANDS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LIGHT NUCLEI
LIVER
MATERIALS
METABOLISM
NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
PATIENTS
PYRAZOLES
REACTION KINETICS
STABLE ISOTOPES
TRACER TECHNIQUES
URINE
USES
WASTES