Turnover of adenosine in plasma of human and dog blood

Journal Article · Sat Apr 01 00:00:00 EST 1989 · Am. J. Physiol.; (United States)

OSTI ID:5990138

Moeser, G H.S.; Schrader, J; Deussen, A

To determine half-life and turnover of plasma adenosine, heparinized blood from healthy volunteers was incubated with radiolabeled adenosine in the physiological concentration range of 0.1-1 microM. Plasma levels of adenosine in vitro were 82 +/- 14 nM and were similar to those determined immediately after blood collection with a ''stopping solution.'' Dipyridamole (83 microM) and erythro-9(2-hydroxynon-3yl)-adenine (EHNA) (8 microM) did not measurably alter basal adenosine levels but completely blocked the uptake of added adenosine. Inhibition of ecto-5'-nucleotidase with 100 microM alpha, beta-methyleneadenosine 5'-diphosphate (AOPCP) reduced plasma adenosine to 22 +/- 6 nM. For the determination of adenosine turnover, the decrease in specific radioactivity of added (/sup 3/H)adenosine was measured using a dipyridamole-containing stopping solution. Without altering basal adenosine levels, the half-life was estimated to be 0.6 s. Similar experiments were carried out with washed erythrocytes or in the presence of AOPCP, yielding half-lives of 0.7 and 0.9 s, respectively. When the initial adenosine concentration was 1 microM, its specific activity decreased by only 11% within 5 s, whereas total plasma adenosine exponentially decreased with a half-life of 1.5 s. Venous plasma concentrations were measured after relief of a 3-min forearm ischemia. Changes in plasma adenosine did not correlate well with changes in blood flow but were augmented in the presence of dipyridamole.

• Research Organization: Universitaet Duesseldorf (Germany, F.R.)
• OSTI ID: 5990138
• Journal Information: Am. J. Physiol.; (United States), Vol. 256
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ADENOSINE
METABOLISM
ADENINES
ADP
AMP
BIOLOGICAL HALF-LIFE
BLOOD FLOW
BLOOD PLASMA
DOGS
MAN
NUCLEOTIDASES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VASODILATORS
AMINES
ANIMALS
ANTIMETABOLITES
AROMATICS
AZAARENES
BIOLOGICAL MATERIALS
BLOOD
BODY FLUIDS
CARDIOVASCULAR AGENTS
DRUGS
ENZYMES
ESTERASES
HETEROCYCLIC COMPOUNDS
HYDROLASES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MATERIALS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHATASES
PRIMATES
PURINES
RIBOSIDES
VERTEBRATES
550501* - Metabolism- Tracer Techniques