Characterization of norepinephrine accumulation by a crude synaptosomal-mitochondrial fraction isolated from rat heart.
Life Sci
; 48(13): 1317-24, 1991.
Article
in En
| MEDLINE
| ID: mdl-1848347
Norepinephrine (NE) uptake into a heart synaptosomal-mitochondrial fraction was assessed under conditions where neuronal uptake (type 1) was linear with respect to both time and protein concentration. The NE accumulation process was sensitive to incubation temperature, sodium ion concentration and medium osmolality. Furthermore, NE uptake was attenuated by the neuronal uptake inhibitor desmethylimipramine (DMI) in a concentration dependent manner; the IC50 value was approximately 10 nM and maximum inhibition was obtained at 100 nM. In contrast, the extraneuronal uptake inhibitor, metanephrine did not significantly attenuate NE uptake. Kinetic analysis demonstrated that the DMI sensitive NE accumulation is saturable with a KM of approximately 400 nM and that NE uptake occurs via a single uptake process. This demonstration of neuronal type NE uptake by a synaptosomal-mitochondrial fraction constitutes a successful demonstration of the preparation of a rat heart subcellular fraction containing functional synaptosomes.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Synaptosomes
/
Norepinephrine
/
Mitochondria, Heart
/
Myocardium
Limits:
Animals
Language:
En
Journal:
Life Sci
Year:
1991
Document type:
Article
Country of publication:
Países Bajos