Characterization of the catecholamine uptake system in PC12

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6292445

Koide, M

The catecholamine uptake system of PC12 was characterized. PC12 cells took up both norepinephrine (NE) and dopamine (DA) from the external medium. Uptake of both substances had Na/sup +/-dependent and Na/sup +/-independent portions. The Na/sup +/-dependent portion followed Michaelis-Menten kinetics. For NE the K/sub m/ was 0.5 ..mu..M, and the V/sub max/ was 2.7 pmol min/sup -1/ (mg protein)/sup -1/. For DA the K/sub m/ was 0.2 ..mu..M and the V/sub max/ was 3.8 pmol min/sup -1/ (mg protein)/sup -1/. The uptake of both substances was inhibited by desmethylimipramine with an IC/sub 50/ of 0.01 ..mu..M and by benztropine with an IC/sub 50/ of 1 ..mu..M. These results suggest that NE and DA are transported by the same uptake system. Xylamine (N-2-chloroethyl-N-ethyl-2-methylbenzylamine) irreversibly inhibited the NE uptake (IC/sub 50/ = 15 ..mu..M). This inhibitions was Na/sup +/-dependent and was prevented by the coincubation of xylamine with cocaine or NE during the exposure of the cells to xylamine. These results indicate that xylamine must interact with the functioning NE uptake system to inhibit the uptake. PC12 accumulated (/sup 3/H)xylamine; this uptake had Na/sup +/-dependent and Na/sup +/-independent portions.

• Research Organization: California Univ., Los Angeles (USA)
• OSTI ID: 6292445
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
ALKALI METAL COMPOUNDS
AMINES
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
CARDIOTONICS
CARDIOVASCULAR AGENTS
CATECHOLAMINES
CHEMICAL COMPOSITION
DOPAMINE
DRUGS
HYDROXY COMPOUNDS
INHIBITION
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MEMBRANE TRANSPORT
NEUROREGULATORS
NORADRENALINE
ORGANIC COMPOUNDS
PHENOLS
POLYPHENOLS
SODIUM COMPOUNDS
SYMPATHOMIMETICS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
UPTAKE