Ionic mechanisms involved in the release of /sup 3/H-norepinephrine from the cat superior cervical ganglion

Journal Article · Sun Feb 26 23:00:00 EST 1984 · Life Sci.; (United States)

DOI:https://doi.org/10.1016/0024-3205(84)90203-0· OSTI ID:6047489

Alder-Graschinsky, E; Filinger, E J; Martinez, A E

It has previously been reported that in the isolated cat superior cervical ganglion (SCG) labeled with tritiated norepinephrine (/sup 3/H-NE), the stimulation of the preganglionic trunk at 10 Hz as well as the exposure to 100 ..mu..M exogenous acetylcholine (ACh), produced a Ca/sup + +/-dependent release of /sup 3/H-NE. The present results show that a Ca/sup + +/-dependent release of /sup 3/H-NE was produced also by exposure to either 50 ..mu..M veratridine or 60 mM KCl. Tetrodotoxin (0.5 ..mu..M) abolished the release of /sup 3/H-NE induced by preganglionic stimulation, ACh and veratridine but did not modify the release evoked by KCl. The metabolic distribution of the radioactivity released by the different depolarizing stimuli showed that the /sup 3/H-NE was collected mainly unmetabolized. In the cat SCG neither the release of /sup 3/H-NE evoked by KCl nor the endogenous content of NE was modified by pretreatment with 6-OH-dopamine (6-OH-DA). On the other hand, this chemical sympathectomy depleted the endogenous content of NE in the cat nictitating membrane, whose nerve terminals arise from the SCG. The data presented suggest that the depolarization-coupled release of NE from the cat SCG involves structures that are different to nerve terminals and that contain Na/sup +/ channels as well as Ca/sup + +/.

• Research Organization: Instituto de Investigaciones Farmacologicas, Buenos Aires, Argentina
• OSTI ID: 6047489
• Journal Information: Life Sci.; (United States), Journal Name: Life Sci.; (United States) Vol. 34:9; ISSN LIFSA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ALKALINE EARTH METALS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMICAL REACTION KINETICS
CALCIUM
CATS
CHLORIDES
CHLORINE COMPOUNDS
DEPOLARIZATION
DRUGS
ELEMENTS
GANGLIONS
HALIDES
HALOGEN COMPOUNDS
IONIC COMPOSITION
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MAMMALS
METALS
NERVOUS SYSTEM
POTASSIUM CHLORIDES
POTASSIUM COMPOUNDS
RADIOASSAY
REACTION KINETICS
RESPONSE MODIFYING FACTORS
SYMPATHOMIMETICS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES