Vesicular Transmitter Content in Chromaffin Cells Can Be Regulated via Extracellular ATP

• The energy carrying molecule adenosine triphosphate (ATP) has been implicated for its role in modulation of chemical signaling for some time. Despite this, the precise effects and mechanisms of action of ATP on secretory cells are not well-known. Here, bovine chromaffin cells have been used as a model system to study the effects of extracellular ATP in combination with the catecholamine transmitter norepinephrine (NE). Both transmitter storage and exocytotic release were quantified using complementary amperometric techniques. Although incubation with NE alone did not cause any changes to either transmitter storage or release, coincubation with NE and ATP resulted in a significant increase that was concentration dependent. To probe the potential mechanisms of action, a slowly hydrolyzable version of ATP, ATP-gamma-S, was used either alone or together with NE. The result implicates two different behaviors of ATP acting on both the purinergic autoreceptors and as a source of the energy needed to load chromaffin cell vesicles.

Ämnesord

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Nyckelord

ATP

amperometry

intracellular vesicle impact cytometry

exocytosis

vesicle content

catecholamine uptake

quantal size

exocytosis

chromogranins

storage

vesicles

release

norepinephrine

accumulation

pharmacology

Biochemistry & Molecular Biology

Pharmacology & Pharmacy

Neurosciences

& Neurology

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