Evidence Hub

Effect of omega-conotoxin GVIA on release of 3H-gamma-aminobutyric acid from slices of rat neostriatum

Thate A, Meyer DK

Naunyn-Schmiedeberg's archives of pharmacology, 1989

Abstract

omega-Conotoxin GVIA (omega-CT) diminished the potassium-induced in vitro release of 3H-gamma-aminobutyric acid (3H-GABA) from slices of rat neostriatum in a manner which depended on the concentration of potassium. omega-CT (0.1 mmol/l) decreased the release of 3H-GABA induced by 25 mmol/l K+ from 11.6% to 6.1% of tissue content, ie. by 48%, while it did not affect the release of 3H-GABA caused by 20 mmol/l K+, which was 4.8% of tissue content. However, in the presence of a polyclonal antiserum or cysteamine (600 mumol/l), both of which diminish the effects of endogenous somatostatin, 0.1-10 nmol/l omega-CT decreased the release of 3H-GABA induced by 20 mmoles/l K+ by 40%. It is concluded that omega-CT did not only inhibit GABA-neurones, but had an additional inhibitory effect on somatostatin neurones which are known to depress the release of 3H-GABA. It is further concluded that neuronal interactions, which are possible in brain slice preparations, may impede the interpretation of effects of drugs, especially if agents are used which affect basic mechanisms of transmitter release and thus the release of various transmitters from neurones.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free