SINGLE PULSE STIMULATION OF GUINEA‐PIG VAS DEFERENS AND THE PRESYNAPTIC RECEPTOR HYPOTHESIS

1 The effect of phenoxybenzamine on the efflux of [3H]‐noradrenaline and the mechanical response to single pulse excitation of superfused guinea‐pig vas deferens was determined to examine the validity of the currently accepted hypothesis of a presynaptic negative feedback system on adrenergic nerve...

Full description

Saved in:
Bibliographic Details
Published in:British journal of pharmacology 1979-06, Vol.66 (2), p.343-349
Main Author: KALSNER, STANLEY
Format: Article
Language:English
Subjects:
Animals
Cocaine - pharmacology
Electric Stimulation
Guinea Pigs
Hydrocortisone - pharmacology
Male
Norepinephrine - metabolism
Phenoxybenzamine - pharmacology
Vas Deferens - drug effects
Vas Deferens - physiology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:1 The effect of phenoxybenzamine on the efflux of [3H]‐noradrenaline and the mechanical response to single pulse excitation of superfused guinea‐pig vas deferens was determined to examine the validity of the currently accepted hypothesis of a presynaptic negative feedback system on adrenergic nerve terminals. 2 The adrenoceptor antagonist enhanced both the outflow of tritium and the mechanical response to single pulse stimulation. The efflux of labelled material and the responses to 4 pulses were also enhanced, as expected. 3 Blockade of neuronal and extraneuronal uptake did not by itself increase nerve‐induced outflow or the mechanical response nor did it prevent phenoxybenzamine from doing so. 4 The present observations cannot be accommodated within the framework of a hypothesis that proposes that the enhancement of response and tritium efflux by phenoxybenzamine results from blockade of a feedback system whereby noradrenaline released by previous impulses inhibits its own subsequent release.
ISSN:0007-1188
1476-5381
DOI:10.1111/j.1476-5381.1979.tb13686.x