UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

[alpha]1-adrenoceptor subtypes in the rat isolated epididymal vas deferens, spleen and human prostate and their signal transduction mechanisms

Burt, Richard Paul; (1996) [alpha]1-adrenoceptor subtypes in the rat isolated epididymal vas deferens, spleen and human prostate and their signal transduction mechanisms. Doctoral thesis (Ph.D), UCL (University College London). Green open access

[thumbnail of [alpha]1-adrenoceptor_subtypes.pdf] Text
[alpha]1-adrenoceptor_subtypes.pdf

Download (6MB)

Abstract

The aims of this investigation were (1) to functionally characterize the [alpha]1-adrenoceptor mediating contractions of the rat isolated epididymal vas deferens, spleen and human prostate using [alpha]1-adrenoceptor subtype selective antagonists, and (2) to study the possible mechanisms of contraction to [alpha]1-adrenoceptor stimulation in these tissues. Contractions mediated by [alpha]1-adrenoceptors in the rat epididymal vas deferens and human prostate were antagonized by subtype selective competitive antagonists with pA2 values consistent with their affinities in binding studies on tissue [alpha]1A-adrenoceptors and correlated best with the antagonists published affinities for the expressed [alpha]1a-adrenoceptor clone. For the rat spleen [alpha]1-adrenoceptor mediated contractions the antagonist pA2 values were consistent with their affinities in binding studies on tissue [alpha]1B-adrenoceptors and correlated best with the antagonists published affinities for the expressed [alpha]1-adrenoceptor clone. It was concluded that the functional [alpha]1-adrenoceptor in the rat epididymal vas deferens and human prostate was the [alpha]1A-subtype and this is the same as the expressed [alpha]1a-clone, while in the rat spleen it was the [alpha]1B-subtype and this is the same as the expressed [alpha]1b-clone. The [alpha]1A-adrenoceptor mediated contraction of the rat epididymal vas deferens appeared to depend upon activation of protein kinase C by diacylglycerol, resulting in the influx of extracellular Ca2+ through voltage-gated Ca2+ channels. The [alpha]1B-adrenoceptor mediated contraction of the rat spleen consisted of an initial phasic contraction due to release of intracellular Ca2+ and a larger tonic contraction due to capacitative Ca2+ influx through non-voltage-gated Ca2+ channels and which may involve a tyrosine kinase. The [alpha]1A-adrenoceptor mediated contraction in the human prostate was dependent on both influx of extracellular Ca2+ through a partially nifedipine sensitive channel and a component which may possibly be due to either release of Ca2+ from ryanodine sensitive intracellular stores or a Ca2+ independent mechanism.

Type: Thesis (Doctoral)
Qualification: Ph.D
Title: [alpha]1-adrenoceptor subtypes in the rat isolated epididymal vas deferens, spleen and human prostate and their signal transduction mechanisms
Open access status: An open access version is available from UCL Discovery
Language: English
Additional information: Thesis digitised by ProQuest.
Keywords: Biological sciences
URI: https://discovery.ucl.ac.uk/id/eprint/10099779
Downloads since deposit
18Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item