What question did this study set out to answer?

To determine which alpha 1-adrenoceptor subtypes mediate noradrenaline-induced arterial contractions in rat superior mesenteric artery ring preparations.

January 1, 1998Pharmacology

Heterogeneity of α1-Adrenoceptor Subtypes Mediating Noradrenaline-Induced Contractions of theRat Superior Mesenteric Artery

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Population

Rat superior mesenteric artery ring segments

Comparison

Subtype-selective alpha 1-adrenoceptor… vs Noradrenaline-induced contractions without…

Design

Preclinical

Authors

MYMariam H.M. YousifKuwait University EKElizabeth A. KadavilKuwait University MOMabayoje A. OriowoKuwait University

Discussion

Member takes

Implication

Hypothesis-generating for alpha1D/L roles in vascular tone; leaves open translation to human arteries or selective antagonists.

Key Points

To determine which alpha 1-adrenoceptor subtypes mediate noradrenaline-induced arterial contractions in rat superior mesenteric artery ring preparations.
Mounted isolated ring segments of rat superior mesenteric arteries to measure isometric contractile responses to noradrenaline and selective alpha 1-adrenoceptor ligands.
Assessed pharmacological profiles using subtype-selective antagonists (prazosin, WB 4101, BMY 7378, spiperone, 5-methylurapidil, and chloroethylclonidine) and the agonist A 61,603.
Prazosin, WB 4101, and BMY 7378 potently antagonized noradrenaline contractions, with WB 4101 and BMY 7378 displaying Schild slopes significantly different from 1, reflecting noncompetitive antagonism.
Pretreatment with chloroethylclonidine (100 µmol/L) shifted the noradrenaline concentration-response curve to the right, causing an approximate 100-fold reduction in potency.
The selective alpha 1A-adrenoceptor agonist A 61,603 stimulated arterial contractions that were antagonized by prazosin with low affinity, indicating the involvement of alpha 1D- and alpha 1L-adrenoceptor subtypes.

Structured PICO

Population

Rat superior mesenteric artery ring segments

Intervention

Subtype-selective alpha 1-adrenoceptor antagonists (prazosin, WB 4101, BMY 7378, spiperone, 5-methylurapidil, chloroethylclonidine) and selective alpha 1A-adrenoceptor agonist (A 61,603)

Comparator

Noradrenaline-induced contractions without antagonists

Outcome

Noradrenaline-induced contractionssurrogate

Alpha 1D- and possibly alpha 1L-adrenoceptor subtypes mediate noradrenaline-induced contractions in the rat superior mesenteric artery.

Cite This Study

Yousif et al. (1998) studied this question.

synapsesocial.com/papers/6a898273991508d05dc989ea https://doi.org/10.1159/000028198

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Heterogeneity of α1-Adrenoceptor Subtypes Mediating Noradrenaline-Induced Contractions of theRat Superior Mesenteric Artery

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Heterogeneity of α1-Adrenoceptor Subtypes Mediating Noradrenaline-Induced Contractions of theRat Superior Mesenteric Artery

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider