ISSN:
0899-0042
Keywords:
optical isomers
;
enantiomers
;
vascular smooth muscle
;
5-hydroxytryptamine
;
noradrenaline
;
potassium
;
calcium
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The effect of the enantiomers of a novel 5-HT2 receptor antagonist, (±)-(1R,3S)-1-[2-[4-[3-(p-fluorophenyl)-1-indanyl]-piperazinyl]ethyl]-2-imidazolidinone, was studied on serotonin (5-HT), noradrenaline (NA), potassium (K+), and calcium (Ca2+)-induced contractions in isolated rat thoracic aorta. The enantiomers shifted the 5-HT, NA, K+, and Ca2+ concentration-response curves to the right in a concentration-dependent manner and depressed the maximal contractile responses. The (+)-enantiomer was a far more potent inhibitor of 5-HT-induced contractions than the (-)-enantiomer. The (+)-enantiomer and phentolamine, both at 10-6 M, had equal inhibitory effects on NA-evoked contractions. The (+)-enantiomer was again more potent in inhibiting NA-induced contractions than the (-)-enantiomer. Both enantiomers had an equieffective inhibitory effect on K+ and Ca2+-induced contractions. The results show that the 5-HT and α-adrenoceptor antagonism of the two enantiomers is stereoselective, the (+)-enantiomer being more potent than the (-)-enantiomer. In contrast the enantiomers had equal, nonstereoselective inhibitory effects on K+ and Ca2+-evoked contractions.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chir.530020406
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