ISSN:
1432-1912
Keywords:
α1/α2-Adrenoceptors
;
Prazosin
;
Yohimbine
;
Rat aorta
;
Pithed rat
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The postsynaptic α-adrenoceptors in rat aorta and in pithed rat were investigated according to their sensitivity to nine α-adrenergic agonists and to the selective antagonists yohimbine (α2) and prazosin (α1) and the non-selective one, phentolamine. In addition, in radioligand binding studies, the affinity and selectivity of the drugs were determined on rat cerebral cortex using [3H] yohimbine and [3H] prazosin. On rat aorta, prazosin is 1,000 times more potent than yohimbine against each α-adrenoceptor agonist, whether α1- or α2-selective. Rat aorta probably contains only α1-adrenoceptors. Pressor effects in pithed rats are mediated by post-junctional α1- and α2-adrenoceptors. The dose-response curve for α-methylnorepinephrine in the presence of prazosin, using Hofstee's plots, revealed α1- and α2-adrenoceptors, respective proportions being 80.5 and 19.5%
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00518771
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