Receptor binding profile of cyclazosin, a new alpha 1B-adrenoceptor antagonist.
The binding profile of cyclazosin, a new prazosin-related alpha 1-adrenoceptor antagonist, at alpha 1-, alpha 2-adrenoceptors, dopamine D2 and 5-HT1A receptors was compared to that of 5-methylurapidil, spiperone, risperidone and other prazosin-related ligands. In addition, cyclazosin was investigated at native and cloned alpha 1-adrenoceptor subtypes. Cyclazosin showed high specificity for alpha 1-adrenoceptors and a 10-15-fold selectivity for alpha 1B (alpha 1b)-adrenoceptors with respect to the alpha 1A (alpha 1a) subtype (pKi values of 9.23-9.57 and 8.18-8.41, respectively). However, it failed to discriminate between cloned alpha 1b and alpha 1d-adrenoceptors (pKi values of 9.23 and 9.28, respectively).
Giardinà
D
D
Department of Chemical Sciences, University of Camerino, Italy.
Crucianelli
M
M
Melchiorre
C
C
Taddei
C
C
Testa
R
R
D000317:Adrenergic alpha-Antagonists / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D008297:Male; D011224:Prazosin / Q000378:metabolism / Q000494:pharmacology; D011799:Quinazolines / Q000378:metabolism / Q000494:pharmacology*; D011810:Quinoxalines / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism
D000317:Adrenergic alpha-Antagonists; D011799:Quinazolines; D011810:Quinoxalines; D018340:Receptors, Adrenergic, alpha-1; C080462:cyclazosin; D011224:Prazosin