Back to Search Start Over

Selective agonists reveal alpha(1A)- and alpha(1B)-adrenoceptor subtypes in caudal artery of the young rat.

Authors :
Parés-Hipólito J
Gómez-Zamudio JH
Gallardo-Ortiz IA
López-Guerrero JJ
Santamaría-Ortiz J
Ibarra M
Villalobos-Molina R
Source :
Autonomic & autacoid pharmacology [Auton Autacoid Pharmacol] 2006 Oct; Vol. 26 (4), pp. 371-8.
Publication Year :
2006

Abstract

Multiple alpha(1)-adrenoceptors were evaluated in caudal artery of the young Wistar rat using selective agonists and antagonists. Arteries were exposed to the selective alpha(1A)-adrenoceptor agonist, A-61603 (N-[5-(4,5-dihydro-1H-imidazol-2-yl)-2-hydroxy-5,6,7,8-tetrahydronaphthalen-1-yl] methanesulfonamide) or to phenylephrine and to prazosin (alpha(1)-adrenoceptor antagonist), or the selective alpha(1A)-adrenoceptor antagonists 5-methylurapidil, RS 100329 (5-methyl-3-[3-[4-[2-(2,2,2,-trifluoroethoxy)phenyl]-1-piperazinyl]propyl]-2,4-(1H)-pyrimidinedione), RS 17053 (N-[2(2-cyclopropylmethoxy) ethyl]-5-chloro-alpha, alpha-dimethyl-1H-indole-3-ethanamide), and the selective alpha(1D)-adrenoceptor antagonist BMY 7378 (8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro[4.5] decane-7,9-dione). Results showed a 100-fold higher potency of A-61603 for the alpha(1)-adrenoceptor present in the artery, compared with phenylephrine. Prazosin displaced both agonists with high affinity, whereas 5-methylurapidil, RS 100329 and RS 17053 displaced A-61603 with high affinity, indicating the presence of alpha(1A)-adrenoceptors. The selective alpha(1A)-adrenoceptor antagonists blocked phenylephrine responses with low affinity, suggesting that phenylephrine activated a second receptor population in caudal artery. BMY 7378 antagonized with low affinity both A-61603 and phenylephrine-induced contractions, indicating absence of alpha(1D)-adrenoceptors in the vessel. The results suggest that functional alpha(1B)-adrenoceptors are present in caudal arteries of the young Wistar rat.

Details

Language :
English
ISSN :
1474-8665
Volume :
26
Issue :
4
Database :
MEDLINE
Journal :
Autonomic & autacoid pharmacology
Publication Type :
Academic Journal
Accession number :
16968476
Full Text :
https://doi.org/10.1111/j.1474-8673.2006.00380.x