The α1A-adrenoceptor subtype mediates contraction in rat femoral resistance arteries
| Autor: | Chris Hillier, Allan MacDonald, Yagna P. R. Jarajapu |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Male
medicine.medical_specialty Contraction (grammar) Tetrahydronaphthalenes In Vitro Techniques Clonidine Piperazines Dioxanes Norepinephrine Phenylephrine chemistry.chemical_compound Chloroethylclonidine Quinoxalines Receptors Adrenergic alpha-1 Internal medicine medicine Prazosin Animals Naphthyridines Rats Wistar Adrenergic alpha-Antagonists Pharmacology Dose-Response Relationship Drug Imidazoles Adrenergic alpha-2 Receptor Antagonists Isoquinolines Rats Femoral Artery Endocrinology chemistry Vasoconstriction Brimonidine Tartrate Circulatory system Adrenergic alpha-1 Receptor Antagonists Vascular Resistance Adrenergic alpha-1 Receptor Agonists medicine.symptom Adrenergic alpha-Agonists Myograph Muscle contraction medicine.drug |
| Zdroj: | European Journal of Pharmacology. 422:127-135 |
| ISSN: | 0014-2999 |
| Popis: | In this study, alpha(1)-adrenoceptor subtypes were characterised in rat femoral resistance arteries mounted on a small vessel myograph. A-61603 was found to be more potent than noradrenaline and phenylephrine in these arteries. Brimonidine (UK 14304) could not evoke any contractile responses and the sensitivity to noradrenaline and phenylephrine was not affected by (8aR,12aS,13aS)-5,8,8a,9,10,11,12,12a,13a-decahydro-3-methoxy-12-(ethylsulphonyl)-6H-isoquino[2,1-g][1,6]-naphthyridine (RS 79948), ruling out the presence of alpha(2)-adrenoceptors. Prazosin, 5-methyl-urapidil and 2-([2,6-dimethoxyphenoxyethyl]aminomethyl)-1,4-benzodioxane (WB 4101) produced rightward shifts in the sensitivity to noradrenaline, giving pA(2) values of 9.6, 9.4 and 10.4, respectively, in agreement with the presence of alpha(1A)-adrenoceptors. (8-[2-[4-(2-Methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro[4.5]decane-7,9-dione (BMY 7378; 1 microM) produced a small shift in the sensitivity of noradrenaline giving a pK(B) of 7.2. In the presence of 300 nM 5-methyl-urapidil, sensitivity to noradrenaline was not further shifted by 1 microM BMY 7378. Responses to noradrenaline were unaffected by the alpha(1B)-adrenoceptor alkylating agent chloroethylclonidine (1 microM). These results suggest alpha(1A)-adrenoceptors mediate contractile responses to noradrenaline in rat femoral resistance arteries. |
| Databáze: | OpenAIRE |
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