Abstract |
The pharmacological profile of a newly synthesized imidazole derivative, DJ-7141, was examined with special reference to alpha-2 adrenoceptors. In the rat vas deferens and dog mesenteric artery, DJ-7141 at concentrations over 10(-9) M selectively acted on the presynaptic alpha-2 adrenoceptors on the sympathetic nerve terminals and inhibited the contractions induced by electrical transmural stimulation. The potency of DJ-7141 was almost the same as those of clonidine and guanabenz. DJ-7141 also acted on the postsynaptic alpha-2 adrenoceptors to contract the dog saphenous vein. However, no alpha-1 agonist and antagonist actions were found at concentrations showing presynaptic alpha-2 agonist activity. In contrast to DJ-7141, clonidine produced an apparent contraction in the dog mesenteric artery, and the response was inhibited by prazosin. In urethane-anesthetized rats, clonidine at doses ranging from 0.003 mg/kg to 0.03 mg/kg produced a marked and prolonged hypotension, while DJ-7141 at such doses failed to produce a reduction of blood pressure. From these results, it is suggested that, in contrast to clonidine and other alpha-2 agonists, DJ-7141 is a unique alpha-2 agonist which shows high affinity to peripheral alpha-2 adrenoceptors but only a mild hypotensive activity.
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Authors | I Muramatsu, M Oshita, S Hashimoto, S Kigoshi |
Journal | Japanese journal of pharmacology
(Jpn J Pharmacol)
Vol. 41
Issue 1
Pg. 61-8
(May 1986)
ISSN: 0021-5198 [Print] Japan |
PMID | 2874252
(Publication Type: Journal Article)
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Chemical References |
- Adrenergic alpha-Agonists
- Antihypertensive Agents
- Imidazoles
- Receptors, Adrenergic, alpha
- DJ 7141
- Clonidine
- Norepinephrine
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Topics |
- Adrenergic alpha-Agonists
(pharmacology)
- Animals
- Antihypertensive Agents
- Blood Pressure
(drug effects)
- Clonidine
(pharmacology)
- Dogs
- Female
- Imidazoles
(pharmacology)
- Male
- Mesenteric Arteries
(drug effects, physiology)
- Muscle Contraction
(drug effects)
- Muscle, Smooth
(drug effects, physiology)
- Muscle, Smooth, Vascular
(drug effects, physiology)
- Norepinephrine
(pharmacology)
- Rats
- Rats, Inbred Strains
- Receptors, Adrenergic, alpha
(drug effects, physiology)
- Saphenous Vein
(drug effects)
- Vas Deferens
(drug effects, physiology)
- Vasoconstriction
(drug effects)
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