Document Detail

Investigation into some imidazoline compounds, with respect to peripheral alpha-adrenoceptor stimulation and depression of cardiovascular centers.
MedLine Citation:
PMID:  628     Owner:  NLM     Status:  MEDLINE    
Peripheral alpha-adrenoceptor stimulation was tested by means of hypertensive effects of the drugs following i.v. injection in spinal rats. Naphazoline (NP), oxymetazoline (OM), St 91-2-(2,6-diethylphenylimino)-2-imidazolidine--and St 1697--2-(2-ethyl, 6-methylphenylimino)-2-imidazolidine--were 3 to 5 times more potent in tthis respect thatn clonidine (CLON) whereas St 363--2-(2,4-dichlorophenylimino)-2-imidazolidine--and xylazine (XY) exerted only approx. 1/20 the effect of that of clonidine. Sympathoinhibitory activity after i.v. injection was tested by the bradycardiac effect in vagotomized rats; St 1697, St 363 and XY were active, approx. 1/10-1/30 of CLON, whereas NP, OM and St 91 were inactive. However, following intracisternal ( injection of cardiovascular depression, typical for clonidine: (1) in dogs with blocked beta-adrenoceptors, the drugs facilitated the vagally meditated cardiodepressor reflex in response to baroreceptor stimulation by i.v. injection of angiotensin; (2) in dogs treated with atropine and in (3) vagotomized cats (only NP, OM and St 363) a long lasting decrease in heart rate was observed. Some of the experiments were complicated by increases in blood pressure, due to the "leakage" of small amounts of the highly vasopressor active drugs, from the cisternal spaces into the peripheral circulation. The majority of results indicated, that the central cardiovascular depressor effects of the tested drugs depend on their alpha-adrenoreceptor stimulating potency and on their ability to penetrate from cerebrospinal fluid or from the blood to cardiovascular centers. Relationships between the ability for penetration and the lipoid affinity are discussed.
W Kobinger; L Pichler
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Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Naunyn-Schmiedeberg's archives of pharmacology     Volume:  291     ISSN:  0028-1298     ISO Abbreviation:  Naunyn Schmiedebergs Arch. Pharmacol.     Publication Date:  1975  
Date Detail:
Created Date:  1976-03-01     Completed Date:  1976-03-01     Revised Date:  2010-03-12    
Medline Journal Info:
Nlm Unique ID:  0326264     Medline TA:  Naunyn Schmiedebergs Arch Pharmacol     Country:  GERMANY, WEST    
Other Details:
Languages:  eng     Pagination:  175-91     Citation Subset:  IM    
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MeSH Terms
Adrenergic alpha-Agonists*
Atropine / pharmacology
Blood Pressure / drug effects*
Brain / drug effects
Clonidine / pharmacology
Heart Rate / drug effects*
Imidazoles / pharmacology*
Naphazoline / pharmacology
Oxymetazoline / pharmacology
Pressoreceptors / drug effects
Receptors, Adrenergic / drug effects*
Reflex / drug effects
Vagus Nerve / physiology
Vasomotor System / drug effects*
Xylazine / pharmacology
Reg. No./Substance:
0/Adrenergic alpha-Agonists; 0/Imidazoles; 0/Receptors, Adrenergic; 1491-59-4/Oxymetazoline; 4205-90-7/Clonidine; 51-55-8/Atropine; 7361-61-7/Xylazine; 835-31-4/Naphazoline

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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