Document Detail


Pharmacokinetics and dynamic effects of diltiazem in the isolated guinea-pig heart.
MedLine Citation:
PMID:  3375187     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Myocardial pharmacokinetics of diltiazem showed two-compartment characteristics in the isolated, spontaneously beating guinea-pig heart. Half-times of initial and terminal drug accumulation phases were about 2.1 and 14.4 min., respectively. At 1 microgram ml-1 (2.4 microM) in the perfusion liquid the average concentration of diltiazem in the myocardium at steady state was about 16 micrograms g-1 (38.6 microM) with 17% referable to the deepest, possibly intracellular compartment. Increasing diltiazem concentrations from 13 to 889 ng ml-1 (31-2144 nM) produced a progressive increase in coronary flowrate from 100 to 174%. The computed Em- and EC50-values were 73.2% and 187 nM, respectively. Oxygen consumption decreased to 27.6% showing Em = 106% and IC50 = 1536 nM. Amplitude and velocity of myocardial contraction decreased to about 6% and 2%; Em = 101% and 104%, IC50 = 266 and 186 nM, respectively. Heart beating frequency decreased to 63% exhibiting Em = 58% and IC50 = 2015 nM. The PQ- and QRS-intervals increased to 133% and 112%, respectively. The frequency-corrected QT-interval decreased to 81.6%. Our findings demonstrate a relatively rapid and moderate accumulation of diltiazem in the guinea-pig heart accompanied by a marked increase in coronary flow, progressive and pronounced negative inotropic and chronotropic effects and a less than proportional decrease in oxygen consumption.
Authors:
H K Jensen; F Nielsen-Kudsk
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Publication Detail:
Type:  In Vitro; Journal Article    
Journal Detail:
Title:  Pharmacology & toxicology     Volume:  62     ISSN:  0901-9928     ISO Abbreviation:  Pharmacol. Toxicol.     Publication Date:  1988 Mar 
Date Detail:
Created Date:  1988-06-30     Completed Date:  1988-06-30     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8702180     Medline TA:  Pharmacol Toxicol     Country:  DENMARK    
Other Details:
Languages:  eng     Pagination:  166-71     Citation Subset:  IM    
Affiliation:
Institute of Pharmacology, University of Aarhus, Denmark.
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MeSH Terms
Descriptor/Qualifier:
Animals
Coronary Circulation / drug effects
Diltiazem / pharmacokinetics*,  pharmacology
Female
Guinea Pigs
Heart / drug effects*
Heart Rate / drug effects
Male
Myocardial Contraction / drug effects
Myocardium / metabolism
Oxygen Consumption / drug effects
Chemical
Reg. No./Substance:
42399-41-7/Diltiazem

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


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