Document Detail


Linear dose response and quantitative attenuation by potassium of the inotropic action of acetylstrophanthidin.
MedLine Citation:
PMID:  872494     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
To evaluate the nature of the inotropic dose response of digitalis and to determine the effects of potassium on this response, isometrically contracting isolated supported right ventricular cat papillary muscles were studied relative to their peak tension and peak dT/dt increases to physiologic cumulative doses of acetylstrophanthidin (ACS) in different extracellular potassium concentrations in the muscle bath. The inotropic dose response to ACS was observed to be linear in cumulative glycoside concentrations ranging from 0.40 to 4.23 X 10(-7) M ACS in 3.5 mM K+ medium and from 1.22 to 7.47 X 10(-7) M ACS in 7.0 mM K+ medium. The influence of potassium alterations in the muscle bath from the low to the high K+ concentrations prior to ACS resulted in marked attenuation of the positive inotropic property of ACS. From these data, it is concluded that the dose inotropic response of digitalis is linear, with small doses producing proportionally the same effects as larger doses, and that extracellular potassium markedly influences this linear dose response such that higher K+ concentrations considerably attenuate the positive inotropic response of digitalis.
Authors:
G Lee; R Zelis; D T Mason
Related Documents :
9663924 - Angiotensin ii and endothelin-1 receptor antagonists have cumulative hypotensive effect...
3241244 - Baroreflex modulation of central angiotensin ii pressor responses in conscious rabbits.
8480624 - Pharmacologic profile of trandolapril, a new angiotensin-converting enzyme inhibitor.
3929314 - Tyramine pressor sensitivity changes during deprenyl treatment.
22757184 - We-c-brb-06: clinical impact of uncertainties in the mean excitation energy of human ti...
3089644 - Assessment of immunochemical methods for determining low concentrations of albumin in u...
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Clinical pharmacology and therapeutics     Volume:  22     ISSN:  0009-9236     ISO Abbreviation:  Clin. Pharmacol. Ther.     Publication Date:  1977 Jul 
Date Detail:
Created Date:  1977-08-25     Completed Date:  1977-08-25     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0372741     Medline TA:  Clin Pharmacol Ther     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  34-41     Citation Subset:  AIM; IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Cats
Dose-Response Relationship, Drug
Electric Stimulation
Myocardial Contraction / drug effects*
Osmolar Concentration
Potassium / pharmacology*
Strophanthidin / analogs & derivatives*,  antagonists & inhibitors,  pharmacology
Chemical
Reg. No./Substance:
66-28-4/Strophanthidin; 7440-09-7/Potassium

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


Previous Document:  Digoxin toxicity in patients with normokalemic potassium depletion.
Next Document:  Response optimization of drug dosage: antiarrhythmic studies with tocainide.