Document Detail


Reduced myocardial response to calcium during endotoxin shock in the cat.
MedLine Citation:
PMID:  7389063     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The hemodynamic effects of short intravenous infusions of calcium chloride were examined in anaesthetized cats before and during shock induced with E coli endotoxin (2 mg/kg). In normal cats calcium (5 mg kg-1 min-1 or 10 mg kg-1 min-1 infused for 5 minutes) increased left ventricular (LV) dP/dtmax, LVdP/dt at fixed isovolumic pressures, systemic arterial blood pressure and, usually, cardiac output. These hemodynamic changes lasted approximately 20 minutes. During endotoxin shock the calcium response (cardiac output, LVdP/dt, blood pressure) was greatly reduced. This diminished responsiveness was evident as early as 0.5--1 hour after endotoxin and lasted throughout the 4-hour shock period. The duration of the hemodynamic response was also decreased during shock. Reduced myocardial sensitivity to a number of cardiac stimulants, including beta-adrenoceptor stimulants and agents augmenting cellular cAMP/levels, occurs in this and other shock models. The present results suggest that this altered sensitivity is attributable to changes in the actual contraction processes rather than beta-adrenoceptor desensitization or a defect in the cAMP system. Since this altered calcium response does not occur in vitro the results might suggest the presence, in shock, of a circulating agent acting at the level of cellular calcium exchange.
Authors:
D J McCaig; J R Parratt
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Circulatory shock     Volume:  7     ISSN:  0092-6213     ISO Abbreviation:  Circ. Shock     Publication Date:  1980  
Date Detail:
Created Date:  1980-09-23     Completed Date:  1980-09-23     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0414112     Medline TA:  Circ Shock     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  23-30     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure / drug effects
Calcium / pharmacology*
Cardiac Output / drug effects
Cats
Dose-Response Relationship, Drug
Endotoxins*
Heart Rate / drug effects
Hemodynamics / drug effects
Myocardial Contraction
Myocardium / metabolism*
Shock / etiology*
Time Factors
Chemical
Reg. No./Substance:
0/Endotoxins; 7440-70-2/Calcium

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


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