Document Detail

Effect of ischemia on mechanical function and high-energy phosphates in rabbit myocardium.
MedLine Citation:
PMID:  7091347     Owner:  NLM     Status:  MEDLINE    
This study was designed to evaluate the effect of ischemia and reperfusion on myocardial mechanical function and high-energy phosphates in the neonate. All studies were performed utilizing the isolated arterially perfused septal preparation of newborn and adult rabbit hearts that were maintained at 27, 33, or 37 degrees C and paced at 90 beats/min. After mechanical function had been stabilized, 60 min of global ischemia was induced and was followed by 60 min of reperfusion. The muscle was kept in a humidified, warm, oxygen-poor atmosphere. During ischemia, developed tension (DT) and maximal rate of tension development (+dT/dtmax) declined at the same rate in the newborn and the adult, and the values at the end of ischemia were not significantly different from 0. The resting tension (RT) increased significantly in the two age groups during ischemia, but the increase in the newborn was significantly less than that in the adult. After 60 min of reperfusion, the recovery of +dT/dtmax in the newborn was significantly greater than that in the adult at each temperature. Tissue ATP content in the newborn was significantly greater than that in the adult, both at the end of ischemia and after reperfusion. Importantly, a significant correlation (r = 0.90) between the recovery of +dT/dtmax and tissue ATP content was found. These data indicate that 1) the newborn myocardium is more resistant to ischemia than the adult myocardium and 2) this resistance might be explained by less depletion of myocardial ATP levels during ischemia.
K Nishioka; J M Jarmakani
Related Documents :
3243307 - Efficacy of 15-(123i)-p-iodophenyl pentadecanoic acid (ippa) in assessing myocardial me...
20083167 - Exercise preconditioning reduces neuronal apoptosis in stroke by up-regulating heat sho...
7139197 - Effect of muscarine on release of catecholamines from the perfused adrenal gland of the...
24279747 - Effects of a six-month intradialytic physical activity program and adequate nutritional...
3907677 - Comparison of oxyfedrine and atenolol in angina pectoris--a double-blind study.
14990677 - Does gender affect human pulmonary gas exchange during exercise?
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  242     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1982 Jun 
Date Detail:
Created Date:  1982-08-26     Completed Date:  1982-08-26     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H1077-83     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Adenosine Triphosphate / metabolism*
Animals, Newborn / physiology*
Coronary Disease / physiopathology*
Heart / physiopathology*
Myocardial Contraction
Phosphocreatine / metabolism*
Time Factors
Grant Support
Reg. No./Substance:
56-65-5/Adenosine Triphosphate; 67-07-2/Phosphocreatine

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

Previous Document:  Effects of left atrial stretch in cardiac-denervated and intact conscious dogs.
Next Document:  Endogenous triacylglycerol metabolism in diabetic heart.