Document Detail

Ischemic injury to the conducting system of the heart. Involvement of myocardial lysosomes.
MedLine Citation:
PMID:  431098     Owner:  NLM     Status:  MEDLINE    
The conducting system was studied in an in situ perfused swine heart preparation with reduced coronary flow (ischemia) using perfusate containing high and low levels of glucose (26.6 versus 8.6mM) with and without insulin. Coronary flow was maintained at normal levels for 60 minutes in control hearts. In ischemic hearts flow was reduced to about 50 percent of control levels for 30 minutes. Ultrastructural studies documented only subtle modifications of Purkinje fibers in ischemic hearts. Glycogen depletion and disruption of cell junctions were observed in some fibers. One consistent finding was the activation of the lysosomal system. The outer membranes of primary lysosomes appeared herniated and in some cases disrupted, and small vesicles containing hydrolytic enzymes were seen in association with the Golgi apparatus and larger primary lysosomes. Specimens prepared for the demonstration of acid phosphatase indicated a redistribution of hydrolytic enzymes in Purkinje fibers with a depostion of acid hydrolases in smaller lysosomal vesicles, the transverse and side-to-side junctions between cells, and occasionally in the sarcoplasmic reticulum. Enriched perfusate containing high levels of glucose with insulin appeared to have no therapeutic effects in terms of the structure of the Purkinje fibers. The results suggest that alterations in the lysosomal system may be one of the earliest structural changes which occur in oxygen-deficient hearts.
L P McCallister; A J Liedtke; H C Hughes
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The Journal of thoracic and cardiovascular surgery     Volume:  77     ISSN:  0022-5223     ISO Abbreviation:  J. Thorac. Cardiovasc. Surg.     Publication Date:  1979 May 
Date Detail:
Created Date:  1979-06-29     Completed Date:  1979-06-29     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0376343     Medline TA:  J Thorac Cardiovasc Surg     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  647-61     Citation Subset:  AIM; IM    
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MeSH Terms
Acid Phosphatase / metabolism
Coronary Disease / pathology*
Glucose / pharmacology
Golgi Apparatus / ultrastructure
Heart Conduction System / ultrastructure*
Hydrolases / metabolism
Insulin / pharmacology
Lysosomes / enzymology,  ultrastructure*
Mitochondria, Heart / ultrastructure
Myocardium / enzymology,  ultrastructure*
Myofibrils / ultrastructure
Purkinje Fibers / ultrastructure
Sarcoplasmic Reticulum / ultrastructure
Reg. No./Substance:
11061-68-0/Insulin; 50-99-7/Glucose; EC 3.-/Hydrolases; EC Phosphatase

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

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