Changes in microsomal membrane phospholipids and fatty acids and in activities of membrane-bound enzyme in diabetic rat heart.
Basic Res Cardiol
; 92(4): 214-22, 1997 Aug.
Article
en En
| MEDLINE
| ID: mdl-9342428
ABSTRACT
Diabetes mellitus is associated with alterations in lipid metabolism and cardiac dysfunction despite an absence of coronary arteriosclerotic changes. To investigate mechanisms of cardiac dysfunction in diabetic cardiomyopathy, we studied the relation between activities of membrane-bound enzymes and surrounding phospholipids in rats with diabetes induced with a single intravenous injection of streptozotocin (65 mg/kg). We found that total phospholipid content of sarcoplasmic reticulum membrane increased significantly 8 weeks after treatment with streptozotocin owing to increases in phosphatidylcholine and phosphatidylethanolamine, a decrease in arachidonic acid, and an increase in docosahexaenoic acid in the early stage of diabetes. Sarcolemmal Na+/K(+)-ATPase activity and the number of receptors decreased in isolated cardiomyocytes of diabetic rats 8 weeks after streptozotocin administration. The Ca2+ uptake of both sarcoplasmic reticulum and mitochondria decreased simultaneously in permeabilized, isolated cardiomyocytes from diabetic rats. The depression of membrane-bound enzyme activities was correlated with alterations in phospholipids, which are closely related to the microenvironment of membrane-bound enzymes and influence intracellular Ca2+ metabolism. Because these changes in phospholipids and fatty acids were reversible with insulin therapy, they are diabetes-specific and might be a cause of cardiac dysfunction in diabetes.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fosfolípidos
/
ATPasa Intercambiadora de Sodio-Potasio
/
Diabetes Mellitus Experimental
/
Ácidos Grasos
/
Microsomas
/
Cardiomiopatías
/
Miocardio
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Basic Res Cardiol
Año:
1997
Tipo del documento:
Article
País de afiliación:
Japón