Myocardial and mitochondrial function in potassium depletion cardiomyopathy
| Autor: | Cooper G th, Zujko Kj, Carlos E. Harrison, Coleman Hn rd |
|---|---|
| Rok vydání: | 1972 |
| Předmět: |
medicine.medical_specialty
Normal diet Potassium Cardiomyopathy chemistry.chemical_element Oxidative Phosphorylation Potassium Chloride Contractility Internal medicine medicine Animals Molecular Biology Potassium Deficiency CATS Valinomycin Myocardium Heart Papillary Muscles medicine.disease Dietary Potassium Diet Mitochondria Muscle Endocrinology chemistry Cats Potassium Isotopes Potassium deficiency Cardiology and Cardiovascular Medicine Cardiomyopathies Intracellular |
| Zdroj: | Journal of molecular and cellular cardiology. 4(6) |
| ISSN: | 0022-2828 |
| Popis: | The purpose of this investigation was to define mitochondrial function in cats with depressed cardiac contractility secondary to dietary depletion of potassium (cardiomyopathy). Cats were maintained on one of the following four programs: (i) normal diet (controls); (ii) potassium-deficient diet for an average of 36 days; (iii) potassium-deficient diet for an average of 38 days and then a normal diet for an average of 36 days; (iv) potassium-deficient diet plus 120 mequiv of potassium chloride/l of drinking water for an average of 43 days. Normal intracellular exchangeable 42K averaged 154 ± 3 (s.e.) mequiv/l of intracellular water while potassium-deficient diet resulted in a decrease to 92 ± 9 mequiv/l. Mechanics of contractility were characterized by force-velocity and length-tension relations in isolated right ventricular papillary muscles. Indexes of oxidative phosphorylation and the rate of potassium transport induced by valinomyein were assessed in the mitochondria. The average force-velocity and length-tension curves were greatly depressed in the low potassium group (P < 0.001). Normal myocardial muscle mechanics were demonstrated in papillary muscles of animals given potassium chloride in addition to potassium-deficient diet and in muscles from animals fed a normal diet after potassium deficiency was produced. Respiratory control ratios were depressed 15% from control values (P < 0.05) in potassium deficiency but were equal to control values in repleted animals. Valinomycin-induced uptake of potassium was diminished 15% in the potassium-deficient hearts (P < 0.02). The rate of influx of potassium was depressed 22% from control (P < 0.02). These data suggest that a severe potassium-deficient state is associated with severe impairment of myocardial mechanical function and moderate changes in mitochondrial function that are reversible with repletion of dietary potassium. |
| Databáze: | OpenAIRE |
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