Korean Circ J.  1987 Sep;17(3):479-490. 10.4070/kcj.1987.17.3.479.

A Study on the Cardiac Myofibrillar ATPase Activity in Diabetic Rats

• Ryu WS
• Ryoo UH
• Seo JD
• Lee YW

• KMID: 2093216
• DOI: http://doi.org/10.4070/kcj.1987.17.3.479

Abstract

Diabetes mellitus is known to be associated with a specific cardiomyopathy. This is evident from the clinical-pathological work and the epidemiologic data. An investigation was made in this study to determine whether diabetic cardiomyopathy in rats is associated with an alteration of biochemical characteristics of cardiac contractile proteins. Rats were made diabetic with intravenous injection of streptozotocin and hearts removed 8 weeks later for the isolation of myofibrils. The basal ATPase activity of myofibrils from diabetic hearts was significantly lower than that of the controls, suggesting the presence of some subtle structural and conformational changes in diabetic myofibrils. The activating effect of Mg ions on the myofibrillar actomyosin system of rat heart muscle was also demonstrated. Sodium dodecylsulfate gel electrophoresis showed the presence of myosin heavy chain, light chain 1 and 2, actin and troponin but failed to reveal differences in the patterns of these contractile proteins of light subunits between diabetics and controls. The deficiency in utilization of energy rich phosphates by the myofibrillar protein may be one of of the main mechanisms of cardiodepression observed in diabetic hearts. The cardiac myofibrillar ATPase activity may be one of useful measurements in evaluating pathophysiological states of cardiac contractile proteins.

Keyword

Diabetic Cardiomyopathy; Streptozotocin-induced diabetes; Rat myocardium; Myofibrillar ATPase activity

MeSH Terms

Actins
Actomyosin
Adenosine Triphosphatases*
Animals
Cardiomyopathies
Contractile Proteins
Diabetes Mellitus
Diabetic Cardiomyopathies
Electrophoresis
Heart
Injections, Intravenous
Ions
Myocardium
Myofibrils
Myosin Heavy Chains
Phosphates
Rats*
Sodium
Streptozocin
Troponin
Actins
Actomyosin
Adenosine Triphosphatases
Contractile Proteins
Ions
Myosin Heavy Chains
Phosphates
Sodium
Streptozocin
Troponin