Histochemical studies on the conduction system of diabetic rat hearts.
We studied the metabolism of the conduction system and the working myocardium in diabetic rat hearts by enzyme histochemistry. The experiment was performed three weeks following the administration of streptozotocin (65 mg/kg) to male Wistar rats. The hearts were quickly excised and tissue was frozen immediately by immersion in isopentane at -30 degrees C and cut into 16 microns thick sections in a cryostat. The PAS positive reaction was increased in the conduction system compared to the working myocardium in control rats. In diabetic rat hearts, these reactions in the working myocardium and the conduction system were strongly increased compared to control hearts. Several enzyme activities, such as phosphofructokinase, pyruvate dehydrogenase, glucose-6-phosphate dehydrogenase, Na-K ATPase, were reduced in both the working myocardium and conduction system of diabetic rat hearts. These results suggest that the changes in metabolic condition also exist in the conduction system of the diabetic rat hearts as well as the working myocardium.
Kuroda
A
A
First Department of Internal Medicine, Kagoshima University School of Medicine, Japan.
Saito
K
K
Tanaka
H
H
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D004734:Energy Metabolism / Q000502:physiology; D005947:Glucose / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D006329:Heart Conduction System / Q000378:metabolism* / Q000473:pathology* / Q000503:physiopathology; D006651:Histocytochemistry; D008297:Male; D009206:Myocardium / Q000201:enzymology / Q000473:pathology; D010732:Phosphofructokinase-1 / Q000378:metabolism; D011767:Pyruvate Decarboxylase / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013311:Streptozocin
D013311:Streptozocin; D005954:Glucosephosphate Dehydrogenase; D010732:Phosphofructokinase-1; D011767:Pyruvate Decarboxylase; D000254:Sodium-Potassium-Exchanging ATPase; D005947:Glucose