title: The relationship between fibrosis and lactate dehydrogenase isoenzymes in the experimental hypertrophic heart of rabbits.
abstract: Cardiac hypertrophy was induced in rabbits by injecting either thyroxine or isoprenaline or by surgically constricting the abdominal aorta. An increase in heart weight was associated with a change in the lactate dehydrogenase isoenzyme pattern and an increase in fibrosis (as measured by hydroxyproline concentrations). Isoprenaline treatment led to a moderate increase in heart weight, a marked decrease in the heart/skeletal muscle subunit ratio of lactate dehydrogenase, and a marked increase in hydroxyproline. Thyroxine treatment led to a small increase in both heart weight and hydroxyproline and a small decrease in the heart/skeletal muscle subunit ration. Coarctation of the aorta, in contrast, caused a marked increase in heart weight, a moderate decrease in heart/skeletal muscle subunit ratio, and a moderate increase in hydroxyproline. These results suggest that the decrease in the heart/skeletal muscle subunit ratio of lactate dehydrogenase in the experimental hypertrophic heart reflects the extent of myocardial fibrosis, rather than changes within the hypertrophied myocardial cells.
mesh_terms: D000818:Animals; D001017:Aortic Coarctation / Q000150:complications; D006332:Cardiomegaly / Q000201:enzymology* / Q000209:etiology / Q000473:pathology; D003094:Collagen / Q000032:analysis; D006909:Hydroxyproline / Q000032:analysis; D007527:Isoenzymes; D007545:Isoproterenol; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D008297:Male; D009336:Necrosis; D011817:Rabbits; D013974:Thyroxine
chemical_list: D007527:Isoenzymes; D003094:Collagen; D007770:L-Lactate Dehydrogenase; D007545:Isoproterenol; D013974:Thyroxine; D006909:Hydroxyproline