Myofibrillar, mitochondrial and valvular morphological alterations in cardiac hypertrophy among copper-deficient rats.
Histological aspects of Cu-deficient hypertrophied rat hearts were evaluated to determine causal factors. Twenty-four male weanling rats were fed either Cu-adequate (8.0 mg/kg diet) or Cu-deficient (0.4 mg/kg diet) diets until 9 or 11 wk of age. Copper-deficient rats had increased mitochondrial:myofibrillar ratios compared with Cu-adequate rats. Mitochondria were vacuolated. Cristae seemed fragmented and matrix seemed translucent and they tended to distort the myofibrils. Glycogen granules and lipid droplets were more frequently observed in Cu-deficient rats. When the Cu-deficient rats were examined separately, the larger hearts in the older rats had smaller mitochondrial:myofibrillar ratios, but had larger myofibrillar volume densities. Valves from Cu-deficient rats had less connective tissue and seemed fragmented in areas. In 9-wk-old Cu-deficient rats, there was a negative correlation between heart: body weight ratios and bicuspid valve scores, whereas 11-wk-old rats demonstrated the same relationship for tricuspid valves with myofibril volume density. These results suggest that there are two components contributing to cardiac hypertrophy in copper deficient rats: 1) an enlarged mitochondrial area and 2) myofibrillar enlargement. Hematocrit values did not seem to be related to cardiac hypertrophy.
Medeiros
D M
DM
Department of Human Nutrition and Food Management, Ohio State University, Columbus 43210.
Bagby
D
D
Ovecka
G
G
McCormick
R
R
D000818:Animals; D006332:Cardiomegaly / Q000150:complications / Q000473:pathology*; D003300:Copper / Q000172:deficiency*; D006400:Hematocrit; D008297:Male; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure*; D008943:Mitral Valve / Q000378:metabolism / Q000648:ultrastructure*; D009210:Myofibrils / Q000378:metabolism / Q000648:ultrastructure*; D051381:Rats; D011919:Rats, Inbred Strains; D014261:Tricuspid Valve / Q000378:metabolism / Q000648:ultrastructure*
D003300:Copper