© 2006 The Japanese Biochemical Society.
Regular Paper |
Attenuation of Cardiac Hypertrophy in Carnitine-Deficient Juvenile Visceral Steatosis (JVS) Mice Achieved by Lowering Dietary Lipid
1 Department of Molecular Metabolism and Biochemical Genetics and 2 Laboratory for Neuroanatomy, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544; and 3 Department of Veterinary Physiology, Faculty of Agriculture, Kagoshima University, 1-21-24 Kohrimoto, Kagoshima 890-0065
* To whom correspondence should be addressed. Tel: +81-99-275-5242, Fax: +81-99-264-6274, E-mail: masakun{at}m.kufm.kagoshima-u.ac.jp
We examined the development of cardiac hypertrophy in juvenile visceral steatosis (JVS) mice, a model of systemic carnitine deficiency, by varying the amount of lipid in the diet. Cardiac hypertrophy was markedly attenuated by decreasing soy bean oil (SBO) from 5% (w/w) to 1%. Triglyceride contents of the ventricles of JVS mice fed 1% SBO were significantly lower than in JVS mice fed 5% SBO. The addition of medium-chain triglycerides metabolically utilized by JVS mice did not affect the development of cardiac hypertrophy. On the other hand, the mRNA levels of atrial natriuretic peptide and skeletal 
-actin, which are related to cardiac hypertrophy, were also attenuated by decreasing lipid in the diet. Adenylate energy charge and creatine phosphate in the heart of JVS mice at the early stage of hypertrophy were not significantly different from control mice given the same laboratory chow (4.6% of lipid). Although urinary prostaglandin F2 levels were found to be increased in JVS mice at 15 days of age when they developed cardiac hypertrophy, administration of aspirin was not efficacious. We, therefore, propose that the proportion of lipid in the diet is important in the development of cardiac hypertrophy in carnitine-deficient JVS mice, and that this is not related to prostaglandin formation.