Requirement for the heart-type fatty acid binding protein in cardiac fatty acid utilization

Nonenzymatic cytosolic fatty acid binding proteins (FABPs) are abundantly expressed in many animal tissues with high rates of fatty acid metabolism. No physiological role has been demonstrated for any FABP, although these proteins have been implicated in transport of free long-chain fatty acids (LCFAs) and protection against LCFA toxicity. We report here that mice lacking heart-type FABP (H-FABP) exhibit a severe defect of peripheral (nonhepatic, non-fat) LCFA utilization. In these mice, the heart is unable to efficiently take up plasma LCFAs, which are normally its main fuel, and switches to glucose usage. Altered plasma levels of LCFAs, glucose, lactate and beta-hydroxybutyrate are consistent with depressed peripheral LCFA utilization, intensified carbohydrate usage, and increased hepatic LCFA oxidation; these changes are most pronounced under conditions favoring LCFA oxidation. H-FABP deficiency is only incompletely compensated, however, causing acute exercise intolerance and, at old age, a localized cardiac hypertrophy. These data establish a requirement for H-FABP in cardiac intracellular lipid transport and fuel selection and a major role in metabolic homeostasis. This new animal model should be particularly useful for investigating the significance of peripheral LCFA utilization for heart function, insulin sensitivity, and blood pressure

停留精巣の研究 第3報: 停留精巣患者における精巣内複合糖質の組織化学的研究

3～37歳の停留精巣患者23例の停留精巣および対側陰嚢内精巣において, 光顕組織化学的方法にて複合糖質の変化を観察し, さらに正常精巣組織と比較した.停留精巣精細管壁及び間質では, 正常精巣に比べ酸性ムコ多糖(精細管壁:コンドロイチン硫酸A及びC, 間質:コンドロイチン硫酸B)が減少し, 特に精細管壁において顕著であった.なお, 患側精細管上皮においては, 思春期前から思春期以後を通じ, グリコーゲン及びガラクトース含有量の減少が認められたThe complex carbohydrates in the undescended and contralateral scrotal testes of patients with cryptorchidism, were examined by light microscopic histochemical methods, in comparison with those of normal testes. In the undescended testes, histochemical reactions for acidic and neutral complex carbohydrates were apparently weaker than in the normal testes, especially pronounced in the seminiferous tubular walls. In the germinal and supporting cells of the undescended testes, the amount of galactose residues in the complex carbohydrates decreased from the prepubertal to post-pubertal periods. Periodic acid-Schiff reaction also revealed a decrease in the glycogen content in the germinal and supporting cells of the undescended testes from pre-pubertal to post-pubertal periods