| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1989: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1988: ¥1,200,000 (Direct Cost: ¥1,200,000)
|
|---|
| Research Abstract |
Congenital lactic acidosis of childhood is characterized by persistently high levels of blood pyruvate and lactate. In Japan, the number of reported cases of congenital tactic acidosis is increasing. However, in many patients with congenital lactic acidosis, the underlying deficiency cannot be found and most patients die in infancy or show growth and psychomotor retardation because no adequate treatment is available.
Therefore, we have been trying to develop a method for screening the disorders of pyruvate metabolism in cultured skin fibroblasts from patients with congenital lactic acidosis.
We developed an assay method for measuring lactate formation from (1-^<14>C)pyruvate in cultured skin fibroblasts. By the method, we measured the rates of lactate formation from (1-^<14>C) pyruvate and decarboxylktion of (1-^<14>C) pyruvate in cultured skin fibroblasts from patients with pyruvate dehydrogenase (PDH) deficiency (1), defect of PDH activation (3). defect of mitochondrial pyruvate transport (1), multiple carboxylase deficiency (1). complex I deficiency (1), complex IV deficiency (1), congenital tactic acidosis of unknown cause (10) and 16 control subjects (Numbers of cell lines are shown in parentheses). The rates of lactate formation and decarboxylation in fibroblasts from the patients were lower than those in control fibroblasts, by the upper values for the these patients overlapped the lower values for control subjects. In contrast, the ratio of lactate formation and pyruvate decarboxylation (L/D ratio) of these patients did not overlap those of controls and we could clearly distinguish the patients from control subjects.
Thus, measurement of L/D ratio is useful as a method for screening disorders of pyruvate metabolism in cultured skin :Bibroblasts. Using this mi-Bthod, we also found disorders of pyruvate metabolism in two of ten patients with congenital tactic acidosis of an unknown cause.
|
