| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1990: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1989: ¥1,000,000 (Direct Cost: ¥1,000,000)
|
|---|
| Research Abstract |
Calcium oxalate comprises more than two-thirds of all urinary tract stones in Japan. However, its pathogenesis has not been fully clarified to date. Oxalate is reportedly considered to play a more important role than calcium in calcium oxalate stone formation, so that investigation of oxalate metabolism is mandatory. In considering oxalate metabolism, absorption from the intestine and renal handling of oxalate in the tubules, as well as its metabolism in the liver, are the major concerns. In order to elucidate the characteristics of oxalate transport across the rat brush border membrane, oxalate uptake and efflux by renal cortical brush border membrane vesicles were measured with great complexity, limiting its clinical use.
Baggio et al. (New Engl J Med 314:599-604, 1986) reported an inheritable anomaly of red-cell oxalate transport in primary calcium nephrolithiasis patients, suggesting that abnormal transmembrane oxalate flux in red cells may represent abnormal transport through the intestinal and renal tubular cell membrane. We have conducted an experiment according to his method, but we could not obtain consistent data, because the reaction was too fast and the conditions of red-cell preservation had influenced the results substantially. And moreover, the experiment had to be done under the temperature of zero centigrade, in which condition functions of the carrier-protein of oxalate might have been impaired. We have also tried to analyze oxalate transport using ghost cell of red blood cells in order to exclude the possible interference from various substances in erythrocytes. However, consistent data could not be obtained to our disappointment.
|
