Phenylhydrazine으로 처리한 토끼 적혈구의 Aspartate Aminotransferase Isozyme의 활성도 = Activity of Aspartate Aminotransferase Isoxymes in Red Blood Cells Obtained from Rabbit Treated with Phenylhydrazine

다국어 초록 (Multilingual Abstract)

The activity of aspartate aminotransferase(L-aspartate:2-oxoglutarate aminotransferase, EC 2.6.1.1) isozymes in red blood cells were studied during induction of and recovery from phenylhydrazineproduced reticulocytosis. Aspartate aminotransferase activity was assayed by calorimetric method of Reitman and Frankel. The results obtained were as follows:
1. Red blood cells of normal rabbit contained about 2.5%, of reticulocytes.
2. Total activity of aspartate aminotransferase in normal blood cells was 20.30 units and the relative activity of cytosolic and mitochondrial aspartate aminotransferase isozymes were 98.5% and 1.5%, respectively.
3. The reticulocyte count in phenylhydrazine-treated rabbit increased to a value of about 55%, on day 5, and attained a value of essentially 100% on day 6.
4. Total aspartate aminotransferase activity was maximal on day 7, about 49.85 units, which is about 2.46 fold higher than normal value. The relative activity of cytosolic and mitochondrial aspartate aminotransferase isozymes were 90.27% and 9.73%, respectively.
5. The increase in total aspartate aminotransferase activity during the induction of reticulocytosis was due primarily to the 16.17 fold increase in the activity of the mitochondrial isozyme (K_s=0.0325; K_d =O.0067; t(1/2)=103.43hr).
6. The activity of the cytosolic isozyme increased to about 2.4 times its normal value(K_s=0.8496;K_d=0.0177; t(1/2)=39.15hr).
7. The rate constants following recovery from phenylhydrazine treatment were: K_s=0.0132; K_d=0.0440; t(1/2)=15.75hr. for the mitochondrial isozyme and K_s=0.5340; K_d=0.0267; t(1/2)=25.96hr. for the cytosolic isozyme.