정상토끼의 적혈구와 phenylhydrazine을 주사한 후 시간이 경과하는 동안에 채혈한 혈액 의 적혈구에서 alanine aminotransferase (L-alanine: 2-oxoglutarate aminotransferase, EC 2.6.1.2)의 총 활성도의 변화와 세포질 및 mitochondria에 있는 AAT isozyme의 pattern을 관찰하여 다음과 같은 결론을 얻었다. 1. 정상토끼 적혈구의 망상적혈구수는 약 2.5%이었으며 phenylhydrazine을 주사한 후 심한 망상적혈구중다중이 유발된 5일에 약 75%, 7일에 100%가 되었다. 2. 정상토끼 적혈구에서 alanine aminotransferase의 총 활성도는 13.20 unit이었으며 세포장파 mitochondria 분획에 AAT isozyme이 98.5% 및 1.5%가 각각 함유되어 있다. 3. 망상적혈구중다중에 걸린 토끼적혈구의 총 AAT활성도는 정상토끼의 적혈구에 비하여 약 1.82배 증가된 24.05 unit이었으며 세포질 및 mitochondria에 65.24% 및 34.76%가 각각 함유되어 있었다. 4. 망상적혈구중다중이 유발되는 동안 총 AAT 활성도의 중가는 mitochondria 에 있는 AAT isozyme의 활성도가 정상토끼에 비하여 약 41.8배 증가되었기 때문이다($K_s=0.1112$ : $K_d=0.0133$ : $t{frac{1}{2}}=52;hr$). 5. 세포질에 있는 AAT isozyme의 활성도는 정상토끼에 비하여 약 1.23배 증가되었다($K_s=0.3040$ : $K_d=0.0190$ : $t{frac{1}{2}}=36.5;hr$). 6. Phenylhydrazine을 처리한 후 회복기에 있어서 AAT합성 및 분해속도상수는 다음과 같다. Mitochondria의 AAT isozyme : $K_s=0.0054$ : $K_d=0.0268$ : $t{frac{1}{2}}=26;hr$, 세포질외 AAT isozyme: $K_s=0.0793$ : $K_d=0.0061$ : $t{frac{1}{2}}=115;hr$이었다.
In order to establish a general pattern of synthesis and break-down of cytosolic and mitochondrial alanine aminotransferase (L-alanine: 2-oxoglutarate aminotransferase, EC 2.6.1.2) isozymes in normal and reticulocytic red blood cells of domestic rabbits, sequential measurements of total and relative activities of AAT isozymes in the red blood cells of normal and phenylhydrazine treated rabbits were conducted in this study. The results and summarized as follows: 1. The reticulocyte count of normal rabbit blood was approximately 2.5%, and the administration of phenylhydrazine resulted in rapid and profound reticulocytosis, i.e., about 75% on day 5 and essentially 100% on day 7. 2. Total activity of alanine aminotransferase in normal blood cells was 13.20 units and the relative activities of cytosolic and mitochondrial alanine aminotransferase isozymes were 88.5% and 1.5%, respectively. 3. In phenylhydrazine-treated rabbits, total alanine aminotransferase activity was maximal on day 6, about 24.05 units, which is about 1.82 fold higher than normal value. The relative activities of cytosolic and mitochondrial alanine aminotransferase isozymes were 65.24% and 34.76%, respectively. 4. The increase in total alanine aminotransferase activity during the induction of reticulocytosis appeared to be due primarily to the 41.g-fold increase in the activity of the mitochondria) isozymes ($K_s=0.1112$; $K_d=0.0133$; $t{frac{1}{2}}=52;hr$). 5. The activity of the cytosolic isozyme in phenylhydrazine-treated rabbit red blood cells increased to about 1.23 times its normal value ($K_s=0.3040$; $K_d=0.0190$; $t{frac{1}{2}}=36.5;hr$). 6. The rate constants following recovery from phenylhydrazine treatment were: $K_s=0.0054$; $K_d=0.0268$; $t{frac{1}{2}}=26;hr$. for the mitochondrial isozyme and $K_s=0.0793$; $K_d=0.0061$; $t{frac{1}{2}}=115;hr$. for the cytosolic isozyme.
