Effect of Long-Term Pyridoxine Depletion on Asparte Aminotransferase and Pyridoxal 5'-Phosphate of Rat Liver Mitochondrial and Cytosolic Fractions

장기간의 Pyridoxine 부족이 쥐 간의 Mitochondria 및 Cytosolic Fraction 에 있는 Aspartate Aminotransferase 및 Pyridoxal 5'- Phoshate에 미치는 영향

Weanling female Sprague Dawley rats were fed d diets containing 22mg pyridoxine. BCI/kg diet (control diet) and l.2mg pyridoxine. BCI/kg diet (deficient diet). One control group and one defi­c dent group were fed their diet throughout growth, g gestation and lactation. After the pups were born and weaned, the deficient group was divided into two groups. One switched to control diet(supple­I mented group) and the other continued the same d deficient diet( deficient group) until 10 week -old. The liver mitochondrial and cytosolic asparate a aminotransferase activity and pyridoxal phosphate content were determined in offspring rats. The aspartate aminotransferase activities in both liver mito$\phi$ondrial and cytosolic fractions of den­d cient group were significantly lower than those of controls, but there were no significant differences between two groups after addition of 1O^{-4}M pyri­d do뼈I phosphate to the medium. By pyridoxine s supplementation after weaning, the reduced aspar­a tate aminotnmsferase activities were only partialy I restored to control levels. The pyridoxal phospha­t te content of deficient group in Iiver mitochondr­ial and cytosoIic fractions were alo significantly different from those of controls, but readily restored by dietary supplementation. These results suggest that there is a quantitative and a qualitative changes of aspartate amino trans­f ferase and pyridoxal phosphate in liver mitochon­d drial and cytosolic fraction by long-term pyrido­x xine deficiency and these reductions can partially recovered by dietary pyridoxine supplementation after weaning.

이유한 Sprague Dawley 종의 암컷 흰쥐를 두군으로 나누어 각각 pyridoxine이 충분한 식이 (22mg/kg diet)와 pyridoxine이 부족한 식이 (1.2mg/kg diet0로 성장시킨후, 적절한 시기에 임신시켰다. 태어난 새끼가 이유할 때 결핍식이군을 둘로 나누어, 한쪽은 pyridoxine이 충분한 식이로 바꾸어준후, 세군의 쥐를 생후 10-주까지 성장시켰다. 각 군의 새끼쥐가 각각 0, 3, 7, 10 주 되었을대, 간의 mitochondria 및 cytosolic fraction 에 있는 Asparate aminotransferase [ EC 2.6.1.1] activity 및 pyridoxal phosphate의 함량을 측정하였다. 결핍군의 간 aspartate aminotransterase activity는 mitochondria 및 cytosolic fraction에서 각각 대조군에 비해 유의적으로 낮았으며 10-4 M pyridoxal phosphate를 첨가한 후 측정한 total enzyme activity 는 거의 대조군과 비슷하였다. 3 주이후 pyridoxine 이 충분한 식이로 바구어준 회복군에서도 대조군에 비해 유의적으로 낮았으나, 결핍군보다는 높았다. 이두 fraction 에서의 pyridoxal phosphate 함량은 결핍군이 대조군보다 현저히 낮았으며, 회복군은 대조군과 비슷하였다. 이로써, 장기간에 걸친 pyridoxine결핍이간의 aspartate aminotransferase activity 및 pyridoxal phosphate에 현저한 영향을 미치며 이유기 이후의 식이보충에 의해서도 enzyme activity는 쉽게 회복되지 않음을 알 수있다.