All issues > Volume 15(6); 1972
- Original Article
- J Korean Pediatr Soc. 1972;15(6):506-519. Published online June 30, 1972.
- Studies on the Difference of RNase Activity and Sialic Acid Level between Maternal and Fetal Serum and on Age Variation of RNase Activity
- Yong IL Lee1
- 1Department of Pediatrics, College of Medicine, Seoul National University
- Abstract
- The alkaline RNase activity and sialic acid level were determined and compared in maternal and fetal
serum. It was surveyed on the variation of serum alkaline RNase activity of human with age ranging from
birth to sixties, and also examined on its change of rat serum with age ranging from the 15th day of
life to 2 years. The acid and alkaline RNase activity was simultaneously investigated in rat spleen in terms of age
variation. The rusults obtained are as follows:
1) The serum alkaline RNase activity in 30 maternal and fetal pairs are 23. 9±5. 2 and 30. 4±5. 4respectively.
Thus the fetal value is higher than the maternal one with significance (p<0. 05).
2) The serum sialic acid level in 8 maternal and fetal pairs are 213. 3+35. 4 mg/dl and 85. 0±21. 6mg/dl, respectively. In contrast to alkaline RNase activity, its maternal level is 2. 5 times as much as the fetal one.
Since the RNase inhibitor was suggested to be a kind of glycoprotein, it was discussed on the
differences of alkaline RNase activity and sialic acid level between maternal and fetal serum in terms
of RNase inhibitor of glycoprotein. 3) The age variation of alkaline RNase activity in human serum is as follows.
The serum alkaline RNase activity is 30. 4±5. 4 at birth and 28. 8+3.1 at 2 years of age, but it
increases sharply from the age of 3 to maximum level of 47. 5±6. 5 at the age of 5 years.
It drops gradually, however, from the age of 6 to reach minimum level of 18. 9±2. 5 at around the
age of 29, and it increases thereafter steadily with age.
4) The alkaline RNase activity of rat serum is shown to be similar to the human pattern in terms
of age variation. The alkaline RNase activity drops gradually from the peak of 32. 4±2. 5 at one month of age to
the minimum level of 14. 4±1. 8 at the age of 5 month, but it is followed by its marked rise paralleling with age. The rise in serum RNase activity of the rat is much more remarkable in old age as compared to the human.
5) The acid and alkaline RNase activity of the rat spleen follows the same pattern of its serum,
demonstrating the marked increase in old age. The higher activity of splenic acid RNase is thought to be ascribed to very rich source of phagocytic cells in spleen.
6) The content of RNA-P and DNA-P in rat spleen is shown to decrease gradually with age.
Keywords :