FLUOROMETRIC ANALYSIS OF AMIDASE AND ALKALINE PHOSPHATASE IN NEONATAL RAT THYMOCYTES: PEAK ACTIVITIES AT TWO DAYS OF AGE

摘要

Activities of four amidases and alkaline phosphatase were studied in lymphoid cells obtained from the thymuses of rats during the first twenty-one days of post natal life. Alkaline phosphatase activity increases rapidly from a value of 1.4 on day one to 24.4 (17 fold increase) on day two, and then declines steadily until day seven from which time there is a constant activity (3.5) through day twenty-one. Similar activity profiles obtain for leucyl, alanyl and phenylalanyl amidases showing maxima on day two of 26.2, 28.9 and 21.3 respectively. Comparatively constant activity levels are reached after one week, leucyl having the lowest value, 3.7, phenylalanyl slightly higher, 4.5 and alanyl the highest, 9.3. However, glycyl amidase activity is nil on day one, rises to a maximum activity of 12.4 on day two and then falls off again to an immeasurable quantity by day fourteen.nHistological examination of thymuses over the period studied revealed a relative increase in the number of large lymphoid cells at a time when enzyme activity was at a maximum and a relatively greater number of small lymphoid cells during the last two weeks when enzyme activity had reached a low steady level. The changes in enzyme activities observed in the present study appear to reflect changes in the large thymocyte population.