Carbonic anhydrase activity in blood of early sheep fetuses

Abstract

1. 1. The level of carbonic anhydrase activity in the red cells was measured in sheep fetuses at different times after conception: 39, 56, 77, 90 and 140 days, the last being close to full term. Measurements were also made on blood from four of the mothers. 2. 2. There was a low level of the enzyme present in the 39 day fetuses (0.037 enzyme units (E.U.)/100 μg Hb) and its increase up to 90 days of gestation (0.19 E.U./100 μg Hb) had a form approximating exponential. 3. 3. The earliest levels were only 11% of the full term levels and only 4% of the adult levels previously reported. 4. 4. Even the earliest samples were of blood that was fetal rather than embryonic but these results are the earliest carbonic anhydrase activities reported in this mammal.