抄録
The development of alkaline phosphatase influenced by 1α-OH-D3 (a synthetic active form of vitamin D3) and cortisone was studied in chick duodenal organ cultures. The administration of cortisone to the embryo in ovo on the 14th day of incubation resulted in a precocious increase in alkaline phosphatase after 6 days (20-day embryo). When duodena from 14-, 18- and 20-day embryos were cultured in the presence of cortisone, there was no significant enhancement of alkaline phosphatase activity except for a marginal effect observed in the 18-day duodenum. On the other hand, the alkaline phosphatase activity in cultured duodena from 20-day chick embryos was significantly stimulated by the addition of 1α-OH-D3. The effects of cortisone and 1α-OH-D3 were not additive. The activity of maltase, another intestinal enzyme, was not influenced by 1α-OH-D3. Studies on inactivation of alkaline phosphatase by EDTA suggest that the observed increase in alkaline phosphatase activity induced by the administration of 1α-OH-D3 in vitro may be related to the qualitative changes in the enzyme that take place during development in vivo.
