Isoenzymes of alkaline phosphatase in serum of newly born lambs.

In the serum of lambs at birth most of the circulating alkaline phosphatase, identified by electrophoretic analysis, was of skeletal origin. Suckling was associated with a rapid increase in activity of intestinal alkaline phosphatase isoenzymes in serum. There was a coincidental increase in level of circulating gamma globulin. Activity of the intestinal isoenzymes in serum began to fall between 15 and 21 h after birth and this fall preceded a fall in serum gamma globulin concentration. The electrophoretic characteristics of the intestinal isoenzymes in serum changed as activity of these isoenzymes increased and then decreased.