[Effect of potassium orotate and guanine on calcium uptake in small intestine of chickens with different amounts of vitamin D3].

Potassium orotate and guanine are established to accelerate the duodenum physiological response of chickens with experimental rachitis to administration of vitamin D3 in the in vivo experiments. They stumulate the uptake and transport of calcium, increase the content of calcium-binding protein and affect the activity of alkaline phosphatase. Guanine is a more effective stimulator as compared to orotate. A rise in the calcium uptake in the duodenum of the chicken which were given guanine started considerably earlier than the intensification of the calcium-binding protein synthesis in it. This suggests a possibility of the calcium uptake initiation by vitamin D3 through the mechanisims independent of the calcium-binding protein biosynthesis.