The effect of parathyroid hormone and vitamin D3 metabolites on CaBP synthesis by embryonic duodenum, in vitro

Abstract

Embryonic chick duodena were incubated, in vitro, for two days in the presence of vitamin D analogues and metabolites and the ability of PTH to potentiate the vitamin-D-dependent synthesis of CaBP measured. PTH potentiated CaBP synthesis in the presence of vitamin D3, 25-OH-D3, 1 alpha-OH-D3, DHT, and 1,25(OH)2D3. The synthesis of CaBP was directly related to the log of the meddium PTH concentration over the range 1 x 10(-8) M to 5 x 10(-7) M.