The appearance of 1,25-dihydroxyvitamin D3 receptor during chick embryo development

The appearance of the 1,25-dihydroxyvitamin D3 receptor in intestine, kidney, and chorioallantoic membrane of chick embryo was followed by sucrose density gradient sedimentation analysis and Scatchard plot analysis. The receptor from each of these organs sediments as a single 3.7S component. At 19 days of embryonic life, intestine had the highest specific 1,25-dihydroxyvitamin D3 binding activity followed by kidney and chorioallantoic membrane. The 1,25-dihydroxyvitamin D3 binding activity increased gradually at 12-15 days and rapidly until 20 days in intestine. In kidney, this protein increased rapidly from 12 to 16 days and did not change subsequently. In chorioallantoic membrane, the receptor increased slowly from 8 through 15 days, rapidly until 19 days, and decreased at 20 days. The injection of hydrocortisone into the chick embryo at 10 days increased receptor number in intestine, kidney, and chorioallantoic membrane by a factor of 2 at 12 days. Injection of this hormone after this time had little or no effect.