Vitamin D 3 -Induced Calcium-Binding Protein in Chick Intestinal Mucosa
1966; American Association for the Advancement of Science; Volume: 152; Issue: 3723 Linguagem: Inglês
10.1126/science.152.3723.791
ISSN1095-9203
Autores Tópico(s)Animal Nutrition and Physiology
ResumoThe administration of vita-min D(3) to rachitic chicks induces in intestinal mucosal tissue the formation or elaboration of a calcium-binding factor which is found in the supernatant of the mucosal homogenate. The enhanced binding of Ca by the "vitanmin D" supernatant (in contrast to "rachitic" supernatant) was indicated by a slower rate of diffusion of Ca(45) across a cellophane dialyzing membrane and by a lesser amount of Ca(45) being bound to an ion-exchange resin (Chelex-100) in the presence of vitamiiin D(3) supernatant. The binding activity was only associated with the protein fraction from a Sephadex G-25 column and was destroyed by trypsin digestion. This and other evidence suggest that the soluble factor is a protein. The vitamin D(3)-enhanced duodenal absorption of Ca(47) in rachitic chicks occurred almost simultaneously with the appearance of the vitamin D(3)-induced factor, and there was good correlation between the concentration of binding factor and the rate of absorption of Ca(47).
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