1. Stimulation of 25-hydroxyvitamin D3-1alpha-hydroxylase by phosphate depletion.
- Author
-
Baxter LA and DeLuca HF
- Subjects
- Animals, Calcium metabolism, Chickens, Diet, Intestinal Mucosa metabolism, Kidney metabolism, Male, Phosphates metabolism, 25-Hydroxyvitamin D3 1-alpha-Hydroxylase metabolism, Phosphates deficiency, Steroid Hydroxylases metabolism
- Abstract
The ability of low phosphorus diets to stimulate the activity of the 25-hydroxyvitamin D3-1alpha-hydroxylase was tested in the chick. Feeding low phosphorus diets for 2 weeks resulted in a marked increase in enzyme activity relative to chicks fed a normal phosphorus diet. Stimulation of the 25-hydroxyvitamin D3-1alpha-hydroxylase activity by low phosphorus diets, however, was not as great as that observed with a low calcium diet. The low phosphorus and low calcium diets probably results from increased 1,25-dihydroxyvitamin D3 synthesis, whereas the stimulation by phosphate deprivation is only partly the result of increased 1,25-dihydroxyvitamin D3 production.
- Published
- 1976