Dihydrotachysterol induction of intestinal calcium-binding activity in the chick
| Autor: | J.L. Omdahl, P.A. Thornton |
|---|---|
| Rok vydání: | 1972 |
| Předmět: |
Calcium Isotopes
Male Vitamin endocrine system medicine.medical_specialty Time Factors medicine.drug_class Antibiotics Stimulation Biochemistry Hydroxylation chemistry.chemical_compound In vivo Internal medicine polycyclic compounds medicine Vitamin D and neurology Animals Intestinal Mucosa Pharmacology Calcium metabolism Dose-Response Relationship Drug Proteins Intestines Endocrinology Animals Newborn chemistry Dactinomycin Dihydrotachysterol Calcium Chromatography Thin Layer Chickens hormones hormone substitutes and hormone antagonists Protein Binding medicine.drug |
| Zdroj: | Biochemical Pharmacology. 21:231-238 |
| ISSN: | 0006-2952 |
| Popis: | Appearance of the calcium-binding protein (CaBP) in intestinal mucosal preparations has previously been regarded as a vitamin D-dependent process. However, dihydrotachysterol, a compound stereo-chemically related to vitamin D, was found to be capable of inducing CaBP activity in vitamin D-deficient chicks. Dihydrotachysterol 2 (DHT 2 ) and dihydrotachysterol 3 (DHT 3 ) were less active than vitamin D 3 at lower dosage levels (i.e. up to 325 nmoles); while a high dose (i.e. 3.25 μmoles) of the sterols demonstrated activities equivalent to or surpassing that for vitamin D 3 . At the high dosage level, DHT 2 appeared more active than either DHT 3 or vitamin D 3 . Stimulation of calcium absorption was detectable at 5 hr and CaBP activity at 10 hr following DHT 2 repletion (325 nmoles), giving approximately the same time course of events as an equivalent dose of vitamin D 3 . Induction of CaBP activity was actinomycin sensitive, although the action of DHT 2 was not completely blocked by the antibiotic. Such action for DHT in the intestine was discussed in view of possible hydroxylation in vivo at C-25, similar to vitamin D. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|