Vitamin D Metabolism and Parathyroid Function in Man
| Autor: | L. F. Hill, G. A. Lumb, Priyadarshini de Silva, Joan Backhouse, S. W. Stanbury, E. Barbara Mawer, Carol M. Taylor |
|---|---|
| Rok vydání: | 1975 |
| Předmět: |
Adult
Male medicine.medical_specialty Biopsy Osteitis Fibrosa Cystica Radioimmunoassay Parathyroid hormone chemistry.chemical_element Calcium Bone and Bones vitamin D deficiency Parathyroid Glands Radioligand Assay chemistry.chemical_compound Internal medicine medicine Vitamin D and neurology Humans Aged Cholecalciferol Chemistry General Medicine Metabolism Middle Aged Alkaline Phosphatase medicine.disease Endocrinology Parathyroid Hormone Creatinine Dihydroxycholecalciferols Female Primary hyperparathyroidism Hormone |
| Zdroj: | Clinical Science. 48:349-365 |
| ISSN: | 0301-0538 |
| Popis: | 1. The metabolism of an intravenous pulse dose of double-isotope-labelled cholecalciferol has been studied in control subjects with widely differing states of vitamin D nutrition and in patients with primary disorders of parathyroid function. 2. The formation of labelled 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] and labelled 24,25-dihydroxycholecalciferol [24,25-(OH)2D3] has been related to the prevailing concentrations in serum of 25-hydroxycholecalciferol [25-(OH)D3], immunoreactive parathyroid hormonel, calcium and orthophosphate (Pi). 3. In control subjects with relative vitamin D deficiency [serum 25-(OH)D3 4. No control subject produced significant amounts of both labelled 1,25-(OH)2D3 and labelled 24,25-(OH)2D3 simultaneously. 5. All subjects with primary hyperparathyroidism produced significant amounts of labelled 1,25-(OH)2D3 and labelled 24,25-(OH)2D3 simultaneously; the renal turnover of 25-(OH)D3 was apparently greater than in nutritionally matched controls. Serum labelled 1,25-(OH)2D3 in this disease was not correlated with serum 25-(OH)D3, immuno-reactive parathyroid hormone, calcium or Pi. Production of labelled 24,25-(OH)2D3 was inappropriately high for the prevailing nutritional state. 6. The indirectly estimated molar concentration of 1,25-(OH)2D3 showed only a fourfold variation in control subjects (45-180 pmol/l), compatible with its having a regulated hormonal function. 7. The data suggest that the production of 1,25-(OH)2D3 from a pulse dose of cholecalciferol is normally regulated, directly or indirectly, by the parathyroid hormone. |
| Databáze: | OpenAIRE |
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