Metabolism and excretion of 3H-1,25-(OH)2-vitamin D3 in healthy adults.
J Clin Endocrinol Metab
; 46(5): 756-65, 1978 May.
Article
en En
| MEDLINE
| ID: mdl-263717
The synthesis of very high specific activity 25-OH-vitamin D3 (78 Ci/mmol) has made possible the study of the metabolism and plasma disappearance of 3H after a single dose of 3H-1,25-(OH)2-D3 in quantities that are only 10-20% of the endogenous plasma pool. We studied seven healthy adults who were given doses of 1,25-(OH)2-D3 ranging from 30-2300 pmol. Plasma disappearance was rapid with only 14 +/- 2% of administered 3H remaining in the plasma pool 4 h after labeling. Plasma metabolite profiles during the first 4 h showed only 1,25-(OH)2-D3. Thereafter, significant amounts of other metabolites were detected. The 6-day cumulative excretion of 3H in urine and feces (virtually all associated with metabolites of 1,25-(OH)2-D3) averaged 16 +/- 3% and 49 +/- 11% of the dose, respectively. Compartmental analysis of the isotope data for two subjects who received the smallest doses of 1,25-(OH)2-D3 indicated that endogenous renal 1,25-(OH)2-D3 synthesis rates approximate 0.8-2.4 nmol/day (0.3-1.0 microgram/day).
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Bases de datos:
MEDLINE
Asunto principal:
Calcitriol
Límite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
J Clin Endocrinol Metab
Año:
1978
Tipo del documento:
Article