title: Pharmacokinetic study of 45Ca administered intravenously following intramuscular injection of vitamin D3 or 25-hydroxyvitamin D3 in early weaned lambs.
abstract: The objective of this study was to evaluate the pharmacokinetic parameters of 45Ca administered intravenously at a dose of 50 microCi in young lambs. The experiment was performed on 18 female lambs allocated to three treatments. Six animals received intravenous calcium only; six received intramuscularly vitamin D3 8 days prior to the administration of calcium; and six received intramuscularly 25-hydroxyvitamin D3 5 days prior to the administration of calcium. Blood samples were collected from 15 min up to 8 days after the administration of 45Ca. The different pharmacokinetic parameters (area under the curve, clearance, mean residence time and volume of distribution) were estimated using non-compartmental and compartmental approaches. Statistical analysis of the results showed no significant differences in the pharmacokinetic parameters of the three groups. It can be concluded that vitamin D does not modify either the elimination or the distribution of calcium in the lambs receiving adequate dietary vitamin D.
mesh_terms: D000818:Animals; D002112:Calcifediol / Q000008:administration & dosage*; D002118:Calcium / Q000008:administration & dosage* / Q000097:blood / Q000378:metabolism*; D002132:Calcium Radioisotopes; D002762:Cholecalciferol / Q000008:administration & dosage*; D004347:Drug Interactions; D005260:Female; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D012756:Sheep / Q000378:metabolism*