Abstract
The effect of 1α-hydroxyvitamin D3 (1αOHD3) on the renal clearance of creatinine was investigated in groups of rabbits with stable renal insufficiency and normal controls. Urine was collected in the two groups for two one-week periods during placebo treatment. Then, 1αOHD3, 0.02 μg/kg BW/day, was adminstered orally and urine was collected during the next two weeks. Weekly blood samples were obtained. The treatment had no significant effect on the serum concentrations of calcium and phosphate in either group. Creatinine clearance decreased significantly in both groups during the 1αOHD3 treatment (p<0.05), mainly due to a decreased urinary excretion of creatinine. It is suggested that changes in the renal tubular handling of creatinine caused by 1αOHD3 may be the explanation of the observed effect.