25-hydroxycholecalciferol 1 alpha-hydroxylase activity in the kidney of the fetal, neonatal and adult guinea pig.
Homogenates of fetal, newborn and maternal kidney and placenta have been compared with homogenates of non-pregnant adult kidney for their ability to hydroxylate 25-hydroxycholecalciferol. The activity in the fetal kidney near term is similar to that in the mother and 4--5 times that in the non-pregnant adult. These differences from the non-pregnant adult are significant (p less than 0.05 and 0.1 fetus and newborn, respectively). Even higher levels are present in some newborn 12--24 h after birth, but these values fall towards the non-pregnant level in the following 21 days. Significant hydroxylating activity is present in the near-term placenta.
D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D005260:Female; D005333:Fetus; D006168:Guinea Pigs; D007668:Kidney / Q000201:enzymology / Q000254:growth & development*; D008297:Male; D011247:Pregnancy; D013250:Steroid Hydroxylases / Q000378:metabolism*
D013250:Steroid Hydroxylases; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase