25-hydroxylation of vitamin D3 in rat liver: roles of mitochondrial and microsomal cytochrome P-450.
A mitochondrial cytochrome P-450 fraction, which catalyzed 25-hydroxylation of vitamin D3 much more efficiently than intact mitochondria was isolated from livers of male and female rats. For comparison, a microsomal cytochrome P-450 fraction was isolated by the same procedures. The mitochondrial cytochrome P-450 from female rats catalyzed 25-hydroxylation as efficiently as the same material from male rats. The microsomal 25-hydroxylation was male specific. The 25-hydroxylase activity in intact mitochondria and the 25-hydroxyvitamin D3 concentration in serum were similar in male and female rats. There was no correlation between the 25-hydroxylase activity in microsomal cytochrome P-450 and the 25-hydroxyvitamin D3 concentration in serum.
D000818:Animals; D002112:Calcifediol / Q000097:blood / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005260:Female; D006900:Hydroxylation; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D012727:Sex Characteristics
D003577:Cytochrome P-450 Enzyme System; D002112:Calcifediol