Stimulatory effect of 1,25-dihydroxyvitamin D3 on transferrin synthesis in primary cultures of adult rat hepatocytes.
The effect of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] on protein synthesis was studied in primary cultures of adult rat hepatocytes, in comparison with those of dexamethasone (DEX). The transferrin (TF) level in the culture medium assayed by a radioimmunoassay (RIA), after incubation for 24 hr was increased in the presence of 1,25-(OH)2D3, significantly at concentrations of more than 10(-12) M and maximally to about 140% of that in control cultures at 10(-8) M, without change in the albumin concentrations, assayed by an EIA. Other vitamin D3 metabolites had similar but weaker effects in increasing transferrin synthesis. On the other hand, incubation with 10(-6) M Dex for 24 hr enhanced the syntheses of both transferrin and albumin. Addition of 10(-7) M actinomycin D did not significantly block the effect of 1,25-(OH)2D3, but did suppress that of dexamethasone. These results indicate that 1,25-(OH)2D3 stimulates TF synthesis of cultured rat hepatocytes with different mechanism(s) of action from that of dexamethasone.
Taniguchi
K
K
Department of Geriatric Medicine, Osaka University Medical School, Japan.
Morimoto
S
S
Itoh
K
K
Morita
R
R
Fukuo
K
K
Imanaka
S
S
Ogihara
T
T
D000418:Albumins / Q000096:biosynthesis; D000818:Animals; D002117:Calcitriol / Q000494:pharmacology*; D002478:Cells, Cultured; D002762:Cholecalciferol / Q000378:metabolism; D003609:Dactinomycin / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D007124:Immunoenzyme Techniques; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D014168:Transferrin / Q000096:biosynthesis*
D000418:Albumins; D014168:Transferrin; D002762:Cholecalciferol; D003609:Dactinomycin; D003907:Dexamethasone; D002117:Calcitriol