Effect of 24, 25-dihydroxycholecalciferol on the placental immunoreactive
by Georg B¸hler, Svetla Balabanova & Julian Rosenthal
GH; GH-RH; estradiol; progesterone
OBJECTIVES: Calcitonin (CT) has a regulative function in calcium
(Ca) transfer from mother to the fetus. There are indications
that cholecalciferol can play a role in this process. With this
background, the effect of 24, 25-dihydroxycholecalciferol (24,
25-DHC) on immunoreactive CT by human placenta at term was studied
Placental tissue samples were incubated in culture medium with
normal total Ca (1.3 mM) concentrations during 6 hours at 37C.
24, 25-DHC was added to the samples.
Addition of 24, 25-DHC in concentrations of 25, 75 and 150 pg/ml
was followed by a significant decrease of CT levels in medium.
The concentrations decreased from 100% (basis value after 2
hours) to 31%, 46% and 49% respectively.
Probably 24, 25-DHC has a modulating effect on the regulation
of placental Ca transfer by CT.