O. Kozawa et al., MODULATION OF PROSTAGLANDIN E(2)-INDUCED CA2-HORMONES IN OSTEOBLAST-LIKE CELLS( INFLUX BY STEROID), Prostaglandins, leukotrienes and essential fatty acids, 49(3), 1993, pp. 711-714
In osteoblast-like MC3T3-E1 cells, eve previously reported that prosta
glandin E(2) (PGE(2)), a potent bone resorbing agent, stimulates Ca2influx (H. Tokuda, M. Miwa, Y. Oiso and O. Kozawa, Cell Signal 1992; 4
: 261-266). In this study, we examined the effects of various hormones
belonging to the steroid hormone superfamily on PGE(2) -induced Ca2influx in MC3T-E1 cells. 1,25-Dihydroxyvitamin D-3 1,25-(OH)(2)D-3,
an active form of vitamin D-3, dexamethasone and retinoic acid signifi
cantly inhibited the PGE(2)-induced Ca2+ influx in a dose-dependent ma
nner in these cells. The effects of these hormones were dependent on t
he time of pretreatment and submaximum inhibitions were observed at 6
h. In contrast, 24,25-dihydroxyvitamin D-3 24,25-(OH)(2)D-3, an inac
tive form of vitamin D-3, 17 beta-estradiol, progesterone, testosteron
e and triiodothyronine had little effect on the PGE(2)-induced Ca2+ in
flux in these cells. These results suggest that, in the steroid hormon
e superfamily, 1,25-dihydroxyvitamin D-3, glucocorticoid and retinoic
acid modulate bone metabolism through the inhibition of Ca2+ influx in
duced by PGE(2) in osteoblast-like cells.