Effect of estrogen and 1α,25(OH)2-vitamin D3 on the activity and growth of human primary osteoblast-like cells in vitro

Objective: To evaluate effects of 17beta-E-2 and 1alpha,25(OH)(2)-vitamin D-3 on human osteoblast-like (hOB) cells. Design: Controlled, experimental study. Setting: University hospital. Patient(s): hOB cell cultures were prepared from the upper femur of postmenopausal patients undergoing bipolar endoprosthesis arthroplasty for a fractured femoral neck. Intervention(s): hOB cells were subcultured with either 17beta-E-2 or 1alpha,25(OH)(2)-vitamin D-3, or both. Main Outcome Measure(s): Cell proliferation and activity of alkaline phosphatase, osteocalcin, and interleukin-6. Result(s): 17beta-E-2 significantly reduced interleukin-6 and osteocalcin to 34% and 60% of control value but induced alkaline phosphatase and cell proliferation to 183% and 150% of control value. 1alpha,25(OH)(2)-vitamin D-3 significantly decreased cell proliferation to 88% of that of control group, but 1alpha,25(OH)(2)-vitamin D-3 Plus 17beta-E-2 showed no difference from the control group. Alkaline phosphatase and osteocalcin were significantly increased by 1alpha,25(OH)(2)-vitamin D-3 alone or combined with 17beta-E-2, to 169% and 198% and to 144% and 144% of control value, respectively. 1alpha,25(OH)(2)-vitamin D-3, with or without 17beta-E-2, decreased interleukin-6 levels to 27% and 38% of control group, respectively. Conclusion(s): 17beta-E-2 and 1alpha,25(OH)(2)-vitamin D-3 have effects on osteoblasts. The prevention of osteoporosis by estrogen may be related not only to direct effects on osteoblastic activity and proliferation but also to indirect effects on osteoblasts by the decrease of interleukin-6 secretion. (Fertil Steril(R) 2002;77:1038-43, (C) 2002 by American Society for Reproductive Medicine).