Send to

Choose Destination
Biochem Biophys Res Commun. 1993 Aug 16;194(3):1228-33.

Ovariectomy decreases the mRNA levels of transforming growth factor-beta 1 and increases the mRNA levels of osteocalcin in rat bone in vivo.

Author information

Department of Orthopaedic Surgery, Kyoto University Faculty of Medicine, Japan.


Estrogen depletion causes postmenopausal osteoporosis. Here we report that steady state mRNA levels of transforming growth factor-beta 1 (TGF-beta 1) and osteocalcin in bone persistently decreased and increased, respectively, in vivo in estrogen-depleted rats after ovariectomy (OVX). 21 female Wistar rats (7-month-old) were randomized and underwent OVX or sham-operation, total RNA was extracted from tibiae and assessed by Northern blot analysis. OVX induced 70-80% decrease in TGF-beta 1 mRNA levels and 2- to 3-fold increase in mRNA levels of osteocalcin compared with controls three weeks after surgery. These changes persisted up to twelve weeks post-operation. OVX caused 15% reduction in femoral bone mineral density and 2-fold elevation in serum osteocalcin levels as early as two weeks post-operation. Moreover, estrogen depletion resulted in marked decrease and increase, respectively, in steady state mRNA levels of TGF-beta 1 and osteocalcin in vitro in osteoblastic rat osteosarcoma cells, ROS 17/2.8. Our results provide the first in vivo evidence that expression of TGF-beta and osteocalcin in bone is reciprocally regulated at the transcriptional level in estrogen deficient OVX rats and suggests that TGF-beta 1 may play a role in estrogen-dependent maintenance of normal bone density.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center