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Updated: Aug 20, 2026
Estrogen-Like Effect of Bazi Bushen Capsule in Ovariectomized Rats
Published on: April 7, 2023
Effects of dihydrotestrone on osteoblast gene expression in osteopenic ovariectomized rats
1Hanson Institute, Adelaide, South Australia, Australia. r.davey@unimelb.edu.au
Abstract:
Androgens stimulate bone formation, however, the precise mechanism of androgen action on osteoblasts remains to be elucidated. In this study, we defined the expression profile of osteoblast genes in ovariectomized rats with established osteopenia and their response to treatment with dihydrotestosterone (DHT). Twenty-four, 8-month-old female Sprague-Dawley rats were ovariectomized (ovx) and were administered vehicle, 40 mg, 80 mg, or 160 mg/kg body weight DHT at 15-weeks post-ovariectomy for 14 weeks. Alkaline phosphatase (ALP) messenger ribonucleic acid (mRNA) levels were increased at 29-weeks post-ovariectomy compared with preoperative rats (P < 0.05). In contrast, osteopontin and osteocalcin mRNA levels were unchanged. Treatment of osteopenic ovx rats with DHT for 14 weeks suppressed the ovariectomy-induced increase in ALP (P < 0.05) mRNA levels, independent of dose. These data suggest that androgens may act to inhibit the stimulation of the early stages of osteoblast development that occurs in the absence of estrogen and in states of low bone turnover.
Insights
Androgens, like dihydrotestosterone (DHT), may inhibit early osteoblast development in estrogen-deficient states. This study observed DHT suppressing an ovariectomy-induced increase in alkaline phosphatase (ALP) mRNA in rats.
Area of Science:
- Bone Biology
- Endocrinology
- Osteoblastogenesis
Background:
- Androgens are known to stimulate bone formation, but their precise mechanisms on osteoblasts are not fully understood.
- Estrogen deficiency, as seen in ovariectomized (ovx) rodents, leads to changes in bone turnover and osteopenia.
- Understanding androgen effects is crucial for developing therapies for bone loss.
Purpose of the Study:
- To investigate the gene expression profile of osteoblasts in ovariectomized rats with osteopenia.
- To determine the effect of dihydrotestosterone (DHT) treatment on osteoblast gene expression in this model.
- To elucidate the role of androgens in the context of estrogen deficiency and low bone turnover.
Main Methods:
- Ovariectomy was performed on 24 female Sprague-Dawley rats.
- Rats received vehicle or varying doses of DHT (40, 80, 160 mg/kg) for 14 weeks, starting 15 weeks post-ovariectomy.
- Messenger RNA (mRNA) levels of alkaline phosphatase (ALP), osteopontin, and osteocalcin were analyzed.
Main Results:
- Ovariectomy increased alkaline phosphatase (ALP) mRNA levels compared to preoperative levels.
- Osteopontin and osteocalcin mRNA levels remained unchanged post-ovariectomy.
- DHT treatment suppressed the ovariectomy-induced increase in ALP mRNA levels in a dose-independent manner.
Conclusions:
- Androgens, such as DHT, may inhibit the early stages of osteoblast development.
- This inhibitory effect appears to occur in the absence of estrogen and during periods of low bone turnover.
- Findings suggest a complex regulatory role for androgens in bone metabolism beyond direct stimulation.
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