Insulin-like growth factor binding protein (IGFBP)-3 effects proliferation and differentiation of numerous cell types by binding to insulin-like growth factors (IGF) and attenuating their activity or by directly affecting cells in an IGFindependent manner. Consequently, IGFBPs produced by specific c
Effects of progesterone on serum levels of IGF-1 and on femur IGF-1 mRNA in ovariectomized rats
β Scribed by E.I. Barengolts; T. Kouznetsova; A. Segalene; P. Lathon; C. Odvina; S.C. Kukreja; T.G. Unterman
- Publisher
- American Society for Bone and Mineral Research
- Year
- 2009
- Tongue
- English
- Weight
- 867 KB
- Volume
- 11
- Category
- Article
- ISSN
- 0884-0431
No coin nor oath required. For personal study only.
β¦ Synopsis
Local and systemic insulin-like growth factors (IGFs) may be involved in the regulation of bone formation by sex hormones. The present studies describe the in vivo effects of estradiol, progesterone, or both on IGF-1 mRNA abundance in bone, serum IGF-1 levels, and bone formation. Rats were sham-operated (SHAM) or ovariectomized (OVX) at 12 weeks of age and used a week later in three experiments. First, OVX rats were treated with vehicle, estradiol, and/or medroqprogesterone (MPA) for 3 weeks, and bone formation was assessed in the tibia1 metaphysis. Second, OVX rats were treated in the same manner and serum IGF-1 levels measured. Third, OVX rats were treated with an injection of vehicle, estradiol, and/or progesterone, and 24 h later, levels of IGF-1 mRNA in the femur were analyzed. The mineralized surface, mineral apposition rate, and bone formation rate (BFR) were higher in OVX than in SHAM rats. The BFR was decreased in estrogen-treated but increased in MPA-treated rats compared with vehicle-treated OVX rats. Circulating levels of IGF-1 were higher in OVX than in SHAM rats but were not affected by sex hormones in a 3-week experiment, whereas these levels were not different among groups in a 24-h experiment. Northern analysis detected 7.5 and 0.8 kb IGF-1 mRNA transcripts. The abundance of IGF-1 mRNA was higher in OVX than in SHAM rats. IGF-1 transcripts 7.5 and 0.8 kb were decreased by 72 and ~W O , respectively, in estrogen-treated and increased by 44 and 43%, respectively, in progesterone-treated rats compared with vehicle-treated O W rats. We conclude that in the short term, estrogen lowers and progesterone raises bone IGF-1 mRNA and these changes are followed by coordinated changes in bone formation rate. (
π SIMILAR VOLUMES
## Abstract The present study investigated the role of swimming training on cerebral metabolism and hippocampus concentrations of insulin and IGFβ1 in diabetic rats. Wistar rats were divided in sedentary control (SC), trained control (TC), sedentary diabetic (SD), and trained diabetic (TD). Diabete
Use of recombinant insulin-like growth factor 1 (IGF-1) as a treatment for primary IGF-1 deficiency in children has become increasingly common. When untreated, primary IGF-1 deficiency may lead to a range of metabolic disorders, including lipid abnormalities, insulin resistance, and decreased bone d
## Abstract Age is an important predictor of neuromuscular recovery after peripheral nerve injury. Insulinβlike growth factor 1 (IGFβ1) is a potent neurotrophic factor that is known to decline with increasing age. The purpose of this study was to determine if locally delivered IGFβ1 would improve n