Abstract
High-affinity nuclear binding sites for 17 beta-estradiol (17 beta E2) were recently found in bone cells; however, the mechanism by which estrogen exerts its effect on bone in vivo is still unknown. To study if estrogen acts on bone directly, we used an experimental model in which test substances are infused locally into rat femur trabecular bone. Sprague-Dawley rats weighing 150-160 g were ovariectomized (OVX) and 14 days later a polyethylene tube (1 mm in diameter) connected to an Alzet osmotic minipump was implanted into the distal femur 9 mm from the joint. 17 beta E2 (24 microliters/day at 0.01-1 nM), 17 alpha-estradiol (17 alpha E2) (24 microliters/day at 1 nM), or phosphate-buffered saline (NaCl, 8 g/liter; KCl, 0.2 g/liter; KH2PO4, 0.2 g/liter; Na2HPO4.7H2O, 2.16 g/liter) was infused for 8 days. The contralateral limb remained intact. Animals were sacrificed and bones were examined by histomorphometry. Ovariectomy caused a 50% loss in trabecular bone volume (TBV) in the secondary spongiosa (from 20.3% +/- 1.7% to 9.6% +/- 1.1%; mean +/- SEM), a 2-fold increase in osteoclast number (to 4.0 +/- 0.4 per mm), a 3-fold increase in relative resorption surfaces (to 24.8% +/- 2.9%), a 9-fold increase in osteoblast number (to 11.3 +/- 2.1 per mm), and an 8-fold increase in relative osteoid surface (to 9.6% +/- 1.7%). The local infusion of 17 beta E2 for 8 days into OVX rats (i) restored the TBV dose dependently to 75% and 85% of control (non-OVX) levels, at 0.1 nM and 1 nM 17 beta E2, respectively; (ii) decreased osteoclast number and the relative resorption surface to control (non-OVX) levels; and (iii) further increased osteoblast number and the relative osteoid surface dose dependently (by 5-fold at 1 nM 17 beta E2). Phosphate-buffered saline infusion was without effect. Infusion of 17 alpha E2 had no effect on TBV, osteoclast number, or resorption surface but increased slightly the osteoblast number and the osteoid surface. Its potency was 1/100 that of 17 beta E2. The local infusion of 17 beta E2 or 17 alpha E2 had no effect on body or uterine weight. We conclude from these findings that estrogen delivered directly to the bone of OVX rats in vivo at 2.4 and 24 fmol/day acted locally to inhibit bone resorption and stimulate bone formation.
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- Aitken J. M., Armstrong E., Anderson J. B. Osteoporosis after oophorectomy in the mature female rat and the effect of oestrogen and-or progestogen replacement therapy in its prevention. J Endocrinol. 1972 Oct;55(1):79–87. doi: 10.1677/joe.0.0550079. [DOI] [PubMed] [Google Scholar]
- Atkins D., Zanelli J. M., Peacock M., Nordin B. E. The effect of oestrogens on the response of bone to parathyroid hormone in vitro. J Endocrinol. 1972 Jul;54(1):107–117. doi: 10.1677/joe.0.0540107. [DOI] [PubMed] [Google Scholar]
- Butcher R. L., Collins W. E., Fugo N. W. Plasma concentration of LH, FSH, prolactin, progesterone and estradiol-17beta throughout the 4-day estrous cycle of the rat. Endocrinology. 1974 Jun;94(6):1704–1708. doi: 10.1210/endo-94-6-1704. [DOI] [PubMed] [Google Scholar]
- Canalis E., McCarthy T., Centrella M. Growth factors and the regulation of bone remodeling. J Clin Invest. 1988 Feb;81(2):277–281. doi: 10.1172/JCI113318. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Canalis E., McCarthy T., Centrella M. Isolation and characterization of insulin-like growth factor I (somatomedin-C) from cultures of fetal rat calvariae. Endocrinology. 1988 Jan;122(1):22–27. doi: 10.1210/endo-122-1-22. [DOI] [PubMed] [Google Scholar]
- Canalis E., Raisz L. G. Effect of sex steroids on bone collagen synthesis in vitro. Calcif Tissue Res. 1978 May 26;25(2):105–110. doi: 10.1007/BF02010758. [DOI] [PubMed] [Google Scholar]
- Caputo C. B., Meadows D., Raisz L. G. Failure of estrogens and androgens to inhibit bone resorption in tissue culture. Endocrinology. 1976 Apr;98(4):1065–1068. doi: 10.1210/endo-98-4-1065. [DOI] [PubMed] [Google Scholar]
- Centrella M., Canalis E. Isolation of EGF-dependent transforming growth factor (TGF beta-like) activity from culture medium conditioned by fetal rat calvariae. J Bone Miner Res. 1987 Feb;2(1):29–36. doi: 10.1002/jbmr.5650020106. [DOI] [PubMed] [Google Scholar]
- Centrella M., Canalis E. Transforming and nontransforming growth factors are present in medium conditioned by fetal rat calvariae. Proc Natl Acad Sci U S A. 1985 Nov;82(21):7335–7339. doi: 10.1073/pnas.82.21.7335. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chen T. L., Feldman D. Distinction between alpha-fetoprotein and intracellular estrogen receptors: evidence against the presence of estradiol receptors in rat bone. Endocrinology. 1978 Jan;102(1):236–244. doi: 10.1210/endo-102-1-236. [DOI] [PubMed] [Google Scholar]
- Cruess R. L., Hong K. C. Effect of estrogen on the collagenolytic activity of rat bone. Calcif Tissue Res. 1976 Jun 14;20(3):317–320. doi: 10.1007/BF02546419. [DOI] [PubMed] [Google Scholar]
- Edwards D. P., McGuire W. L. 17 alpha-Estradiol is a biologically active estrogen in human breast cancer cells in tissue culture. Endocrinology. 1980 Oct;107(4):884–891. doi: 10.1210/endo-107-4-884. [DOI] [PubMed] [Google Scholar]
- Eriksen E. F., Colvard D. S., Berg N. J., Graham M. L., Mann K. G., Spelsberg T. C., Riggs B. L. Evidence of estrogen receptors in normal human osteoblast-like cells. Science. 1988 Jul 1;241(4861):84–86. doi: 10.1126/science.3388021. [DOI] [PubMed] [Google Scholar]
- Ernst M., Heath J. K., Rodan G. A. Estradiol effects on proliferation, messenger ribonucleic acid for collagen and insulin-like growth factor-I, and parathyroid hormone-stimulated adenylate cyclase activity in osteoblastic cells from calvariae and long bones. Endocrinology. 1989 Aug;125(2):825–833. doi: 10.1210/endo-125-2-825. [DOI] [PubMed] [Google Scholar]
- Ernst M., Schmid C., Froesch E. R. Enhanced osteoblast proliferation and collagen gene expression by estradiol. Proc Natl Acad Sci U S A. 1988 Apr;85(7):2307–2310. doi: 10.1073/pnas.85.7.2307. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Feyen J. H., Raisz L. G. Prostaglandin production by calvariae from sham operated and oophorectomized rats: effect of 17 beta-estradiol in vivo. Endocrinology. 1987 Aug;121(2):819–821. doi: 10.1210/endo-121-2-819. [DOI] [PubMed] [Google Scholar]
- Fukayama S., Tashjian A. H., Jr Direct modulation by estradiol of the response of human bone cells (SaOS-2) to human parathyroid hormone (PTH) and PTH-related protein. Endocrinology. 1989 Jan;124(1):397–401. doi: 10.1210/endo-124-1-397. [DOI] [PubMed] [Google Scholar]
- GORDAN G. S., EISENBERG E. THE EFFECT OF OESTROGENS, ANDROGENS AND CORTICOIDS ON SKELETAL KINETICS IN MAN. Proc R Soc Med. 1963 Nov;56:1027–1029. [PMC free article] [PubMed] [Google Scholar]
- Gallagher J. C., Riggs B. L., DeLuca H. F. Effect of estrogen on calcium absorption and serum vitamin D metabolites in postmenopausal osteoporosis. J Clin Endocrinol Metab. 1980 Dec;51(6):1359–1364. doi: 10.1210/jcem-51-6-1359. [DOI] [PubMed] [Google Scholar]
- Gallagher J. C., Wilkinson R. The effect of ethinyloestradiol on calcium and phosphorus metabolism of post-menopausal women with primary hyperparathyroidism. Clin Sci Mol Med. 1973 Dec;45(6):785–802. doi: 10.1042/cs0450785. [DOI] [PubMed] [Google Scholar]
- Gray T. K., Flynn T. C., Gray K. M., Nabell L. M. 17 beta-estradiol acts directly on the clonal osteoblastic cell line UMR106. Proc Natl Acad Sci U S A. 1987 Sep;84(17):6267–6271. doi: 10.1073/pnas.84.17.6267. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gray T. K., Mohan S., Linkhart T. A., Baylink D. J. Estradiol stimulates in vitro the secretion of insulin-like growth factors by the clonal osteoblastic cell line, UMR106. Biochem Biophys Res Commun. 1989 Jan 31;158(2):407–412. doi: 10.1016/s0006-291x(89)80062-2. [DOI] [PubMed] [Google Scholar]
- Horsman A., Gallagher J. C., Simpson M., Nordin B. E. Prospective trial of oestrogen and calcium in postmenopausal women. Br Med J. 1977 Sep 24;2(6090):789–792. doi: 10.1136/bmj.2.6090.789. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Imanaka S., Morimoto S., Onishi T., Takamoto S., Fukuo K., Koh E., Itoh K., Hironaka T., Shiraishi T., Morita R. Effect of estrogens on renal responsiveness to parathyroid hormone in elderly female subjects. Endocrinol Jpn. 1988 Aug;35(4):593–599. doi: 10.1507/endocrj1954.35.593. [DOI] [PubMed] [Google Scholar]
- Ismail F., Epstein S., Fallon M. D., Thomas S. B., Reinhardt T. A. Serum bone gla protein and the vitamin D endocrine system in the oophorectomized rat. Endocrinology. 1988 Feb;122(2):624–630. doi: 10.1210/endo-122-2-624. [DOI] [PubMed] [Google Scholar]
- Komm B. S., Terpening C. M., Benz D. J., Graeme K. A., Gallegos A., Korc M., Greene G. L., O'Malley B. W., Haussler M. R. Estrogen binding, receptor mRNA, and biologic response in osteoblast-like osteosarcoma cells. Science. 1988 Jul 1;241(4861):81–84. doi: 10.1126/science.3164526. [DOI] [PubMed] [Google Scholar]
- Kusuhara S., Schraer H. Cytology and autoradiography of estrogen-induced differentiation of avian endosteal cells. Calcif Tissue Int. 1982 Jul;34(4):352–358. doi: 10.1007/BF02411267. [DOI] [PubMed] [Google Scholar]
- Langeland N. The in vitro effect of oestradiol on collagen metabolism in metaphyseal rat bone. Acta Orthop Scand. 1977;48(3):266–272. doi: 10.3109/17453677708988766. [DOI] [PubMed] [Google Scholar]
- Lindsay R., Hart D. M., Aitken J. M., MacDonald E. B., Anderson J. B., Clarke A. C. Long-term prevention of postmenopausal osteoporosis by oestrogen. Evidence for an increased bone mass after delayed onset of oestrogen treatment. Lancet. 1976 May 15;1(7968):1038–1041. doi: 10.1016/s0140-6736(76)92217-0. [DOI] [PubMed] [Google Scholar]
- Liskova M. Influence of estrogens on bone resorption in organ culture. Calcif Tissue Res. 1976 Dec 22;22(2):207–218. doi: 10.1007/BF02010359. [DOI] [PubMed] [Google Scholar]
- Miller S. C., Bowman B. M. Medullary bone osteogenesis following estrogen administration to mature male Japanese quail. Dev Biol. 1981 Oct 15;87(1):52–63. doi: 10.1016/0012-1606(81)90060-9. [DOI] [PubMed] [Google Scholar]
- Nutik G., Cruess R. L. Estrogen receptors in bone. An evaluation of the uptake of estrogen into bone cells. Proc Soc Exp Biol Med. 1974 May;146(1):265–268. doi: 10.3181/00379727-146-38084. [DOI] [PubMed] [Google Scholar]
- Pansini F., Bergamini C. M., Bellinazzi A., Andreoli M., Perri G., Bagni B., Mollica G. Ovarian steroids modulate the action of calcitonin in women. J Endocrinol. 1988 Jan;116(1):155–159. doi: 10.1677/joe.0.1160155. [DOI] [PubMed] [Google Scholar]
- Raisz L. G. Local and systemic factors in the pathogenesis of osteoporosis. N Engl J Med. 1988 Mar 31;318(13):818–828. doi: 10.1056/NEJM198803313181305. [DOI] [PubMed] [Google Scholar]
- Riggs B. L., Jowsey J., Goldsmith R. S., Kelly P. J., Hoffman D. L., Arnaud C. D. Short- and long-term effects of estrogen and synthetic anabolic hormone in postmenopausal osteoporosis. J Clin Invest. 1972 Jul;51(7):1659–1663. doi: 10.1172/JCI106967. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Saville P. D. Changes in skeletal mass and fragility with castration in the rat; a model of osteoporosis. J Am Geriatr Soc. 1969 Feb;17(2):155–166. doi: 10.1111/j.1532-5415.1969.tb03169.x. [DOI] [PubMed] [Google Scholar]
- Seaman W. E., Gindhart T. D., Greenspan J. S., Blackman M. A., Talal N. Natural killer cells, bone, and the bone marrow: studies in estrogen-treated mice and in congenitally osteopetrotic (mi/mi) mice. J Immunol. 1979 Jun;122(6):2541–2547. [PubMed] [Google Scholar]
- Shull J. D., Gorski J. Estrogen regulation of prolactin gene transcription in vivo: paradoxical effects of 17 beta-estradiol dose. Endocrinology. 1989 Jan;124(1):279–285. doi: 10.1210/endo-124-1-279. [DOI] [PubMed] [Google Scholar]
- Sivam G., Cohen M. S., Dodd R. C., Gray T. K. 17 Beta-estradiol inhibits the oxidative metabolism of U937 cells indirectly via lymphocytes. Endocrinology. 1987 Sep;121(3):853–857. doi: 10.1210/endo-121-3-853. [DOI] [PubMed] [Google Scholar]
- Soto A. M., Sonnenschein C. Cell proliferation of estrogen-sensitive cells: the case for negative control. Endocr Rev. 1987 Feb;8(1):44–52. doi: 10.1210/edrv-8-1-44. [DOI] [PubMed] [Google Scholar]
- Stewart P. J., Stern P. H. Vertebral bone resorption in vitro: effects of parathyroid hormone, calcitonin, 1,25 dihydroxyvitamin D3, epidermal growth factor, prostaglandin E2, and estrogen. Calcif Tissue Int. 1987 Jan;40(1):21–26. doi: 10.1007/BF02555724. [DOI] [PubMed] [Google Scholar]
- Stock J. L., Coderre J. A., Mallette L. E. Effects of a short course of estrogen on mineral metabolism in postmenopausal women. J Clin Endocrinol Metab. 1985 Oct;61(4):595–600. doi: 10.1210/jcem-61-4-595. [DOI] [PubMed] [Google Scholar]
- Turner R. T., Vandersteenhoven J. J., Bell N. H. The effects of ovariectomy and 17 beta-estradiol on cortical bone histomorphometry in growing rats. J Bone Miner Res. 1987 Apr;2(2):115–122. doi: 10.1002/jbmr.5650020206. [DOI] [PubMed] [Google Scholar]
- Turner R. T., Wakley G. K., Hannon K. S., Bell N. H. Tamoxifen inhibits osteoclast-mediated resorption of trabecular bone in ovarian hormone-deficient rats. Endocrinology. 1988 Mar;122(3):1146–1150. doi: 10.1210/endo-122-3-1146. [DOI] [PubMed] [Google Scholar]
- URIST M. R., BUDY A. M., McLEAN F. C. Endosteal-bone formation in estrogen-treated mice. J Bone Joint Surg Am. 1950 Jan;32A(1):143-62, illust. [PubMed] [Google Scholar]
- Williams G. A., Kukreja S. C., Bowser E. N., Hargis G. K., Greenberg C. P., Henderson W. J. Prolonged effect of estradiol on calcitonin secretion. Bone Miner. 1986 Oct;1(5):415–420. [PubMed] [Google Scholar]
- Wronski T. J., Cintrón M., Dann L. M. Temporal relationship between bone loss and increased bone turnover in ovariectomized rats. Calcif Tissue Int. 1988 Sep;43(3):179–183. doi: 10.1007/BF02571317. [DOI] [PubMed] [Google Scholar]
- Wronski T. J., Cintrón M., Doherty A. L., Dann L. M. Estrogen treatment prevents osteopenia and depresses bone turnover in ovariectomized rats. Endocrinology. 1988 Aug;123(2):681–686. doi: 10.1210/endo-123-2-681. [DOI] [PubMed] [Google Scholar]
- Wronski T. J., Walsh C. C., Ignaszewski L. A. Histologic evidence for osteopenia and increased bone turnover in ovariectomized rats. Bone. 1986;7(2):119–123. doi: 10.1016/8756-3282(86)90683-6. [DOI] [PubMed] [Google Scholar]