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Li X, Yu L, Asuncion F, Grisanti M, Alexander S, Hensley K, Han CY, Niu QT, Dwyer D, Villasenor K, Stolina M, Dean C, Ominsky MS, Ke HZ, Tomlinson JE, Richards WG. Etelcalcetide (AMG 416), a peptide agonist of the calcium-sensing receptor, preserved cortical bone structure and bone strength in subtotal nephrectomized rats with established secondary hyperparathyroidism. Bone 2017; 105:163-172. [PMID: 28867373 DOI: 10.1016/j.bone.2017.08.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 08/24/2017] [Accepted: 08/28/2017] [Indexed: 10/18/2022]
Abstract
Sustained elevation of parathyroid hormone (PTH) is catabolic to cortical bone, as evidenced by deterioration in bone structure (cortical porosity), and is a major factor for increased fracture risk in chronic kidney disease (CKD). Etelcalcetide (AMG 416), a novel peptide agonist of the calcium-sensing receptor, reduces PTH levels in subtotal nephrectomized (Nx) rats and in hemodialysis patients with secondary hyperparathyroidism (SHPT) in clinical studies; however, effects of etelcalcetide on bone have not been determined. In a rat model of established SHPT with renal osteodystrophy, etelcalcetide or vehicle was administered by subcutaneous (s.c.) injection to subtotal Nx rats with elevated PTH (>750pg/mL) once per day for 6weeks. Sham-operated rats receiving vehicle (s.c.) served as non-SHPT controls. Prior to treatment, significant increases in serum creatinine (2-fold), blood urea nitrogen (BUN, 3-fold), PTH (5-fold), fibroblast growth factor-23 (FGF23; 13-fold) and osteocalcin (12-fold) were observed in SHPT rats compared to non-SHPT controls. Elevations in serum creatinine and BUN were unaffected by treatment with vehicle or etelcalcetide. In contrast, etelcalcetide significantly decreased PTH, FGF23 and osteocalcin, whereas vehicle treatment did not. Cortical bone porosity increased and bone strength decreased in vehicle-treated SHPT rats compared to non-SHPT controls. Cortical bone structure improved and energy to failure was significantly greater in SHPT rats treated with etelcalcetide compared to vehicle. Mineralization lag time and marrow fibrosis were significantly reduced by etelcalcetide. In conclusion, etelcalcetide reduced bone turnover, attenuated mineralization defect and marrow fibrosis, and preserved cortical bone structure and bone strength by lowering PTH in subtotal Nx rats with established SHPT.
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Affiliation(s)
- Xiaodong Li
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA.
| | - Longchuan Yu
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Frank Asuncion
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Mario Grisanti
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Shawn Alexander
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Kelly Hensley
- Department of Comparative Biology and Safety Sciences, Amgen Inc., Thousand Oaks, CA, USA
| | - Chun-Ya Han
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Qing-Tian Niu
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Denise Dwyer
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Kelly Villasenor
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Marina Stolina
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Charles Dean
- Department of Comparative Biology and Safety Sciences, Amgen Inc., Thousand Oaks, CA, USA
| | - Michael S Ominsky
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Hua Zhu Ke
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - James E Tomlinson
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - William G Richards
- Department of Cardiometabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
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2
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Yamaguchi I, Myojo K, Sanada H, Takami A, Suzuki Y, Imaizumi M, Takada C, Kimoto N, Saeki K, Yamate J, Takaba K. Five-sixth Nephrectomy in Female Common Marmosets(Callithrix jacchus) as a Chronic Renal Failure Model: -A Longitudinal Course of Serum Biochemical, Hematological and Histopathological Changes-. J Toxicol Pathol 2014; 27:183-95. [PMID: 25378803 PMCID: PMC4217228 DOI: 10.1293/tox.2013-0055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 06/04/2014] [Indexed: 12/29/2022] Open
Abstract
To assess the relevance and availability of subtotal nephrectomized common marmoset monkeys as a chronic renal failure (CRF) model, we observed for 26 weeks the pathophysiological condition of female marmosets subjected to five-sixth surgical nephrectomy (5/6Nx) by a two-step surgical method. The 5/6Nx marmosets showed a significant increase in serum levels of urea nitrogen, creatinine and cystatin-C immediately after 5/6Nx surgery. These renal disorder parameters subsequently tended to decrease with the passage of time but remained higher than the control levels by the end of the study. Hyperplastic parathyroid glands, a high turnover state of osteodystrophy in the femoral bone with higher serum ALP activity and anemia with hypocellularity of bone marrow were evident. The 5/6Nx marmosets showed a stable CRF condition for a long time and some characteristic disorders similar to those observed in CRF patients. These diagnostic aspects might be a species-specific anatomical and physiological signature, reflecting the nutritional condition. The CRF model using 5/6Nx marmosets might become a useful method of evaluating the unique mechanism of CRF development.
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Affiliation(s)
- Itaru Yamaguchi
- Fuji Research Park, Kyowa Hakko Kirin Co., Ltd., 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 411–8731, Japan
| | - Kensuke Myojo
- Fuji Research Park, Kyowa Hakko Kirin Co., Ltd., 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 411–8731, Japan
| | - Hiroko Sanada
- Fuji Research Park, Kyowa Hakko Kirin Co., Ltd., 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 411–8731, Japan
| | - Atsuko Takami
- Fuji Research Park, Kyowa Hakko Kirin Co., Ltd., 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 411–8731, Japan
| | - Yui Suzuki
- Fuji Research Park, Kyowa Hakko Kirin Co., Ltd., 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 411–8731, Japan
- Veterinary Pathology, Osaka Prefecture University, 1–58 Rinkuu Ourai Kita, Izumisano, Osaka 598–8531, Japan
| | - Minami Imaizumi
- Fuji Research Park, Kyowa Hakko Kirin Co., Ltd., 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 411–8731, Japan
| | - Chie Takada
- Fuji Research Park, Kyowa Hakko Kirin Co., Ltd., 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 411–8731, Japan
| | - Naoya Kimoto
- Fuji Research Park, Kyowa Hakko Kirin Co., Ltd., 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 411–8731, Japan
| | - Koji Saeki
- Fuji Research Park, Kyowa Hakko Kirin Co., Ltd., 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 411–8731, Japan
| | - Jyoji Yamate
- Veterinary Pathology, Osaka Prefecture University, 1–58 Rinkuu Ourai Kita, Izumisano, Osaka 598–8531, Japan
| | - Katsumi Takaba
- Fuji Research Park, Kyowa Hakko Kirin Co., Ltd., 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka 411–8731, Japan
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Mechanistic investigations on the etiology of Risperdal® Consta®-induced bone changes in female Wistar Hannover rats. Toxicology 2012; 299:90-8. [DOI: 10.1016/j.tox.2012.05.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 05/04/2012] [Accepted: 05/05/2012] [Indexed: 11/21/2022]
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4
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Shalhoub V, Shatzen EM, Ward SC, Davis J, Stevens J, Bi V, Renshaw L, Hawkins N, Wang W, Chen C, Tsai MM, Cattley RC, Wronski TJ, Xia X, Li X, Henley C, Eschenberg M, Richards WG. FGF23 neutralization improves chronic kidney disease-associated hyperparathyroidism yet increases mortality. J Clin Invest 2012; 122:2543-53. [PMID: 22728934 DOI: 10.1172/jci61405] [Citation(s) in RCA: 311] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 05/10/2012] [Indexed: 12/27/2022] Open
Abstract
Chronic kidney disease-mineral and bone disorder (CKD-MBD) is associated with secondary hyperparathyroidism (HPT) and serum elevations in the phosphaturic hormone FGF23, which may be maladaptive and lead to increased morbidity and mortality. To determine the role of FGF23 in the pathogenesis of CKD-MBD and development of secondary HPT, we developed a monoclonal FGF23 antibody to evaluate the impact of chronic FGF23 neutralization on CKD-MBD, secondary HPT, and associated comorbidities in a rat model of CKD-MBD. CKD-MBD rats fed a high-phosphate diet were treated with low or high doses of FGF23-Ab or an isotype control antibody. Neutralization of FGF23 led to sustained reductions in secondary HPT, including decreased parathyroid hormone, increased vitamin D, increased serum calcium, and normalization of bone markers such as cancellous bone volume, trabecular number, osteoblast surface, osteoid surface, and bone-formation rate. In addition, we observed dose-dependent increases in serum phosphate and aortic calcification associated with increased risk of mortality in CKD-MBD rats treated with FGF23-Ab. Thus, mineral disturbances caused by neutralization of FGF23 limited the efficacy of FGF23-Ab and likely contributed to the increased mortality observed in this CKD-MBD rat model.
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Affiliation(s)
- Victoria Shalhoub
- Department of Metabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
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Uchida H, Kurata Y, Hiratsuka H, Umemura T. The Effects of a Vitamin D–deficient Diet on Chronic Cadmium Exposure in Rats. Toxicol Pathol 2010; 38:730-7. [DOI: 10.1177/0192623310374328] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Itai-itai disease (IID) of humans is one of the most severe forms of chronic cadmium (Cd) intoxication. Itai-itai disease occurs mainly in post-menopausal women and is characterized by osteoporosis with osteomalacia, renal tubular disorder, and renal anemia. Some researchers insist the major cause of IID is not Cd, but rather malnutrition, especially hypovitaminosis D. We administrated a low concentration of Cd chloride intravenously to ovariectomized female rats that were fed a vitamin D–deficient diet or a normal diet for fifty weeks. The vitamin D–deficient diet decreased serum concentration of vitamin D, but it did not affect the metabolism of the kidney or bone. Cadmium treatment alone induced a decrease in serum concentration of vitamin D, as well as renal dysfunction, renal anemia, and abnormal bone metabolism. Osteoporosis with osteomalacia, tubular nephropathy, fibrous osteodystrophy, and bone marrow hyperplasia occurred following Cd treatment. In rats treated with Cd and administered a vitamin D–deficient diet, the toxic effects of Cd on kidney, bone, and hematopoiesis were enhanced in comparison to rats treated with Cd and a normal diet. The present experiment demonstrated that hypovitaminosis D did not evoke morphologic features of IID in humans but did enhance Cd-induced toxicity in the rat model of this disease.
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Affiliation(s)
- Hideomi Uchida
- Kumamoto Laboratory, Toxicological Science Division, Medi-Chem Business
Segment, Mitsubishi Chemical Medience Corporation, Kumamoto 869-0425, Japan
- Laboratory of Comparative Pathology, Graduate School of Veterinary
Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Yoshimasa Kurata
- Kashima Laboratory, Toxicological Science Division, Medi-Chem Business
Segment, Mitsubishi Chemical Medience Corporation, Ibaraki 314-0255, Japan
| | - Hideaki Hiratsuka
- Kashima Laboratory, Toxicological Science Division, Medi-Chem Business
Segment, Mitsubishi Chemical Medience Corporation, Ibaraki 314-0255, Japan
| | - Takashi Umemura
- Laboratory of Comparative Pathology, Graduate School of Veterinary
Medicine, Hokkaido University, Sapporo 060-0818, Japan
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Cao H, Nazarian A, Ackerman JL, Snyder BD, Rosenberg AE, Nazarian RM, Hrovat MI, Dai G, Mintzopoulos D, Wu Y. Quantitative (31)P NMR spectroscopy and (1)H MRI measurements of bone mineral and matrix density differentiate metabolic bone diseases in rat models. Bone 2010; 46:1582-90. [PMID: 20188225 PMCID: PMC2875334 DOI: 10.1016/j.bone.2010.02.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Revised: 12/18/2009] [Accepted: 02/18/2010] [Indexed: 11/29/2022]
Abstract
In this study, bone mineral density (BMD) of normal (CON), ovariectomized (OVX), and partially nephrectomized (NFR) rats was measured by (31)P NMR spectroscopy; bone matrix density was measured by (1)H water- and fat-suppressed projection imaging (WASPI); and the extent of bone mineralization (EBM) was obtained by the ratio of BMD/bone matrix density. The capability of these MR methods to distinguish the bone composition of the CON, OVX, and NFR groups was evaluated against chemical analysis (gravimetry). For cortical bone specimens, BMD of the CON and OVX groups was not significantly different; BMD of the NFR group was 22.1% (by (31)P NMR) and 17.5% (by gravimetry) lower than CON. For trabecular bone specimens, BMD of the OVX group was 40.5% (by (31)P NMR) and 24.6% (by gravimetry) lower than CON; BMD of the NFR group was 26.8% (by (31)P NMR) and 21.5% (by gravimetry) lower than CON. No significant change of cortical bone matrix density between CON and OVX was observed by WASPI or gravimetry; NFR cortical bone matrix density was 10.3% (by WASPI) and 13.9% (by gravimetry) lower than CON. OVX trabecular bone matrix density was 38.0% (by WASPI) and 30.8% (by gravimetry) lower than CON, while no significant change in NFR trabecular bone matrix density was observed by either method. The EBMs of OVX cortical and trabecular specimens were slightly higher than CON but not significantly different from CON. Importantly, EBMs of NFR cortical and trabecular specimens were 12.4% and 26.3% lower than CON by (31)P NMR/WASPI, respectively, and 4.0% and 11.9% lower by gravimetry. Histopathology showed evidence of osteoporosis in the OVX group and severe secondary hyperparathyroidism (renal osteodystrophy) in the NFR group. These results demonstrate that the combined (31)P NMR/WASPI method is capable of discerning the difference in EBM between animals with osteoporosis and those with impaired bone mineralization.
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Affiliation(s)
- Haihui Cao
- Department of Orthopaedic Surgery, Children’s Hospital, Boston, MA 02115
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129
- Harvard Medical School, Boston, MA 02115
| | - Ara Nazarian
- Center for Advanced Orthopaedic Studies, Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215
- Harvard Medical School, Boston, MA 02115
| | - Jerome L. Ackerman
- Department of Orthopaedic Surgery, Children’s Hospital, Boston, MA 02115
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA 02139
- Harvard Medical School, Boston, MA 02115
| | - Brian D. Snyder
- Department of Orthopaedic Surgery, Children’s Hospital, Boston, MA 02115
- Center for Advanced Orthopaedic Studies, Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215
- Harvard Medical School, Boston, MA 02115
| | - Andrew E. Rosenberg
- Department of Pathology, Massachusetts General Hospital, Boston, MA 02114
- Harvard Medical School, Boston, MA 02115
| | - Rosalynn M. Nazarian
- Department of Pathology, Massachusetts General Hospital, Boston, MA 02114
- Harvard Medical School, Boston, MA 02115
| | | | - Guangping Dai
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129
- Harvard Medical School, Boston, MA 02115
| | - Dionyssios Mintzopoulos
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129
- Harvard Medical School, Boston, MA 02115
| | - Yaotang Wu
- Department of Orthopaedic Surgery, Children’s Hospital, Boston, MA 02115
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129
- Harvard Medical School, Boston, MA 02115
- Corresponding Author: Yaotang Wu, Department of Orthopaedic Surgery, Children’s Hospital, Room 930, Enders Building, 300 Longwood Avenue, Boston, MA 02115, Phone: 617-919-2060, Fax: 617-730-0122,
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7
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Hyperphosphatemia-induced hyperparathyroidism in 5/6 nephrectomized rats: development of a new animal model. Chin Med J (Engl) 2008. [DOI: 10.1097/00029330-200812010-00015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Oste L, Behets GJ, Dams G, Bervoets AR, Marynissen RL, Geryl H, Van Hoof VO, De Broe ME, D'Haese PC. Role of dietary phosphorus and degree of uremia in the development of renal bone disease in rats. Ren Fail 2008; 29:1-12. [PMID: 17365904 DOI: 10.1080/08860220601038637] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
The remnant kidney rat model has been extensively used for the evaluation of bone changes due to uremia. The present study aimed to assess the effect of the dietary phosphorus availability and of the severity of renal failure on bone histomorphometric changes and various biochemical markers over time in this model. Chronic renal failure (CRF) was induced in male Wistar rats by 5/6th nephrectomy. Half of the number of animals received a standard rat diet (STD) (0.67% P, containing low bioavailable phosphorus of plant origin); the other animals were fed a high phosphorus diet (HPD) (0.93% P, containing inorganic phosphorus with high bioavailability). Every two weeks, blood and urine samples were collected. At sacrifice after 6 or 12 weeks, bone samples were taken for the measurement of histological and histodynamic parameters. Serum creatinine measurements indicated the development of mild to moderate renal failure in both diet groups. Phosphaturia was unexpectedly low in all animals that received the STD, indicating relative phosphorus depletion despite the normal dietary phosphorus content. In the HPD CRF group, a decrease in calcemia and a rise in phosphatemia were seen after 12 weeks of CRF, which were more pronounced in animals with higher serum creatinine. Serum iPTH levels were distinctly increased in CRF rats fed a HPD, especially those with more pronounced renal failure. Serum osteocalcin and to a lesser extend tartrate-resistant acid phosphatase and urinary pyridinoline and deoxypyridinoline crosslinks were higher in the CRF animals compared to the shams, particularly in the animals of the HPD group with more pronounced CRF. In both diet groups, the CRF animals had significantly higher amounts of osteoid compared to shams. Only the animals that received a HPD developed distinct histological signs of secondary hyperparathyroidism (sHPTH), that is, an increased bone formation rate, mineral apposition rate, osteoblast perimeter, and eroded perimeter. Again, this effect was most prominent in rats with more severe CRF. In conclusion, data of the present study indicate that in experimental studies using the remnant kidney rat model, both the dietary phosphorus bioavailability and the degree of renal failure in the development of hyperparathyroidism should be considered.
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Affiliation(s)
- Line Oste
- Laboratory of Pathophysiology, Antwerp University, Belgium
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Jokihaara J, Pörsti IH, Kööbi P, Jolma PM, Mustonen JT, Saha HHT, Sievänen H, Kannus P, Iwaniec UT, Turner RT, Järvinen TLN. Treatment of experimental renal osteodystrophy with pamidronate. Kidney Int 2008; 74:319-27. [PMID: 18463610 DOI: 10.1038/ki.2008.180] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We evaluated the effects of the bisphosphonate pamidronate on bone histomorphometry, structure and strength in male rats with uninephrectomy or with chronic renal disease induced by 5/6 nephrectomy. In rats with chronic renal disease the plasma urea, phosphate and parathyroid hormone levels were significantly increased compared to rats with a uninephroctomy and none of these parameters was affected by pamidronate treatment. In the femoral midshaft, chronic renal disease reduced cortical bone mineral density and content. No difference was observed in the breaking load of the femoral midshaft. In the distal femur, a high-turnover renal osteodystrophy was found but pamidronate suppressed this bone turnover and increased bone mineral content. Treatment had no effect on chronic disease-induced augmentation of osteoid volume or fibroblast surface. These studies show that in this model of stage 3 renal disease, pamidronate increased mineral content in the femoral midshaft and distal metaphysis primarily by adding bone to endocortical and trabecular surfaces but did not reduce osteitis fibrosa.
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Affiliation(s)
- Jarkko Jokihaara
- Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada
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10
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Jokihaara J, Järvinen TLN, Jolma P, Kööbi P, Kalliovalkama J, Tuukkanen J, Saha H, Sievänen H, Kannus P, Pörsti I. Renal insufficiency-induced bone loss is associated with an increase in bone size and preservation of strength in rat proximal femur. Bone 2006; 39:353-60. [PMID: 16584934 DOI: 10.1016/j.bone.2006.01.157] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Revised: 01/30/2006] [Accepted: 01/30/2006] [Indexed: 11/29/2022]
Abstract
Chronic renal insufficiency (CRI) results in phosphate retention and secondary hyperparathyroidism, the treatment of which is largely based on the use of calcium salts as phosphate binders. Advanced CRI causes bone fragility, but information about bone geometry and strength in moderate CRI is scarce. We assigned 39 8-week-old male Sprague-Dawley rats to sham-operation (Sham) or 5/6 nephrectomy (NTX). Four weeks later, the rats were randomized to 0.3% calcium (Sham, NTX) or 3.0% calcium diet (Sham + Calcium, NTX + Calcium). After 8 weeks, the animals were sacrificed, plasma samples collected, and femora excised for neck and midshaft analyses: dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and biomechanical testing. The NTX increased plasma urea and PTH 1.6-fold and 3.6-fold, respectively, whereas high calcium intake suppressed PTH to 30% of controls. Total femoral bone mineral content decreased (-6.3%) in the NTX group, while this deleterious effect was reversed by high calcium diet. In the site-specific analysis of the femoral neck, the volumetric bone density (-6.5%) was decreased in the NTX group but not NTX + Calcium group. However, in the nephrectomized rats, there was also a concomitant increase in the cross-sectional area (+15%), and, despite the decrease in bone density, the mechanical strength of the femoral neck was maintained. In the midshaft, NTX decreased cortical volumetric bone density (-1.2%), but similar to the femoral neck, no differences were found in the mechanical strength. In conclusion, a decrease in bone mass in moderate experimental CRI was associated with a concomitant increase in bone size, and maintenance of mechanical competence. Although high calcium diet suppressed plasma PTH to under normal physiological levels, it prevented the CRI-induced loss of bone mass without an adverse influence on bone strength.
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MESH Headings
- Absorptiometry, Photon
- Animals
- Biomechanical Phenomena
- Blood Urea Nitrogen
- Bone Resorption/diagnostic imaging
- Bone Resorption/etiology
- Bone and Bones/anatomy & histology
- Bone and Bones/diagnostic imaging
- Calcium/blood
- Calcium, Dietary/administration & dosage
- Calcium, Dietary/pharmacology
- Creatinine/blood
- Femur/diagnostic imaging
- Femur/drug effects
- Femur/physiology
- Hydrogen-Ion Concentration
- Hyperparathyroidism, Secondary/blood
- Hyperparathyroidism, Secondary/etiology
- Hyperparathyroidism, Secondary/physiopathology
- Nephrectomy
- Parathyroid Hormone/blood
- Phosphates/blood
- Random Allocation
- Rats
- Rats, Sprague-Dawley
- Renal Insufficiency, Chronic/etiology
- Renal Insufficiency, Chronic/physiopathology
- Tomography, X-Ray Computed
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Affiliation(s)
- Jarkko Jokihaara
- Medical School and the Institute of Medical Technology, University of Tampere, Tampere, Finland
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Padagas J, Colloton M, Shalhoub V, Kostenuik P, Morony S, Munyakazi L, Guo M, Gianneschi D, Shatzen E, Geng Z, Tan HL, Dunstan C, Lacey D, Martin D. The receptor activator of nuclear factor-kappaB ligand inhibitor osteoprotegerin is a bone-protective agent in a rat model of chronic renal insufficiency and hyperparathyroidism. Calcif Tissue Int 2006; 78:35-44. [PMID: 16362459 DOI: 10.1007/s00223-005-0161-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Accepted: 09/09/2005] [Indexed: 11/25/2022]
Abstract
Osteoprotegerin (OPG) acts by neutralizing the receptor activator of nuclear factor-kappaB ligand (RANKL), the primary mediator of osteoclast differentiation, function, and survival. We examined whether OPG could affect the bone loss associated with chronic kidney disease (CKD) in a rodent model of CKD and secondary hyperparathyroidism (SHPT). SHPT was induced in rats by 5/6 nephrectomy (5/6 Nx) and a 1.2% P/0.6% Ca(2+) diet. Starting 1 week after 5/6 Nx, rats were treated with vehicle (veh) or OPG-Fc (3 mg/kg, intravenously) every 2 weeks for 9 weeks. At baseline, 3, 6, and 9 weeks, blood was taken and bone mineral density (BMD) and bone mineral content (BMC) were assessed by dual-energy X-ray absorptiometry. Serum parathyroid hormone (sPTH) levels reached 912 pg/ml in 5/6 Nx rats vs. 97 pg/ml in shams at 9 weeks. OPG-Fc had no effect on sPTH or Ca(2+) levels throughout the 9-week study, indicating that SHPT was a renal effect independent of bone changes. At 3 weeks, 5/6 Nx-veh rats had osteopenia compared with sham-veh rats and 5/6 Nx-OPG-Fc rats had significantly higher percent changes in whole-body BMC, leg BMD, and lumbar BMD versus 5/6 Nx-veh rats. By 6-9 weeks, elevated sPTH was associated with reversal of bone loss and osteitis fibrosa in the proximal tibial metaphysis. OPG-Fc decreased this sPTH-driven high bone turnover, resulting in augmented thickness of proximal tibial trabeculae in 5/6 Nx rats. Thus, RANKL inhibition with OPG-Fc can block the deleterious effects of continuously elevated sPTH on bone, suggesting that RANKL may be an important therapeutic target for protecting bone in patients with CKD and SHPT.
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MESH Headings
- Absorptiometry, Photon
- Animals
- Carrier Proteins/antagonists & inhibitors
- Disease Models, Animal
- Glycoproteins/antagonists & inhibitors
- Glycoproteins/genetics
- Glycoproteins/metabolism
- Humans
- Hyperparathyroidism/etiology
- Hyperparathyroidism/metabolism
- Hyperparathyroidism/pathology
- Kidney Failure, Chronic/complications
- Kidney Failure, Chronic/metabolism
- Male
- Membrane Glycoproteins/antagonists & inhibitors
- Osteoprotegerin
- Parathyroid Hormone/blood
- RANK Ligand
- Rats
- Rats, Sprague-Dawley
- Receptor Activator of Nuclear Factor-kappa B
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Tumor Necrosis Factor/antagonists & inhibitors
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/metabolism
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Affiliation(s)
- J Padagas
- Department of Metabolic Disorders, Amgen Inc, One Amgen Center Drive, Thousand Oaks, CA 91320, USA
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12
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13
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Brkovic D, Linke J, Jakse G, Bauss F. Changes in bone structure after augmentation cystoplasty in chronic uraemic rats. BJU Int 2005; 95:1066-70. [PMID: 15839934 DOI: 10.1111/j.1464-410x.2005.05468.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To investigate the effect of urinary diversion using several types of intestinal segments on cortical and cancellous bone structure of growing rats with renal insufficiency. MATERIAL AND METHODS In all, 110 female Sprague-Dawley rats (8 weeks old) had either a two-stage subtotal nephrectomy by removing five-sixths of the renal mass, or a sham operation. Except for a uraemic control group, all uraemic rats then had an enterocystoplasty using stomach, ileum or colon (20 animals per group). An additional group with colic augmentation received the bisphosphonate ibandronate. After 12 weeks, the left tibia was assessed using peripheral quantitative computed tomography and bone histomorphometry. RESULTS After subtotal nephrectomy all groups had approximately 30% less endogenous creatinine clearance. Renal failure alone or in association with gastric or colic augmentation induced only negligible changes in the mass and structure of cortical and cancellous tibial bone. In contrast, rats after ileal augmentation and renal failure had a significant reduction in cancellous bone mineral density (P < 0.05) whereas the reduction in trabecular bone area and volume was not statistically significant. Furthermore, ileocystoplasty caused a decrease in trabecular number and perimeter, increased trabecular separation and enlarged bone marrow space, whereas ileocystoplasty had no effect on cortical bone. The changes were not associated with alterations in serum pH. Ibandronate treatment in the colonic cystoplasty group increased trabecular bone mass and structural variables over the untreated colonic cystoplasty group. CONCLUSIONS These results suggest that cystoplasty using an ileal segment causes a decrease in bone mass and architecture in growing rats with mild uraemia. It remains open to question whether the results obtained from experimental animals can be directly extrapolated to the clinical situation.
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Affiliation(s)
- Drasko Brkovic
- Department of Urology, University Hospital of Aachen, Aachen, Germany.
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14
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Faibish D, Gomes A, Boivin G, Binderman I, Boskey A. Infrared imaging of calcified tissue in bone biopsies from adults with osteomalacia. Bone 2005; 36:6-12. [PMID: 15663997 DOI: 10.1016/j.bone.2004.08.019] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2004] [Revised: 07/13/2004] [Accepted: 08/24/2004] [Indexed: 10/26/2022]
Abstract
Osteomalacia is a pathological bone condition in which there is deficient primary mineralization of the matrix, leading to an accumulation of osteoid tissue and reduced bone mechanical strength. The hypothesis that there are no qualitative or quantitative differences in osteomalacic bone mineral or matrix compared to disease-free bones was tested by examining unstained sections of polymethyl methacrylate (PMMA) embedded iliac crest biopsies using Fourier transform infrared imaging (FTIRI) at approximately 6-microm spatial resolution. Controls were seven female subjects, aged 36-57, without apparent bone disease. The experimental group consisted of 11 patients aged 22-72, diagnosed with osteomalacia. The spectroscopic parameters analyzed in each data set were previously established as sensitive to bone quality: phosphate/amide I band area ratio (mineral content), 1660/1690 cm(-1) peak ratio (collagen cross-links), and the 1030/1020 cm(-1) peak ratio (mineral crystallinity). The correspondence between spectroscopic mineral content (phosphate/amide I ratio) and ash weight was validated for apatite crystals of different composition and crystallite size. The FTIRI results from the biopsies expressed as color-coded images and pixel population means were compared with the nonparametric Mann-Whitney U test. There were no significant differences in the cortical parameters. Significant difference was found in the mineral content of the trabecular regions with a lower mean value in osteomalacia (P = 0.01) than in controls. Mineral crystallinity tended to be decreased in the trabecular bone (P = 0.09). This study supports the hypothesis that, in osteomalacia, the quality of the organic matrix and of mineral in the center of bone does not change, while less-than-optimal mineralization occurs at the bone surface. This study provides the first spectroscopic evaluation of whole bone mineral and matrix properties in osteomalacia, demonstrating that there are few differences in collagen cross-links between biopsies from patients with osteomalacia and from individuals without histological evidence of bone disease.
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Affiliation(s)
- Dan Faibish
- Hospital for Special Surgery, New York, NY 10021, USA
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15
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Brkovic D, Seibel M, Juchem R, Linke J, Rohde D, Bauss F. Effect of Augmentation Cystoplasty on Bone Metabolism in Chronic Uremic Rats. J Urol 2004; 171:921-5. [PMID: 14713854 DOI: 10.1097/01.ju.0000104561.90514.cb] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE We examined the impact of urinary diversion using several types of intestinal segments on the bone metabolism of growing rats with renal insufficiency. MATERIALS AND METHODS A total of 110, 8-week-old Sprague-Dawley rats underwent 2-stage subtotal nephrectomy by removal of 5/6 of the renal mass or sham operation. Except for a uremic control group all uremic rats underwent enterocystoplasty using stomach, ileum or colon. An additional group with colic augmentation received the bisphosphonate ibandronate. Bone mineral density of the tibia and lumbar spine, serum analysis and urinary excretion of the bone resorption marker deoxypyridinoline were determined monthly for 12 weeks. At study termination bone ash weight, bone mineral analysis and serum osteotropic hormone levels were determined. RESULTS All groups undergoing subtotal nephrectomy had a decreased endogenous creatinine clearance of approximately 30%. The lowest gains in tibial and lumbar spine bone mineral density were observed in animals undergoing ileocystoplasty. Femoral calcium content was significantly decreased in uremic ileocystoplasty rats compared with uremic controls. These changes were not induced by alterations in serum pH, nor were they associated with accelerated bone resorption as assessed by deoxypyridinoline. Ibandronate prevented changes related to bone resorption and increased bone mass. CONCLUSIONS Our results suggest that cystoplasty using ileum segments can aggravate renal bone disease in growing rats with mild uremia. Since the acid-base state was unchanged, other properties of the interposed ileum segment must be responsible for the negative effect on bone metabolism.
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Affiliation(s)
- Drasko Brkovic
- Department of Urology, University Hospital of Aachen, Germany.
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16
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Gordeladze JO, Drevon CA, Syversen U, Reseland JE. Leptin stimulates human osteoblastic cell proliferation, de novo collagen synthesis, and mineralization: Impact on differentiation markers, apoptosis, and osteoclastic signaling. J Cell Biochem 2002; 85:825-36. [PMID: 11968022 DOI: 10.1002/jcb.10156] [Citation(s) in RCA: 276] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Anabolic hormones, mechanical loading, and the obese protein leptin play separate roles in maintaining bone mass. We have previously shown that leptin, as well as its receptor, are expressed by normal human osteoblasts. Consequently, we have investigated how leptin affects proliferation, differentiation, and apoptosis of human osteoblasts. Iliac crest osteoblasts, incubated with either leptin (100 ng/ml), calcitriol (1,25(OH)(2)D(3); 10(-9) M) or 1-84 human parathyroid hormone (PTH; 10(-8) M), were cultured for 35 consecutive days and assayed for expression of various differentiation-related marker genes (as estimated by RT-PCR), de novo collagen synthesis, proliferation, in vitro mineralization, and osteoclast signaling. The effects of leptin on protection against retinoic acid (RA; 10(-7) M) induced apoptosis, as well as transition into preosteocytes, were also tested. Leptin exposure enhanced cell proliferation and collagen synthesis over both control condition and PTH exposure. Leptin inhibited in vitro calcified nodule production after 1-2 weeks in culture, however, subsequent to 4-5 weeks, leptin significantly stimulated mineralization. The mineralization profile throughout the entire incubation period was almost undistinguishable from the one induced by PTH. In comparison, 1,25(OH)(2)D(3) generally reduced proliferation and collagen production rates, whereas mineralization was markedly enhanced. Leptin exposure (at 2 and 5 weeks) significantly enhanced the expression of TGFbeta, IGF-I, collagen-Ialpha, ALP, and osteocalcin mRNA. Leptin also protected against RA-induced apoptosis, as estimated by soluble DNA fractions and DNA laddering patterns subsequent to 10 days of culture. The expression profiles of Bax-alpha and Bcl-2 mRNAs indicated that leptin per se significantly protected against apoptosis throughout the entire incubation period. Furthermore, the osteoblast marker OSF-2 was diminished, whereas the CD44 osteocyte marker gene expression was stimulated, indicating a transition into preosteocytes. In terms of osteoclastic signaling, leptin significantly augmented the mRNA levels of both interleukin-6 (IL-6) and osteoprotegerin (OPG). In summary, continuous leptin exposure of iliac crest osteoblasts, promotes collagen synthesis, cell differentiation and in vitro mineralization, as well as cell survival and transition into preosteocytes. Leptin may also facilitate osteoblastic signaling to the osteoclast.
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Affiliation(s)
- Jan O Gordeladze
- Department of Medical Biochemistry, University of Oslo, Oslo, Norway.
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Reseland JE, Syversen U, Bakke I, Qvigstad G, Eide LG, Hjertner O, Gordeladze JO, Drevon CA. Leptin is expressed in and secreted from primary cultures of human osteoblasts and promotes bone mineralization. J Bone Miner Res 2001; 16:1426-33. [PMID: 11499865 DOI: 10.1359/jbmr.2001.16.8.1426] [Citation(s) in RCA: 233] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The adipose hormone leptin and its receptor are important for regulation of food intake and energy metabolism. Leptin also is involved in the growth of different tissues. In this study, we show the expression of leptin in primary cultures of normal human osteoblasts (hOBs) as evidenced by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunocytochemistry. Release of leptin into the medium also was found. Leptin was not detected in commercially available hOBs (NHOst) or in three different human monoclonal osteosarcoma cell lines. Leptin expression was observed in OBs in the mineralization and/or the osteocyte transition period but not during the matrix maturation period. Furthermore, hOBs and osteosarcoma cell lines expressed the long signal-transducing form of the leptin receptor (OB-Rb) as shown by RT-PCR. We observed no significant changes in leptin or OB-Rb genes in hOBs after incubation with recombinant leptin, indicating no autoregulation of the leptin expression. Incubation of both hOBs entering the mineralization phase and osteosarcoma cell lines with recombinant leptin markedly increased the number of mineralized nodules as shown by alizarin S staining. These findings indicate that leptin may be of importance for osteoblastic cell growth and bone mineralization.
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Affiliation(s)
- J E Reseland
- Institute for Nutrition Research, University of Oslo, Norway
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Schrooten I, Cabrera W, Goodman WG, Dauwe S, Lamberts LV, Marynissen R, Dorriné W, De Broe ME, D'Haese PC. Strontium causes osteomalacia in chronic renal failure rats. Kidney Int 1998; 54:448-56. [PMID: 9690211 DOI: 10.1046/j.1523-1755.1998.00035.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND We recently reported an association between increased bone strontium (Sr) levels and osteomalacia in dialysis patients. METHODS To delineate whether or not Sr acts as a causal factor in the development of osteomalacia, we devised the following study: four groups of chronic renal failure (CRF) rats were given Sr, aluminum (Al), both of these compounds or none of the elements (controls). RESULTS Administration of Sr and/or A1 resulted in increased bone levels of the respective elements. Histological examination revealed impairment of mineralization in the Sr group and to a lesser extent in the Al group as compared to the control group. There was also a significant increase in osteoid area in the Sr group, but not in the Al group. No differences in bone surface or erodic perimeter were noted between the various study groups. Histochemically, Sr could be localized in calcified bone, mainly in new bone close to the osteoid/calcification front, a critical site of bone mineralization. Histochemical findings were confirmed by electron probe X-ray microanalysis. CONCLUSIONS These findings indicate that Sr accumulation in chronic renal failure rats resulted in the development of osteomalacic lesions, in contrast to the Al group where adynamic bone disease was induced in the present set-up. Further studies are required to define the mechanism by which way Sr causes osteomalacia in chronic renal failure rats.
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Affiliation(s)
- I Schrooten
- Department of Nephrology, University of Antwerp, Belgium
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Wada M, Ishii H, Furuya Y, Fox J, Nemeth EF, Nagano N. NPS R-568 halts or reverses osteitis fibrosa in uremic rats. Kidney Int 1998; 53:448-53. [PMID: 9461105 DOI: 10.1046/j.1523-1755.1998.00782.x] [Citation(s) in RCA: 126] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Osteitis fibrosa is a common bone injury associated with secondary hyperparathyroidism (2(o)HPT). NPS R-568 is a phenylalkylamine derivative that acts as an agonist at the cell-surface Ca2+ receptor ("calcimimetic") and inhibits parathyroid hormone (PTH) secretion. In the present study, we tested whether NPS R-568 could ameliorate osteitis fibrosa in partially nephrectomized (Nx) rats with 2(o)HPT. Six months after surgery, Nx rats had developed mild but progressive 2(o)HPT and osteitis fibrosa. Two groups of Nx rats received NPS R-568 (3 and 30 mg/kg body wt x day) by daily gavage for 30 days, which led to a dose-related decrease in serum PTH levels and to a marked reduction in peritrabecular fibrosis (0.96 +/- 0.49% to < 0.1%). Furthermore, 2(o)HPT was associated with decreases in volumetric cortical bone mineral density (vCtBMD) and in cortical bone stiffness at the femoral midshaft. NPS R-568 significantly restored the deficits in vCtBMD and stiffness. These results indicate that NPS R-568 has beneficial effects on bones with osteitis fibrosa by normalizing serum PTH levels.
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Affiliation(s)
- M Wada
- Pharmaceutical Research Laboratory and Pharmaceutical Development Laboratory, Kirin Brewery Co., Ltd., Gunma, Japan
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Jablonski G, Klem KH, Danielsen CC, Mosekilde L, Gordeladze JO. Aluminium-induced bone disease in uremic rats: effect of deferoxamine. Biosci Rep 1996; 16:49-63. [PMID: 8861540 DOI: 10.1007/bf01201001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We have previously established a rat model of chronic uremia, which is suitable to investigate the effect of various treatment modalities on renal osteodystrophy [1]. After four months subsequent to 5/6 nephrectomy, some animals were treated by gavage for 9 weeks with tap water (controls), or with aluminium (Al-citrate) 3 x 25 mg/week/kg b.wt +/- subsequent deferoxamine (DFO) 3 x 50 mg/week/kg b.wt. for 4 weeks. At termination of the study, serum clinical chemistry, femoral chemical composition and mechanical properties, calvarial parathyroid hormone (PTH)-elicited adenylate cyclase (AC) and phospholipase C (PLC) activities, cross-sectional femoral area, as well as bone histomorphometry, were analyzed. Animals given Al displayed moderately enhanced serum Al and bone Al accumulation, however, DFO-treatment did not fully alleviate bone Al retainment. A small increase in serum PTH was seen in all animals rendered uremic. Furthermore, a marked fall in serum alkaline phosphatase (ALP) below normal controls was observed in Al +/- DFO-treated animals compared with uremic controls. The uremic condition led to reduced femoral ratios of hydroxyproline (HYP) over Ca(2+) and phosphate (P(i)), while Al-intoxication alone enhanced femoral Hyp contents above values seen for normal controls. The protracted ureamia caused a deterioration of long bone resilience and brittleness, however, Al +/- DFO-treatment seemed to normalize the latter. Contrastingly, Al +/- DFO-gavage enhanced time to fracture. Uremic rats intoxicated with Al showed a complete loss of calvarial PTH-sensitive AC and PLC activities. DFO-treatment normalized PTH-elicited PLC, while PTH-susceptible AC remained super-normal. Al apparently exerts a long term down-regulation of both PTH-sensitive signaling systems as evidenced by studies of rat UMR 106 osteosarcoma cells in culture. The uremic condition enhanced endosteal bone resorption as shown by femoral shaft dimension analysis, while Al +/- DFO-treatment insignificantly reversed the condition. Finally, histomorphometrical analyses showed that DFO-administration tended to normalize aberrant trabecular bone volume, while rectifying both bone resorption and degree of mineralization. In conclusion, we assert that Al-intoxication hampers both processes (i.e. formation and resorption) of bone turnover, and that DFO-treatment to a certain extent prevents the uremia- and Al-induced bone disease in rats.
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Affiliation(s)
- G Jablonski
- Institute for Surgical Research, The National Hospital, Rikshospitalet, Oslo, Norway
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Jablonski G, Mortensen BM, Klem KH, Mosekilde L, Danielsen CC, Gordeladze JO. Vitamin D3 analogs and salmon calcitonin partially reverse the development of renal osteodystrophy in rats. Calcif Tissue Int 1995; 57:385-91. [PMID: 8564802 DOI: 10.1007/bf00302075] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have previously established an uremic rat model which is suitable for investigating the effect of various treatment modalities on the progression of renal osteodystrophy [1]. Four months subsequent to 5/6 nephrectomy, animals were treated three times a week for 3 months with either vehicle, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], 1,25(OH)2D3 + 24,25-dihydroxyvitamin D3 [24,25(OH)2D3], 1,25(OH)2D3 + calcitonin (CT), or 1,25(OH)2D3 + 24,25(OH)2D3 + CT. At termination of the study, clinical chemistry, chemical composition, and mechanical properties of femurs, calvarial parathyroid hormone (PTH)-elicited adenylate cyclase (AC), and phospholipase C (PL-C) activities, femoral cross-sectional area, and bone histomorphometry were analyzed. The main findings were that 1,25(OH)2D3 +/- 24,25(OH)2D3 treatment enhanced elasticity as well as time to fracture at the femoral metaphysis. CT potentiated the increase in elasticity obtained by 1,25(OH)2D3 +/- 24,25(OH)2D3 treatment. Only 24,25(OH)2D3 administration rectified the supernormal PTH-stimulated uremic bone AC, and only 1,25(OH)2D3 medication normalized the diminished CT-elicited AC. The obliterated uremic bone PTH-sensitive PL-C was fully normalized by all drug regimens. Femoral shaft inner zone diameter was enhanced by uremia, however, all drug treatments normalized it. Ditto effect was registered with either drug treatment on the subnormal outer and inner zone widths. Histomorphometrical analyses showed that 1,25(OH)2D3 administration reduced both eroded and osteoid surfaces. Most prominently, adjuvant 24,25(OH)2D3 or CT administration potentiated the beneficial effect of 1,25(OH)2D3 on fibrosis and osteomalacia. We assert that vitamin D3 treatment markedly reverses the development of renal osteodystrophy, and CT potentiates the effect of vitamin D3.
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Affiliation(s)
- G Jablonski
- Institute for Surgical Research, National Hospital, Rikshospitalet, Oslo, Norway
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Mortensen BM, Lund HW, Jablonski G, Paulssen RH, Gordeladze JO. Direct effects of vitamin D3 analogues on G-protein mediated signalling systems in rat osteosarcoma cells and rat pituitary adenoma cells. Biosci Rep 1995; 15:135-50. [PMID: 7579039 DOI: 10.1007/bf01207454] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In normal rats treated with 1,25(OH)2D3 or 24,25(OH)2D3, serum Ca2+, ALP, PRL and GH are significantly altered. In order to study the primary effect of vitamin D3 analogues on target organ function, rat UMR 106 osteosarcoma and GH3 pituitary adenoma cells in monolayer culture were exposed accordingly. Surprisingly, prolonged exposure of these cell lines to physiological levels of either 1,25(OH)2D3 or 24,25(OH)2D3 did not significantly affect the secretory parameters (ALP, PRL or GH) tested. However, 1,25(OH)2D3 exposure significantly reduced PTH- and Gpp(NH)p-elicited AC as well as Gpp(NH)p-stimulated PLC activities in the UMR 106 cells. These changes were accompanied by an increase and decrease in the membrane contents of the G-protein subunits G36 beta and Gq/11 alpha, respectively. In contrast, 24,25(OH)2D3 remained without significant biological effect on these signalling systems despite concomitantly augmented levels of G36 beta. TRH- and Gpp(NH)p-elicited PLC activities in the GH3 cells were significantly reduced by 1,25(OH)2D3 with a concurrent reduction in cellular amounts of Gq/11 alpha, however, 24,25(OH)2D3 did not significantly alter any signalling systems nor G-proteins analyzed. It is concluded that the osteoblastic and pituitary cell secretion of ALP, PRL and GH remain unaffected by the presence of 1,25(OH)2D3 and 24,25(OH)2D3, despite distinct alterations in components of G-protein mediated signalling pathways. Hence, other factors like ambient Ca2+ may be responsible for the perturbed secretory patterns of ALP and PRL seen in vitamin D3 treated rats.
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Affiliation(s)
- B M Mortensen
- Institute of Medical Biochemistry, University of Oslo, Norway
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Jablonski G, Danielsen CC, Mosekilde L, Gordeladze JO. Surgically induced uremia in rats. II: Osseous PTH-susceptible signaling systems as predictors of bone resorption. Calcif Tissue Int 1994; 55:281-7. [PMID: 7820779 DOI: 10.1007/bf00310407] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Predicting the course of parathormone (PTH)-elicited bone turnover in both humans and experimental rat models with moderate chronic uremia, using only standard clinical chemistry analyses, is often difficult. Consequently, rat bone from 1 + 2/3 nephrectomized animals, after 230 days of progressive renal failure, was examined for PTH-stimulated adenylate cyclase (AC) and phospholipase C (PL-C) activities. Correlations to biological parameters related to the function of bone and kidney were made. Reduced renal function was demonstrated by increased serum creatinine; circulating 1,25 dihydroxyvitamin D3 below detection level; diminished renal PTH-elicited AC activity; and decreased urinary cAMP excretion. PTH-activated renal PL-C was also reduced. However, no significant differences were seen in urine creatinine, calcium, phosphate, and hydroxyproline, nor in serum PTH, alkaline phosphatase, calcium, and phosphate. Notwithstanding, renal osteodystrophy developed as estimated by increased plasticity of the long bones, as well as reduction of the diaphyseal (Dd) and inner femoral mid-shaft (Di) diameters. Femoral cancellous bone exhibited a substantial elevation of both eroded surface (ES) and osteoid surface (OS) as well as a marked reduction in trabecular bone volume (TBV). Calvarial PTH-activated AC was enhanced, whereas corresponding PL-C was markedly reduced. PTH-enhanced AC correlated positively with ES and negatively with Di, respectively. PTH-enhanced PL-C, however, correlated positively with bone calcium content and negatively with ES. Our results indicate that bone modeling and remodeling are to a large extent related to PTH-elicited signaling systems, and cannot easily be predicted by standard clinical chemistry analyses.
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Affiliation(s)
- G Jablonski
- Institute of Medical Biochemistry, University of Oslo, Norway
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