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Chen D, Rehfeld JF, Watts AG, Rorsman P, Gundlach AL. History of key regulatory peptide systems and perspectives for future research. J Neuroendocrinol 2023; 35:e13251. [PMID: 37053148 DOI: 10.1111/jne.13251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/10/2023] [Accepted: 02/26/2023] [Indexed: 03/06/2023]
Abstract
Throughout the 20th Century, regulatory peptide discovery advanced from the identification of gut hormones to the extraction and characterization of hypothalamic hypophysiotropic factors, and to the isolation and cloning of multiple brain neuropeptides. These discoveries were followed by the discovery of G-protein-coupled and other membrane receptors for these peptides. Subsequently, the systems physiology associated with some of these multiple regulatory peptides and receptors has been comprehensively elucidated and has led to improved therapeutics and diagnostics and their approval by the US Food and Drug Administration. In light of this wealth of information and further potential, it is truly a time of renaissance for regulatory peptides. In this perspective, we review what we have learned from the pioneers in exemplified fields of gut peptides, such as cholecystokinin, enterochromaffin-like-cell peptides, and glucagon, from the trailblazing studies on the key stress hormone, corticotropin-releasing factor, as well as from more recently characterized relaxin-family peptides and receptors. The historical viewpoints are based on our understanding of these topics in light of the earliest phases of research and on subsequent studies and the evolution of knowledge, aiming to sharpen our vision of the current state-of-the-art and those studies that should be prioritized in the future.
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Affiliation(s)
- Duan Chen
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Jens F Rehfeld
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Alan G Watts
- Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
- Florey Department of Neuroscience and Mental Health and Department of Anatomy and Physiology, The University of Melbourne, Melbourne, VIC, Australia
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Jensen VFH, Mølck AM, Dalgaard M, McGuigan FE, Akesson KE. Changes in bone mass associated with obesity and weight loss in humans: Applicability of animal models. Bone 2021; 145:115781. [PMID: 33285255 DOI: 10.1016/j.bone.2020.115781] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 11/05/2020] [Accepted: 11/27/2020] [Indexed: 12/21/2022]
Abstract
The implications of obesity and weight loss for human bone health are not well understood. Although the bone changes associated with weight loss are similar in humans and rodents, that is not the case for obesity. In humans, obesity is generally associated with increased bone mass, an outcome which is exacerbated by advanced age and menopause. In rodents, by contrast, bone mass decreases in proportion to severity and duration of obesity, and is influenced by sex, age and mechanical load. Despite these discrepancies, rodents are frequently used to model the situation in humans. In this review, we summarise the existing knowledge of the effects of obesity and weight loss on bone mass in humans and rodents, focusing on the translatability of findings from animal models. We then describe how animal models should be used to broaden the understanding of the relationship between obesity, weight loss, and skeletal health in humans. Specifically, we highlight the aspects of study design that should be considered to optimise translatability of the rodent models of obesity and weight loss. Notably, the sex, age, and nutritional status of the animals should ideally match those of interest in humans. With these caveats in mind, and depending on the research question asked, our review underscores that animal models can provide valuable information for obesity and weight-management research.
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Affiliation(s)
- Vivi F H Jensen
- Lund University, Department of Clinical Sciences Malmö and Skåne University Hospital, Department of Orthopedics, Inga Marie Nilssons Gata 22, 205 02 Malmö, Sweden.
| | - Anne-Marie Mølck
- Novo Nordisk A/S, Department of Safety Sciences, Imaging & Data Management, Novo Nordisk Park 1, 2760 Maaloev, Denmark
| | - Majken Dalgaard
- Novo Nordisk A/S, Department of Safety Sciences, Imaging & Data Management, Novo Nordisk Park 1, 2760 Maaloev, Denmark
| | - Fiona E McGuigan
- Lund University, Department of Clinical Sciences Malmö and Skåne University Hospital, Department of Orthopedics, Inga Marie Nilssons Gata 22, 205 02 Malmö, Sweden
| | - Kristina E Akesson
- Lund University, Department of Clinical Sciences Malmö and Skåne University Hospital, Department of Orthopedics, Inga Marie Nilssons Gata 22, 205 02 Malmö, Sweden
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Pantoprazole (PPZ) Inhibits RANKL-Induced Osteoclast Formation and Function In Vitro and Prevents Lipopolysaccharide- (LPS-) Induced Inflammatory Calvarial Bone Loss In Vivo. Stem Cells Int 2020; 2020:8829212. [PMID: 33354217 PMCID: PMC7737473 DOI: 10.1155/2020/8829212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 11/03/2020] [Accepted: 11/10/2020] [Indexed: 02/07/2023] Open
Abstract
Bone remodeling is a process delicately balanced between osteoclastic bone resorption and osteoblastic bone formation. Osteoclasts (OCs) are multinucleated giant cells formed through the fusion of monocytic precursors of the hematopoietic stem cells lineage. OCs are the exclusive cells responsible for the resorption and degradation of the mineralized bone matrix. Pantoprazole (PPZ), a proton pump inhibitor (PPI), is commonly prescribed to reduce excess gastric acid production for conditions such as gastroesophageal reflux disease and peptic ulcer disease. Studies have found contradictory effects of PPI therapy on bone metabolism due to the lack of understanding of the exact underlying mechanism. In this study, we found that PPZ inhibits receptor activator of nuclear factor-κB (NF-κB) ligand- (RANKL-) induced osteoclastogenesis from bone marrow monocytic/macrophage (BMMs) precursors and the bone-resorbing activity of mature OCs. Correspondingly, the expression of OC marker genes was also attenuated. At the molecular level, PPZ treatment was associated with reduced activation of the ERK MAPK signaling pathways crucial to OC differentiation. Additionally, the in vivo administration of PPZ protected mice against lipopolysaccharide- (LPS-) induced inflammatory calvarial bone erosion, as a result of the reduced number and activity of OCs on the calvarial bone surface. Although PPI use is associated with increased risk of osteoporosis and bone fractures, our study provides evidence for the direct inhibitory effect of PPZ on OC formation and bone resorption in vitro and in vivo, suggesting a potential therapeutic use of PPZ in the treatment of osteolytic disease with localized bone destruction.
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Yoon BH, Lee BS, Won H, Kim HK, Lee YK, Koo KH. Preoperative Iron Supplementation and Restrictive Transfusion Strategy in Hip Fracture Surgery. Clin Orthop Surg 2019; 11:265-269. [PMID: 31475045 PMCID: PMC6695329 DOI: 10.4055/cios.2019.11.3.265] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 03/03/2019] [Indexed: 01/22/2023] Open
Abstract
Background Hip fracture surgery (HFS) is often associated with perioperative blood loss, and it frequently necessitates transfusion. However, the hemoglobin (Hb) threshold for transfusion remains controversial in hip fracture patients. We evaluated the usefulness of the restrictive strategy and preoperative intravenous iron supplementation in HFS. Methods We retrospectively reviewed the medical records of 1,634 patients (> 60 years of age) who underwent HFS between May 2003 and June 2014 and were followed up for 1 year or more after surgery. We used the liberal transfusion strategy until May 2009 to determine the transfusion threshold; afterwards, we switched to the restrictive transfusion strategy. Patients with the restrictive transfusion strategy (restrictive group) received intravenous iron supplementation before surgery. We compared the transfusion rate, morbidity, and mortality of the restrictive group with those of the patients with the liberal transfusion strategy (liberal group). Results Preoperative intravenous iron supplementation was not associated with any adverse reactions. The transfusion rate was 65.3% (506/775) in the liberal group and 48.2% (414/859) in the restrictive group (p < 0.001). The mean hospital stay was shorter in the restrictive group (21.5 vs. 28.8 days, p < 0.001). There was no significant difference in the postoperative medical complications including myocardial infarction and cerebrovascular event. Mortality at postoperative 30, 60, and 90 days was similar between the two groups. Conclusions Our blood management protocol involving restrictive strategy combined with preoperative intravenous iron supplementation appears to be effective and safe in HFS of elderly patients.
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Affiliation(s)
- Byung-Ho Yoon
- Department of Orthopaedic Surgery, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - Beom Seok Lee
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Heejae Won
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Hyung-Kook Kim
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Young-Kyun Lee
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Kyung-Hoi Koo
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
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Fundectomy-Evoked Osteopenia in Pigs Is Mediated by the Gastric-Hypothalamic-Pituitary Axis. Exp Biol Med (Maywood) 2016; 232:1449-57. [DOI: 10.3181/0608-rm-196] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The aim of the study was to determine the effects of gastric impairment in pigs on the axial and peripheral skeletal system properties and to test the hypothesis that fundectomy-evoked osteopenia is related to disturbed gastric-hypothalamic-pituitary axis function. Forty-day-old male piglets were subjected to experimental fundectomy (FX group, n = 6) to induce osteopenia, while sham operation was performed in the controls (SHO group, n = 6). At the age of 8 months, serum samples were collected, and the animals were sacrificed to obtain lumbar vertebrae (L1–L6) and right humerus for analysis. Using quantitative computed tomography (QCT) and dual-energy x-ray absorptiometry (DEXA) methods, bone mineral density and bone mineral content of the vertebrae and humerus were measured. The compression and three-point bending tests were applied to determine mechanical properties of lumbar vertebrae and humerus, respectively. Furthermore, geometric properties of humerus were assessed. Serum concentrations of ghrelin, growth hormone (GH), insulin-like growth factor-1 (IGF-1), and selected macro- and microelements were also determined. Performed fundectomy decreased body weight in pigs by 66% compared with pair-fed sham operated pigs ( P < 0.0001). Bone weight, bone mineral density, and bone mineral content of the lumbar vertebrae and humerus were significantly decreased in the fundectomized pigs ( P < 0.01). Mechanical parameters of the lumbar spine and humerus were decreased after the fundectomy, as well. Serum concentrations of ghrelin, GH, and IGF-1 were lowered by 74.4%, 90.6%, and 54.6% in the fundectomized pigs, respectively (all P < 0.001). Moreover, the serum concentrations of calcium, magnesium, iron and copper in the fundectomized animals were significantly decreased by 15.5%, 45.3%, 26.7%, and 26.2%, respectively ( P ≤ 0.05). In conclusion, the results obtained showed that both the disturbed gastric-hypothalamic-pituitary axis function and impaired mineral metabolism are associated with development of postfundectomy osteopenia of axial and peripheral skeleton in pigs.
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Yamasaki Y, Fujimura T, Oyama K, Higashi Y, Hirose A, Tsukada T, Okamoto K, Kinoshita J, Nakamura K, Miyashita T, Tajima H, Takamura H, Ninomiya I, Fushida S, Ohta T. Effects of rabeprazole on bone metabolic disorders in a gastrectomized rat model. Biomed Rep 2016; 5:118-124. [PMID: 27330752 DOI: 10.3892/br.2016.689] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 04/27/2016] [Indexed: 11/06/2022] Open
Abstract
Proton pump inhibitors (PPIs) are frequently prescribed to patients with gastroesophageal reflux disease; however, the number of bone fractures reportedly increased in these patients. Although PPIs have been shown to inhibit the bone resorption by osteoclasts, the effect of PPIs on skeletal metabolism remains controversial. The aim of the present study was to determine the effect of the PPI rabeprazole on skeletal metabolism using gastrectomized rats. Male Wistar rats were divided into four groups: i) Sham-surgery (n=15); ii) total gastrectomy (TG) control (n=20); iii) TG plus rabeprazole (n=20); and iv) TG plus the bisphosphonate minodronic acid (n=20). Twenty-two weeks after TG, the rats were sacrificed, and bone mineral density (BMD), bone strength and markers for bone metabolism were measured. Compared with the control group (50.0±8.1%), the TG-induced decrease in BMD was significantly ameliorated in the rabeprazole group (56.5±7.5%) and the minodronic acid group (59.0±6.0%). However, rabeprazole did not improve bone strength. In conclusion, rabeprazole does not appear to exacerbate bone metabolic disorders in gastrectomized rats, but rather ameliorates the TG-induced BMD decrease.
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Affiliation(s)
- Yuki Yamasaki
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Takashi Fujimura
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Katsunobu Oyama
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Yuki Higashi
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Atsushi Hirose
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Tomoya Tsukada
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Koichi Okamoto
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Jun Kinoshita
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Keishi Nakamura
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Tomoharu Miyashita
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Hidehiro Tajima
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Hiroyuki Takamura
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Itasu Ninomiya
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Sachio Fushida
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
| | - Tetsuo Ohta
- Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, Ishikawa 920-8641, Japan
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Noreldin AE, Sogabe M, Yamano Y, Uehara M, Mahdy MAA, Elnasharty MA, Sayed-Ahmed A, Warita K, Hosaka YZ. Spatial distribution of osteoblast activating peptide in the rat stomach. Acta Histochem 2016; 118:109-17. [PMID: 26686297 DOI: 10.1016/j.acthis.2015.12.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 11/30/2015] [Accepted: 12/02/2015] [Indexed: 11/18/2022]
Abstract
Osteoblast activating peptide (OBAP) was previously reported to be expressed in the rat stomach and to have a vital role in osteogenesis, but its distribution in rat stomach has not been determined. Thus, the aim of the present study was to identify the cell types expressing OBAP in the rat stomach. The stomachs of twelve 10-to-11-week-old male Jc1:SD rats were used. Samples were collected for immunohistochemistry, immunoelectron microscopy and dot blot assay. Immunohistochemical investigation revealed that OBAP was distributed mainly in parietal cells without any expression in chief cells, X/A-like cells or enterochromaffin-like cells. Moreover, OBAP-immunopositive cells were observed mainly in the upper and lower parts of the gastric gland. Significantly high optical density of immunopositive cells was observed in the upper and lower gastric gland regions. The dot blot assay confirmed that OBAP is secreted by parietal cells and that it is present in the gastric gland lumen. Immunoelectron microscopy demonstrated that OBAP was confined to the mitochondrial inner membrane within parietal cells and that the number of mitochondria in the upper and lower parts of the gastric epithelium was significantly larger than the number in the middle part of the gastric epithelium. Based on the results, it was concluded that OBAP is mainly produced by mitochondria of parietal cells in the upper and lower parts of the gastric epithelium. Moreover, the presence of OBAP in the gastric gland lumen suggests an exocrine mechanism of release.
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Affiliation(s)
- Ahmed E Noreldin
- Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori, Japan; Department of Histology and Cytology, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | - Maina Sogabe
- Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Yoshiaki Yamano
- Department of Veterinary Biochemistry, Faculty of Agriculture, Tottori University, Tottori, Japan; Department of Basic Veterinary Science, United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Japan
| | - Masato Uehara
- Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Mohamed A A Mahdy
- Department of Basic Veterinary Science, United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Japan; Department of Anatomy and Embryology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Mohamed A Elnasharty
- Department of Histology and Cytology, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | - Ahmed Sayed-Ahmed
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | - Katsuhiko Warita
- Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Yoshinao Z Hosaka
- Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori, Japan; Department of Basic Veterinary Science, United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Japan.
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Dobrowolski P, Tomaszewska E, Kurlak P, Pierzynowski SG. Dietary 2-oxoglutarate mitigates gastrectomy-evoked structural changes in cartilage of female rats. Exp Biol Med (Maywood) 2015. [PMID: 26202375 DOI: 10.1177/1535370215595466] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Gastrectomy (Gx) leads to osteopenia/osteoporosis in humans and animals. However, little is known about the influence of Gx on the cartilage in this regard. Recent studies have demonstrated a protective effect of 2-oxoglutaric acid (2-Ox) on bone and cartilage. Hence, the purpose of this study was to investigate whether 2-Ox can mitigate eventual Gx-induced cartilage impairment. Twenty female Sprague-Dawley rats were subjected to Gx and randomly divided into two groups: Gx + 2-Ox and Gx. Another 20 rats were sham-operated (ShO) and randomly divided into two groups: ShO + 2-Ox and ShO. The daily dose of 2-Ox administered to the rats in the drinking water was 0.43 g per 100 g rat. After eight weeks, rats were euthanized and femora and tibiae were collected. Histology and histomorphometry analyses of the articular cartilage and the growth plate were done. Gx resulted in a 32% (±44.5 femur, ±35.8 tibia) decrease in overall thickness of articular cartilage in both bones (femur: ShO 279.1 ± 48.5 vs. Gx 190.2 ± 38.4 µm, tibia: ShO 222.9 ± 50.3 µm vs. Gx 151.3 ± 52.6 µm) (in some zones up to 58 ± 28.0%), and in the growth plate up to 20% (±22.4) (femur: ShO 243.0 ± 34.0 vs. Gx 207.0 ± 33.7 µm, tibia: ShO 220.0 ± 24.6 µm vs. Gx 171.1 ± 16.1 µm). Gx altered the spatial distribution of thick and thin collagen fibers, and chondrocyte shape and size. 2-Ox administration prevented the reduction in both cartilages thickness (Gx + 2-Ox: articular cartilage 265.2 ± 53.8 µm, 235.6 ± 42.7 µm, growth plate 236.7 ± 39.2 µm, 191.3 ± 16.5 µm in femur and tibia, respectively), and abolished the spatial changes in collagen distribution and structure induced by Gx. Gx affects cartilage structure and thickness, however, 2-Ox administration mitigates these effects and showed protective and stimulatory properties. Our observations suggest that dietary 2-Ox can be used to offset some of the changes in hyaline cartilage, in particular articular cartilage, following bariatric surgeries.
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Affiliation(s)
- Piotr Dobrowolski
- Department of Comparative Anatomy and Anthropology, Maria Curie-Sklodowska University, 20-033 Lublin, Poland
| | - Ewa Tomaszewska
- Department of Animal Physiology, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, 20-950 Lublin, Poland
| | - Paulina Kurlak
- Department of Comparative Anatomy and Anthropology, Maria Curie-Sklodowska University, 20-033 Lublin, Poland
| | - Stefan G Pierzynowski
- Department of Biology, Lund University, S-223 62 Lund, Sweden Department of Medical Biology, Institute of Agricultural Medicine in Lublin, 20-950 Lublin, Poland
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Genetic determination of the cellular basis of the ghrelin-dependent bone remodeling. Mol Metab 2015; 4:175-85. [PMID: 25737953 PMCID: PMC4338319 DOI: 10.1016/j.molmet.2015.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 12/31/2014] [Accepted: 01/08/2015] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVE Bone mass is maintained through a balance of bone formation and resorption. This homeostatic balance is regulated by various systems involving humoral and local factors. The discovery that the anorexigenic hormone leptin regulates bone mass via neuronal pathways revealed that neurons and neuropeptides are intimately involved in bone homeostasis. Ghrelin is a stomach-derived orexigenic hormone that counteracts leptin's action. However, the physiological role of ghrelin in bone homeostasis remains unknown. In this study, through the global knockout of ghrelin receptor (Ghsr) followed by tissue-specific re-expression, we addressed the molecular basis of the action of ghrelin in bone remodeling in vivo. METHODS We performed molecular, genetic and cell biological analyses of Ghsr-null mice and Ghsr-null mice with tissue specific Ghsr restoration. Furthermore, we evaluated the molecular mechanism of ghrelin by molecular and cell-based assays. RESULTS Ghsr-null mice showed a low bone mass phenotype with poor bone formation. Restoring the expression of Ghsr specifically in osteoblasts, and not in osteoclasts or the central nervous system, ameliorated bone abnormalities in Ghsr-null mice. Cell-based assays revealed ghrelin induced the phosphorylation of CREB and the expression of Runx2, which in turn accelerated osteoblast differentiation. CONCLUSIONS Our data show that ghrelin regulates bone remodeling through Ghsr in osteoblasts by modulating the CREB and Runx2 pathways.
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10
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Delhanty PJD, van der Velde M, van der Eerden BCJ, Sun Y, Geminn JMM, van der Lely AJ, Smith RG, van Leeuwen JPTM. Genetic manipulation of the ghrelin signaling system in male mice reveals bone compartment specificity of acylated and unacylated ghrelin in the regulation of bone remodeling. Endocrinology 2014; 155:4287-95. [PMID: 25060361 DOI: 10.1210/en.2013-2055] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Ghrelin receptor-deficient (Ghsr-/-) mice that lack acylated ghrelin (AG) signaling retain a metabolic response to unacylated ghrelin (UAG). Recently, we showed that Ghsr-deficiency affects bone metabolism. The aim of this study was to further establish the impact of AG and UAG on bone metabolism. We compared bone metabolism in Ghsr-/- (lacking only AG signaling) and ghrelin-deficient (Ghrl-/-; both AG and UAG deficient) male mice. Ghrl-/- mice had lower cortical bone mass, whereas Ghsr-/- mice had lower trabecular bone mass. This demonstrates bone compartment-specific effects of AG and a role for UAG in bone metabolism. Also, Ghrl-/- but not Ghsr-/- mice had increased bone formation rate and increased osteogenic stem cell numbers in their bone marrow. In ex vivo bone marrow cultures both AG and UAG inhibited osteoblast differentiation. This indicated that bone resorption must be increased in these mice. Accordingly, osteoclastogenesis rate was faster in bone marrow cultures from Ghsr-/- and Ghrl-/- mice, and osteoclast formation was inhibited by AG signaling and partially suppressed by UAG. In osteoblast cultures, AG markedly induced osteoprotegerin gene expression and both peptides reduced RANKL/osteoprotegerin ratio. These data describe unique cell-type specific effects of AG and UAG within a single tissue, supporting a tight and complex control of bone formation and resorption as well as a link between nutrition and bone metabolism. The balance between AG and UAG actions in the bone marrow may lead to bone compartmental-specific effects.
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Affiliation(s)
- Patric J D Delhanty
- Department of Internal Medicine (P.J.D.D., M.V.D.V., B.C.J.V.D.E., J.M.M.G., A.-J.V.D.L., J.P.T.M.V.L.), Erasmus MC, Postbus 2040, 3000 CA Rotterdam, The Netherlands; United States Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center (Y.S.) and Huffington Center on Aging, Baylor College of Medicine, Houston, Texas 77030; and Department of Metabolism and Aging (R.G.S.), The Scripps Research Institute Florida, Jupiter, Florida 33458
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11
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Iwamoto J, Sato Y, Matsumoto H. Vitamin K2 improves femoral bone strength without altering bone mineral density in gastrectomized rats. J Nutr Sci Vitaminol (Tokyo) 2014; 60:71-7. [PMID: 24975215 DOI: 10.3177/jnsv.60.71] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Gastrectomy (GX) induces osteopenia in rats. The present study examined the skeletal effects of vitamin K2 in GX rats. Thirty male Sprague-Dawley rats (12 wk old) were randomized by the stratified weight method into the following three groups of 10 animals each: sham operation (control) group; GX group; and GX+oral vitamin K2 (menatetrenone, 30 mg/kg, 5 d/wk) group. Treatment was initiated at 1 wk after surgery. After 6 wk of treatment, the bone mineral content (BMC), bone mineral density (BMD), and mechanical strength of the femoral diaphysis and distal metaphysis were determined by peripheral quantitative computed tomography and mechanical strength tests, respectively. GX induced decreases in the BMC, BMD, and ultimate force of the femoral diaphysis and distal metaphysis. Vitamin K2 did not significantly influence the BMC or BMD of the femoral diaphysis or distal metaphysis in GX rats, but attenuated the decrease in the ultimate force and increased the stiffness of the femoral diaphysis. The present study showed that administration of vitamin K2 to GX rats improved the bone strength of the femoral diaphysis without altering the BMC or BMD, suggesting effects of vitamin K2 on the cortical bone quality.
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Affiliation(s)
- Jun Iwamoto
- Institute for Integrated Sports Medicine, Keio University School of Medicine
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12
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Ueyama T, Yamamoto Y, Ueda K, Yajima A, Maeda Y, Yamashita Y, Ito T, Tsuruo Y, Ichinose M. Is gastrectomy-induced high turnover of bone with hyperosteoidosis and increase of mineralization a typical osteomalacia? PLoS One 2013; 8:e65685. [PMID: 23776526 PMCID: PMC3679169 DOI: 10.1371/journal.pone.0065685] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 04/26/2013] [Indexed: 11/19/2022] Open
Abstract
Gastrectomy (GX) is thought to result in osteomalacia due to deficiencies in Vitamin D and Ca. Using a GX rat model, we showed that GX induced high turnover of bone with hyperosteoidosis, prominent increase of mineralization and increased mRNA expression of both osteoclast-derived tartrate-resistant acid phosphatase 5b and osteocalcin. The increased 1, 25(OH)2D3 level and unchanged PTH and calcitonin levels suggested that conventional bone and Ca metabolic pathways were not involved or changed in compensation. Thus, GX-induced bone pathology was different from a typical osteomalacia. Gene expression profiles through microarray analysis and data mining using Ingenuity Pathway Analysis indicated that 612 genes were up-regulated and 1,097 genes were down-regulated in the GX bone. These genes were related functionally to connective tissue development, skeletal and muscular system development and function, Ca signaling and the role of osteoblasts, osteoclasts and chondrocytes. Network analysis indicated 9 genes (Aldehyde dehydrogenase 1 family, member A1; Aquaporin 9; Interleukin 1 receptor accessory protein; Very low density lipoprotein receptor; Periostin, osteoblast specific factor; Aggrecan; Gremlin 1; Angiopoietin-like 4; Wingless-type MMTV integration site family, member 10B) were hubs connected with tissue development and immunological diseases. These results suggest that chronic systemic inflammation might underlie the GX-induced pathological changes in bone.
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Affiliation(s)
- Takashi Ueyama
- Department of Anatomy and Cell Biology, Wakayama Medical University Graduate School of Medicine, Wakayama, Japan.
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Influence of gastrectomy on cortical and cancellous bones in rats. Gastroenterol Res Pract 2013; 2013:381616. [PMID: 23781240 PMCID: PMC3679695 DOI: 10.1155/2013/381616] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 04/15/2013] [Accepted: 04/17/2013] [Indexed: 12/16/2022] Open
Abstract
The aim of the present study was to examine the influence of gastrectomy (GX) on cortical and cancellous bones in rats. Twenty male Sprague-Dawley rats were randomized into the two groups of 10 animals each: a sham operation (control) group and a GX group. Seven weeks after surgery, the bone mineral content and density (BMC and BMD, resp.) and the mechanical strength of the femur were determined, and bone histomorphometric analyses were performed on the tibia. GX induced decreases in the BMC, BMD, ultimate force, work to failure, and stiffness of the femoral distal metaphysis and the BMC, BMD, and ultimate force of the femoral diaphysis. GX induced a decrease in cancellous bone mass, characterized by an increased osteoid thickness, osteoid surface, osteoid volume, and bone formation. GX also induced a decrease in cortical bone mass, characterized by increased endocortical bone resorption. The GX induced reductions in the bone mass and strength parameters were greater in cancellous bone than in cortical bone. The present study showed that the response of bone formation, resorption, and osteoid parameters to GX and the degree of GX-induced osteopenia and the deterioration of bone strength appeared to differ between cortical and cancellous bones in rats.
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Kopic S, Geibel JP. Gastric acid, calcium absorption, and their impact on bone health. Physiol Rev 2013; 93:189-268. [PMID: 23303909 DOI: 10.1152/physrev.00015.2012] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Calcium balance is essential for a multitude of physiological processes, ranging from cell signaling to maintenance of bone health. Adequate intestinal absorption of calcium is a major factor for maintaining systemic calcium homeostasis. Recent observations indicate that a reduction of gastric acidity may impair effective calcium uptake through the intestine. This article reviews the physiology of gastric acid secretion, intestinal calcium absorption, and their respective neuroendocrine regulation and explores the physiological basis of a potential link between these individual systems.
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Affiliation(s)
- Sascha Kopic
- Department of Surgery and Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, USA
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Liu C, Chen J, Guo Y, Yang L, Zhao C, Bai L. The expression of PTHLH in human gastric mucosa enterochromaffin-like cells. Dig Dis Sci 2011; 56:993-8. [PMID: 20844958 PMCID: PMC3059813 DOI: 10.1007/s10620-010-1375-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 07/29/2010] [Indexed: 12/29/2022]
Abstract
BACKGROUND Gastrectomy may disturb the body's mineral homeostasis, with osteopenia and osteoporosis being among the late outcomes. Parathyroid hormone-like hormone (PTHLH) was detected in rat gastric enterochromaffin-like (ECL) cells in 2005, and some researchers suggested that it was the hypothetical hormone gastrocalcin that is believed to lead to osteoporosis. AIMS Our objective was to learn whether PTHLH is expressed in human gastric ECL cells and to form a basic understanding about the relationship between PTHLH and gastrin. METHODS We collected normal human gastric mucosa specimens and serum samples from 28 patients. RESULTS RT-PCR and immunohistochemical analysis demonstrated weak expression of PTHLH in ECL cells at the RNA and protein levels. A low level of PTHLH expression was also found in the serum. Serum gastrin did have a significant positive correlation with the relative ratio of PTHLH mRNA to β-actin levels in gastric mucosa (rs=0.569, p=0.002). CONCLUSIONS This indicates that PTHLH has a low signal expression in human gastric ECL cells and that serum gastrin levels correlate with PTHLH RNA levels in gastric mucosa. Further work is needed to evaluate the functional role of PTHLH in ECL cells and to determine whether PTHLH is gastrocalcin.
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Affiliation(s)
- Cuiping Liu
- GuangDong Provincial Key Laboratory of Gastroenterology Department for Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou Road 1838, 510515 Guangzhou, Guangdong Province China
| | - Jianting Chen
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou Road 1838, 510515 Guangzhou, Guangdong Province China
| | - Yu Guo
- Department of Huiqiao Building, Nanfang Hospital, Southern Medical University, Guangzhou Road 1838, 510515 Guangzhou, Guangdong Province China
| | - Lisheng Yang
- Department of Huiqiao Building, Nanfang Hospital, Southern Medical University, Guangzhou Road 1838, 510515 Guangzhou, Guangdong Province China
| | - Chengyi Zhao
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou Road 1838, 510515 Guangzhou, Guangdong Province China
| | - Lan Bai
- Department of Huiqiao Building, Nanfang Hospital, Southern Medical University, Guangzhou Road 1838, 510515 Guangzhou, Guangdong Province China
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Śliwa E. ORIGINAL ARTICLE: 2-Oxoglutaric acid administration diminishes fundectomy-induced osteopenia in pigs. J Anim Physiol Anim Nutr (Berl) 2010; 94:e86-95. [DOI: 10.1111/j.1439-0396.2009.00985.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Isolation and characterization of a novel peptide, osteoblast activating peptide (OBAP), associated with osteoblast differentiation and bone formation. Biochem Biophys Res Commun 2010; 400:157-63. [PMID: 20709021 DOI: 10.1016/j.bbrc.2010.08.036] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Accepted: 08/10/2010] [Indexed: 11/21/2022]
Abstract
A long-standing goal in bone loss treatment has been to develop bone-rebuilding anabolic agents that can potentially be used to treat bone-related disorders. To purify and isolate a novel anabolic that acts to osteoblasts, we monitored changes in intracellular calcium concentrations ([Ca(2+)]i). We identified a novel, 24 amino-acid peptide from the rat stomach and termed this peptide osteoblast activating peptide (OBAP). Furthermore, we examined the effects of OBAP in osteoblasts. First, osteoblast differentiation markers (alkaline phosphatase [ALP], osteocalcin [OCN]) were analyzed using quantitative RT-PCR. We also examined the ALP activity in osteoblasts induced by OBAP. OBAP significantly increased the expression of osteoblast differentiation markers and the activity of ALP in vitro. Next, to address the in vivo effects of OBAP on bone metabolism, we examined the bone mineral density (BMD) of gastrectomized (Gx) rats and found that OBAP significantly increased BMD in vivo. Finally, to confirm the in vivo effects of OBAP on bone, we measured serum ALP and OCN in Gx rats and found that OBAP significantly increased serum ALP and OCN. Taken together, these results indicate that the novel peptide, OBAP, positively regulates bone formation by augmenting osteoblast differentiation. Furthermore, these results may provide a new therapeutic approach to anabolically treat bone-related disorders.
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Zhao CY, Chen JT, Yang DH, Zhong ZM, Bai L. Effects of extracts of oxyntic mucosa in rat on the biological activity of osteoblasts. Osteoporos Int 2010; 21:129-35. [PMID: 19367351 DOI: 10.1007/s00198-009-0928-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2008] [Accepted: 03/06/2009] [Indexed: 10/20/2022]
Abstract
UNLABELLED We explored the relationship between extracts of oxyntic mucosa (EOM) and the biological activity of osteoblasts in rats. We found that EOM could enhance the activity of bone formation in osteoblast. Our results suggest that EOM likely play a role in the cases of osteopenia induced by gastrectomy. INTRODUCTION Surgical removal of the stomach (gastrectomy) leads to osteopenia in animals and in humans. It was demonstrated that EOM could induce transient hypocalcaemia and stimulate an uptake of Ca(2+) into bone in rats. The main aim of this study has been to clarify whether this procedure was performed through osteoblast, which is responsible for bone formation. METHODS Osteoblasts were isolated, cultured, and identified in vitro. Preparing the rats' EOM and diluting into low, middle, and high concentrations, respectively. After osteoblasts were treated by different concentration EOMs or saline (for control), the intracytoplasm [Ca(2+)]i was measured by laser scanning confocal microscopy; the proliferation of osteoblast cells were detected with cell counting kit 8 (CCK-8); and the expressions of collagen type I and osteocalcin were assayed by reverse transcriptase polymerase chain reaction and Western blot. RESULTS EOMs were found to induce a dose-related rapid increase of intracytoplasm [Ca(2+)]i in osteoblasts and could stimulate osteoblasts to enhance proliferation and upregulate the expressions of collagen type I and osteocalcin significantly (p < 0.05) compared with the control group. CONCLUSIONS It was confirmed that EOM could stimulate osteoblasts to elevate the cytoplasm [Ca(2+)]i and promote the multiplication and the activity of bone formation in osteoblasts.
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Affiliation(s)
- C-Y Zhao
- Spinal Surgeon Department, Southern Medical University, Guangzhou, Guangdong Province, China
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Abstract
The objective of this study was to critically assess studies regarding proton pump inhibitors (PPIs) and fractures. A MEDLINE search was conducted to identify relevant articles. Three case-control studies assessed fractures and PPI use. A study of all subjects with fracture in Denmark in 2000 revealed adjusted OR=1.18 (1.12-1.43) for PPI use within the last year (hip fracture OR=1.45,1.28-1.65); no dose-response relationship was identified. A study of hip fractures in UK patients > or =50 years found adjusted OR=1.44 (1.30-1.59) for >1 year of PPIs; duration and average daily dose were significantly associated with fracture risk: adjusted OR for >1.75 times average daily dose for >1 year was 2.65 (1.80-3.90). A study of vertebral, wrist, and hip fractures in Manitoba patients > or =50 years found adjusted OR=0.99 (0.90-1.11) for > or =1 year of continuous PPI; association became significant > or =7 years (OR=1.92, 1.16-3.18). Consistency of some positive results in all studies, the dose and/or duration response in two studies, the possibility that acid inhibition may decrease calcium absorption, and association with histamine(2)-receptor antagonists in some studies support a causal association. The low magnitude of the association (ORs<2), lack of dose-response in one study, lack of association with histamine(2)-receptor antagonists in one study, lack of experimental evidence documenting a mechanism, and inability to assess potential confounding factors limit statements regarding causality. As with all medications, PPIs should be used for appropriate indications and not in higher doses or longer durations than necessary to achieve the desired outcomes.
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Kirkpantur A, Altun B, Arici M, Turgan C. Proton pump inhibitor omeprazole use is associated with low bone mineral density in maintenance haemodialysis patients. Int J Clin Pract 2009; 63:261-8. [PMID: 19196364 DOI: 10.1111/j.1742-1241.2008.01883.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVE Limited studies have shown that proton pump inhibitor (PPI) therapy may decrease bone density or insoluble calcium reabsorption through induction of hypochlorhydria. However, PPI therapy may also reduce bone resorption via inhibition of osteoclastic vacuolar proton pumps. The aim of this study was to determine whether the opposing effects of PPI therapy may cause clinically important alterations in bone mineral densitometry (BMD) parameters in maintenance haemodialysis patients. METHODS Sixty-eight maintenance haemodialysis patients were enrolled in this study. Patients were classified into two groups involving users of PPI therapy (omeprazole 20 mg/day, group 1, n = 36 patients) and non-users of acid suppression drugs (group 2, n = 32 patients). Patients had radius, hip and spine BMD assessed by dual-energy X-ray absorptiometry. RESULTS The mean duration of PPI therapy with omeprazole was 27 +/- 5 months. The users of PPI therapy had lower values of bone mineral density and T-scores at the anatomical regions than non-users of acid suppression drugs. Serum calcium and phosphate levels, calcium-phosphate product and serum intact parathormone levels and the ratio of users of vitamin D therapy were similar among groups. A mutivariable adjusted odds ratio for lower bone density associated with more than 18 months of omeprazole, when all the potential confounders were considered, was 1.31 in the proximal radius, 0.982 in the femur neck, 0.939 in the trochanter and 1.192 in the lumbal spine. CONCLUSION The present data suggest that PPI therapy should be cautiously prescribed in maintenance haemodialysis patients, especially with lower BMD values.
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Affiliation(s)
- A Kirkpantur
- Nephrology Unit, Department of Internal Medicine, Hacettepe University Faculty of Medicine, Ankara, Turkey.
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Dobrowolski PJ, Piersiak T, Surve VV, Kruszewska D, Gawron A, Pacuska P, Håkanson R, Pierzynowski SG. Dietary alpha-ketoglutarate reduces gastrectomy-evoked loss of calvaria and trabecular bone in female rats. Scand J Gastroenterol 2008; 43:551-8. [PMID: 18415747 DOI: 10.1080/00365520701824951] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Surgical removal of the stomach (gastrectomy, Gx) leads to osteopenia in animals and in humans. In the rat, Gx adversely affects calvaria and trabecular bone. alpha-Ketoglutarate (AKG) is a precursor of hydroxyproline--the most abundant amino acid in bone collagen. The purpose of this study was to investigate the effects of dietary AKG on Gx-induced osteopenia. MATERIAL AND METHODS Twenty female Sprague-Dawley rats were subjected to Gx and divided between two groups: Gx+AKG in the drinking water and Gx+Vehicle (i.e. drinking water without AKG). Another 20 rats were sham-operated and divided between two groups: Sham+AKG and Sham+Vehicle. The daily dose of AKG was 0.43 g per 100 g rat. All the rats were killed 8 weeks later and the calvariae, femora and tibiae were collected. The integrity of the calvariae was analysed planimetrically, following transillumination and photography. The bone mineral content (BMC) and bone mineral density (BMD) were measured in the right femorae and tibiae (bone densitometry), leaving the left femorae and tibiae to be analysed histomorphometrically (measurement of trabecular bone volume and trabecular fractal dimension). RESULTS Gx caused calvarial bone degradation, reduced trabecular bone (femur and tibia) and impaired trabecular architecture. In addition, Gx lowered the femoral/tibial BMC and BMD (mainly cortical bone). Dietary AKG counteracted the Gx-evoked impairment of calvaria and trabecular bone but failed to affect the BMC and the BMD in either sham- operated or Gx rats. CONCLUSIONS Gx resulted in loss of calvarial, trabecular and cortical bone in the rat. AKG counteracted the effect of Gx on calvaria and trabecular bone but not on cortical bone.
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Affiliation(s)
- Piotr J Dobrowolski
- Department of Comparative Anatomy and Anthropology, Maria Curie-Sklodowska University, Lublin, Poland
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Vestergaard P. Adverse Effects of Drugs on Bone and Calcium Metabolism/Physiology. Clin Rev Bone Miner Metab 2008. [DOI: 10.1007/s12018-007-9002-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Schweitzer DH. Mineral Metabolism and Bone Disease after Bariatric Surgery and Ways to Optimize Bone Health. Obes Surg 2008; 17:1510-6. [DOI: 10.1007/s11695-008-9431-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Kakehasi AM, Mendes CMC, Coelho LGV, Castro LP, Barbosa AJA. The presence of Helicobacter Pylori in postmenopausal women is not a factor to the decrease of bone mineral density. ARQUIVOS DE GASTROENTEROLOGIA 2007; 44:266-70. [DOI: 10.1590/s0004-28032007000300016] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2006] [Accepted: 05/10/2007] [Indexed: 11/22/2022]
Abstract
BACKGROUND: Osteoporosis affects approximately 30% of postmenopausal women. Gastrectomy, pernicious anemia, and more recently Helicobacter pylori infection, have all been implicated in the pathogenesis of osteoporosis. A reduced parietal cell mass is a common feature in these conditions. AIM: To study a possible relationship between chronic gastritis, parietal cell density of the oxyntic mucosa and bone mineral density in postmenopausal women, as chronic gastritis, Helicobacter pylori infection and osteoporosis are frequently observed in the elderly. METHODS: Fifty postmenopausal women (61.7 ± 7 years) were submitted to gastroduodenal endoscopy and bone densitometry by dual energy X-ray absorptiometry. Glandular atrophy was evaluated objectively by the determination of parietal cell density. Helicobacter pylori infection was evaluated by histology, urease test and breath test with 13C. RESULTS: Thirty-two patients (64%) presented chronic multifocal gastritis, and 20 of them (40%) showed signs of gastric mucosa atrophy. Lumbar spine osteoporosis was found in 18 patients (36%). The parietal cell density in patients with and without osteoporosis was 948 ± 188 and 804 ± 203 cells/mm², respectively. Ten osteoporotic patients (55%) and 24 non-osteoporotic patients (75%) were infected by Helicobacter pylori. CONCLUSION: Postmenopausal women with osteoporosis presented a well-preserved parietal cell density in comparison with their counterparts without osteoporosis. Helicobacter pylori infection was not different between the two groups. We concluded that neither atrophic chronic gastritis nor Helicobacter pylori seem to be a reliable risk factor to osteoporosis in postmenopausal women.
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Affiliation(s)
| | | | | | - Luiz P. Castro
- Federal University of Minas Gerais School of Medicine, Brazil
| | - Alfredo J. A. Barbosa
- Federal University of Minas Gerais School of Medicine; Federal University of Minas Gerais School of Medicine, Brazil
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van der Velde M, Delhanty P, van der Eerden B, van der Lely AJ, van Leeuwen J. Ghrelin and Bone. GHRELIN 2007; 77:239-58. [DOI: 10.1016/s0083-6729(06)77010-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Vestergaard P, Rejnmark L, Mosekilde L. Proton pump inhibitors, histamine H2 receptor antagonists, and other antacid medications and the risk of fracture. Calcif Tissue Int 2006; 79:76-83. [PMID: 16927047 DOI: 10.1007/s00223-006-0021-7] [Citation(s) in RCA: 226] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2006] [Accepted: 04/26/2006] [Indexed: 12/22/2022]
Abstract
We studied the effect of proton pump inhibitors, histamine H(2) receptor antagonists, and other types of antacid drugs on fracture risk. All cases were subjects with any fracture sustained during the year 2000 (n = 124,655). For each case, three controls (n = 373,962) matched on age and gender were randomly drawn from the background population. The primary exposure variables were use of proton pump inhibitors, histamine H(2) antagonists, and other antacid drugs. Adjustments were made for several confounders, including diagnosis of an ulcer, nonsteroidal anti-inflammatory drug use, use of histamine H(1) antagonists, stomach resection, previous fracture, and use of corticosteroids. The effect of dose was examined by stratifying for cumulated dose (defined daily dose). Use of proton pump inhibitors was associated with an increase in fracture risk for use within the last year [odds ratio (OR) = 1.18, 95% confidence interval (CI) 1.12-1.43 for overall fracture risk; OR = 1.45, 95% CI 1.28-1.65 for hip fractures; and OR = 1.60, 95% CI 1.25-2.04 for spine fractures). Histamine H(2) antagonists were associated with a decreased fracture risk if they had been used within the last year (OR = 0.88, 95% CI 0.82-0.95 for any fracture, OR = 0.69, 95% CI 0.57-0.84 for hip fractures). Other antacids were not associated with overall fracture risk but were associated with hip and spine fractures. Proton pump inhibitors appeared to be associated with a limited increase in fracture risk, in contrast to histamine H( 2 ) antagonists, which seemed to be associated with a small decrease in fracture risk. In all cases, the changes in risk estimates were small and the clinical significance was limited.
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Affiliation(s)
- P Vestergaard
- The Osteoporosis Clinic, Aarhus Amtssygehus, Aarhus University Hospital, Tage Hansens Gade 2, DK-8000, Aarhus C, Denmark.
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Bevilacqua M, Dominguez LJ, Righini V, Valdes V, Vago T, Leopaldi E, Baldi G, Barrella M, Barbagallo M. Dissimilar PTH, gastrin, and calcitonin responses to oral calcium and peptones in hypocalciuric hypercalcemia, primary hyperparathyroidism, and normal subjects: a useful tool for differential diagnosis. J Bone Miner Res 2006; 21:406-12. [PMID: 16491288 DOI: 10.1359/jbmr.051210] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2005] [Revised: 11/29/2005] [Accepted: 12/14/2005] [Indexed: 11/18/2022]
Abstract
UNLABELLED We analyzed gastrin, PTH, and calcitonin responses to oral calcium and peptones in hypocalciuric hypercalcemia, mild primary hyperparathyroidism, and normal controls. We observed diverse hormonal responses that may help in the differential diagnosis of these conditions. INTRODUCTION Hypocalciuric hypercalcemia (HH) is consequent to calcium-sensing receptor (CaSR) genetic mutations or anti-CaSR antibodies. CaSR is expressed in parathyroid tissue, thyroid C cells, and gastrin-secreting cells, where it has been suggested that on calcium and/or amino acid allosteric activation, promotes gastrin secretion. MATERIALS AND METHODS We evaluated gastrin, PTH, and calcitonin responses to oral calcium (1 g) and peptones (10 g) in 10 patients with HH (mean age, 58.5 +/- 10.3 years; F/M = 9/1), 15 patients with primary hyperparathyroidism (PH; mean age, 60.4 +/- 8.3 years; F/M = 11/4), and 30 healthy controls (mean age, 60.3 +/- 8.1 years). Statistical analyses for differences during oral loading tests were calculated with ANOVA for repeated measurements and comparisons between two groups were performed with Student's t-test. RESULTS PTH response to peptones was markedly increased in patients with PH compared with flat responses in controls and HH patients (p < 0.05). Gastrin increase after oral calcium was absent in HH and PH subjects (p < 0.05 versus controls), and gastrin responses to peptones were blunted in HH and PH subjects compared with controls (p < 0.05). PTH drop and calcitonin increase after calcium load observed in controls were absent in HH and PH subjects (p < 0.05). CONCLUSIONS The marked difference in PTH response elicited by peptones observed in PH compared with subjects with HH may help in the differential diagnosis of these conditions without genetic studies. Peptones may stimulate CaSR-controlled hormones as an allosteric regulatory pathway. CaSR abnormalities may help to explain the different calcium- and peptones-induced hormonal responses observed in PH and HH compared with normal subjects.
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Affiliation(s)
- Maurizio Bevilacqua
- Endocrinology and Diabetes Unit, Department of Medicine, Luigi Sacco Hospital (Vialba), University of Milan, Milan, Italy.
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Andersson N, Skrtic SM, Håkanson R, Ohlsson C. A gene expression fingerprint of mouse stomach ECL cells. Biochem Biophys Res Commun 2005; 332:404-10. [PMID: 15896709 DOI: 10.1016/j.bbrc.2005.05.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2005] [Accepted: 05/02/2005] [Indexed: 12/28/2022]
Abstract
Many of the endocrine cells in the stomach are poorly characterized with respect to physiological significance. In some cases, the anticipated hormone has not yet been identified. Global gene expression analysis of mouse stomach was performed in an attempt to identify the ECL-cell peptide/protein. Specific functional activation (omeprazole-induced hypergastrinaemia) was used as a tool to generate a gene expression fingerprint of the ECL cells. The proposed fingerprint includes 14 genes, among them six are known to be expressed by ECL cells (=positive controls), and some novel ones, which are likely to be ECL-cell-related. The known ECL-cell-related genes are those encoding histidine decarboxylase, chromogranin A and B, vesicular monoamine transporter 2, synaptophysin, and the cholecystokinin-B receptor. In addition, the fingerprint included five genes, which might be involved in the process of secretion and three ESTs with unknown function. Interestingly, parathyroid hormone-like hormone (Pthlh) was identified as a candidate ECL-cell peptide hormone.
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Affiliation(s)
- Niklas Andersson
- Center for Bone Research at the Sahlgrenska Academy (CBS), Department of Internal Medicine, Division of Endocrinology, Göteborg University, Göteborg, Sweden.
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Shiga K, Hara H, Takahashi T, Aoyama Y, Furuta H, Maeda H. Ingestion of water-soluble soybean fiber improves gastrectomy-induced calcium malabsorption and osteopenia in rats. Nutrition 2002; 18:636-42. [PMID: 12093445 DOI: 10.1016/s0899-9007(02)00743-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Total gastrectomy produces calcium malabsorption and osteopenia. We examined the effects of feeding water-soluble soybean fiber (WSSF), a highly fermentable dietary fiber with low viscosity, on calcium absorption and bone characteristics in totally gastrectomized rats. METHODS Male Sprague-Dawley rats were assigned to two groups: sham operation and gastrectomy. After the postoperative recovery period, rats of each group were fed diets with or without WSSF (50 g/kg diet) for 4 wk. RESULTS Net calcium absorption and femoral dry weight and calcium content and maximum breaking force were lower in the gastrectomy groups than in the sham groups. In the gastrectomy groups, calcium absorption and these femoral parameters were higher in rats fed the WSSF diet than in rats fed the WSSF-free diet. Feeding WSSF increased the concentrations of short-chain fatty acids and soluble calcium and decreased the pH in cecal contents. Net calcium absorption in gastrectomized rats correlated positively with the concentration of total short-chain fatty acids (the sum of acetic, propionic, and butyric acids) in cecal contents (r = 0.545, P < 0.05) and negatively with cecal pH (r = -0.628, P < 0.05). CONCLUSIONS These findings indicate that ingestion of WSSF partly prevents the diminished calcium absorption after total gastrectomy in rats, resulting in the improvement of postgastrectomy osteopenia. The increase of calcium absorption may be associated with cecal fermentation of WSSF.
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Affiliation(s)
- Kazuki Shiga
- Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita-9, Nishi-9, Kita-ku, Sapporo 060-8589, Japan
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Larsson B, Norlén P, Lindström E, Zhao D, Håkanson R, Linde A. Effects of ECL cell extracts and granule/vesicle-enriched fractions from rat oxyntic mucosa on cAMP and IP(3) in rat osteoblast-like cells. REGULATORY PEPTIDES 2002; 106:13-8. [PMID: 12047905 DOI: 10.1016/s0167-0115(02)00024-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The existence of an osteotropic hormone (referred to as gastrocalcin) in the ECL cells of the gastric mucosa has been suggested. Both gastrin and an extract of the oxyntic mucosa lower blood Ca(2+) and stimulate Ca(2+) uptake into bone. The ECL cells are known to operate under gastrin control and, conceivably, gastrin lowers blood Ca(2+) indirectly by releasing the hypothetical ECL cell hormone. We have shown earlier that extracts of isolated ECL cells or of the granule/vesicle fraction of the oxyntic mucosa evoke a typical Ca(2+)-mediated second messenger response in osteoblastic cells. In the present study, we characterize this response further. An increase in intracellular inositol 1,4,5-trisphosphate (IP(3)) concentration was observed after treatment of UMR-106.01 osteoblast-like cells with extracts of ECL cells or granule/vesicle-enriched fractions from oxyntic mucosa. Intracellular cyclic adenosine monophosphate (cAMP) concentrations were not affected. Inhibition of phospholipase C (PLC) by U-73122 abolished the increase in [Ca(2+)](i). Preincubation of UMR-106.01 cells with pertussis toxin, which blocks many G-proteins, did not prevent the increases in IP(3) and [Ca(2+)](i). It was also found that the novel peptide hormone ghrelin, produced in the A-like cells of the oxyntic mucosa, did not evoke any Ca(2+) signal in osteoblastic cells. The results indicate that the extracts mediate their effects through a pertussis toxin-insensitive mechanism, and that binding to a receptor leads to activation of PLC and production of IP(3) resulting in increased [Ca(2+)](i). The putative osteotropic hormone is distinct from ghrelin.
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Affiliation(s)
- Birgitta Larsson
- Department of Oral Biochemistry, Göteborg University, Box 450, SE-405 30 Göteborg, Sweden
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31
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Morohashi T, Hirama Y, Takahara S, Sano T, Saitoh S, Ohta A, Sasa R, Yamada S. Defects in mandibular bone area, enamel iron content and dentine formation following gastrectomy in rats. Arch Oral Biol 2002; 47:499-504. [PMID: 12102767 DOI: 10.1016/s0003-9969(02)00016-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: 11/20/2022]
Abstract
Fourteen 5-week-old male Sprague-Dawley rats were equally divided into two groups, sham-operated and gastrectomized. Tetracycline and calcein were given to label dentine. Four weeks after surgery, blood was collected for measurement of serum iron, calcium and parathyroid hormone (PTH) and the mandibles and maxillae were then removed. Sagittal sections of the maxilla or cross-sections of the mandible were prepared and examined. Backscattered electron images of the maxilla were taken and the iron content at the neck of incisors was measured by energy-dispersive X-ray. The dentine apposition rate in maxillary incisors was measured by fluorescence microscopy. Serum iron was significantly decreased, while PTH was significantly elevated without any change in the serum calcium in gastrectomized rats. Gastrectomy caused a gross loss of iron content in superficial enamel. The dentine apposition rate was significantly reduced by 30%. Both cortical and cancellous bone in the mandibula were significantly reduced. However, the total bone area in gastrectomized rats was similar to that in sham-operated rats. These results suggest that bone resorption was enhanced and dentine formation was reduced after gastrectomy.
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Affiliation(s)
- Tomio Morohashi
- Department of Pharmacology, School of Dentistry, Showa University, Hatanodai 1-5-8, Shinagawa-ku, Tokyo 142-8555, Japan.
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Surve VV, Andersson N, Lehto-Axtelius D, Håkanson R. Comparison of osteopenia after gastrectomy, ovariectomy and prednisolone treatment in the young female rat. ACTA ORTHOPAEDICA SCANDINAVICA 2001; 72:525-32. [PMID: 11728082 DOI: 10.1080/000164701753532880] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Rat models of osteopenia include ovariectomy and long-term glucocorticoid treatment. Although ovariectomy produces significant trabecular bone loss after 2 weeks, long-term glucocorticoid treatment has been reported to cause osteopenia in some studies but not in others. In the present 8-week-study, we compared the osteopenia associated with gastrectomy (GX) to that induced by ovariectomy (OVX) or prednisolone (PRE) treatment. Female Sprague-Dawley rats (10 weeks old) were subjected to GX, OVX, PRE treatment or SHAM operation. At the end of the study, calvariae, femurs and fifth lumbar vertebrae (L5) were collected and subjected to bone density measurement (femur and L5), transillumination (calvaria) and histomorphometry (calvaria and femur). Bone density was reduced in L5 and the distal femur in the OVX and GX groups, but not in the PRE group. Transillumination of the calvaria showed marked bone loss in the GX rats, but not in the other groups. Morphometric analysis of the femur revealed reduced trabecular bone volume, trabecular thickness, trabecular number and osteoclast number, but increased osteoclast surface (expressed as per cent of the trabecular bone surface covered by osteoclasts) in the GX and OVX rats. The PRE rats seemed unaffected. Cortical thickness was reduced in the GX rats, but not in the other groups. The findings indicate that GX induces osteopenia in, e.g., femur and vertebra of a magnitude similar to or greater than that induced by OVX, while at the same time inducing osteopenia in the calvaria. Although osteoclast activation seems to contribute, the precise mechanism underlying the GX-evoked osteopenia remains obscure.
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Affiliation(s)
- V V Surve
- Department of Pharmacology, Institute of Physiological Sciences, University of Lund, Sweden
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Cui GL, Syversen U, Zhao CM, Chen D, Waldum HL. Long-term omeprazole treatment suppresses body weight gain and bone mineralization in young male rats. Scand J Gastroenterol 2001; 36:1011-5. [PMID: 11589371 DOI: 10.1080/003655201750422585] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND The stomach is rich in endocrine cells, including those producing ghrelin, which is thought to play a role in the control of body growth. Omeprazole treatment is associated with hypergastrinaemia, resulting in growth of the oxyntic mucosa in general and the enterochromaffin-like (ECL) cells in particular. In the present study, we examined the effects of long-term omeprazole treatment on young male rats with respect to body growth and stomach. METHODS Male rats (24 days old) were treated with omeprazole (400 micromol/kg/day) or vehicle for 77 days. The body weight was recorded twice per week. At sacrifice, dual-energy X-ray absorptiometry (DXA) was used to assess total bone area, bone mineral content (BMC), bone mineral density (BMD) and body composition (fat and lean body mass). The lengths of the spine and the femur were recorded. The plasma concentrations of gastrin and histamine were determined by radioimmunoassays. The endocrine cells of the stomach were examined by immunocytochemistry. RESULTS The body weight gain was suppressed by omeprazole treatment. The bone area, BMC and BMD were reduced, while the lengths of the spine and the femur and the body composition were unchanged. Omeprazole-induced hypergastrinaemia was associated with enlargement of the oxyntic area and with hyperplasia of ECL cells but not of A-like cells and D cells. In contrast, the enterchromaffin (EC) cell density in the antrum was reduced. CONCLUSIONS Omeprazole treatment of young male rats reduces body weight and bone mass gain. The densities of ECL cells in the oxyntic mucosa was increased and of the EC cells in the antral mucosa reduced.
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Affiliation(s)
- G L Cui
- Dept. of Physiology and Biomedical Engineering, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim
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Dornonville de la Cour C, Björkqvist M, Sandvik AK, Bakke I, Zhao CM, Chen D, Håkanson R. A-like cells in the rat stomach contain ghrelin and do not operate under gastrin control. REGULATORY PEPTIDES 2001; 99:141-50. [PMID: 11384775 DOI: 10.1016/s0167-0115(01)00243-9] [Citation(s) in RCA: 252] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ghrelin is a 28 a.a. gastric peptide, recently identified as a natural ligand of the growth hormone secretagogue receptor (orphan receptor distinct from the receptor for growth hormone releasing hormone). In the present study, radioimmunoassay demonstrated ghrelin-like material in the rat oxyntic mucosa with moderate amounts also in antrum and duodenum. Small amounts were found in the distal intestines and pancreas. Northern blot analysis revealed abundant ghrelin mRNA in the oxyntic mucosa. Immunocytochemistry demonstrated ghrelin-immunoreactivity in endocrine-like cells in the oxyntic mucosa. Such cells occurred in low numbers also in the antrum and duodenum. The rat oxyntic mucosa is rich in endocrine (chromogranin A/pancreastatin-immunoreactive) cells, such as the histamine-rich ECL cells (65-75% of the endocrine cells), the A-like cells (20-25%) and the D cells (somatostatin cells) (10%). The ghrelin-immunoreactive (IR) cells contained pancreastatin but differed from ECL cells and D cells by being devoid of histamine-forming enzyme (ECL cell constituent) and somatostatin (D cell constituent). Hence, ghrelin seems to occur in the A-like cells. The ghrelin-IR cells in the antrum were distinct from the gastrin cells, the serotonin-containing enterochromaffin cells and the D cells. Conceivably, ghrelin cells in the antrum and distally in the intestines also belong to the A-like cell population. The concentration of ghrelin in the circulation was lowered by about 80% following the surgical removal of the acid-producing part of the stomach in line with the view that the oxyntic mucosa is the major source of ghrelin. The serum ghrelin concentration was higher in fasted rats than in fed rats; it was reduced upon re-feeding and seemed unaffected by 1-week treatment with the proton pump inhibitor omeprazole, resulting in elevated serum gastrin concentration. Infusion of gastrin-17 for 2 days failed to raise the serum ghrelin concentration. Omeprazole treatment for 10 weeks raised the level of HDC mRNA but not that of ghrelin mRNA or somatostatin mRNA in the oxyntic mucosa. Hence, unlike the ECL cells, ghrelin-containing A-like cells do not seem to operate under gastrin control.
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Affiliation(s)
- C Dornonville de la Cour
- Department of Pharmacology, Institute of Physiological Sciences, Lund University, Solvegatan 10, S-223 62, Lund, Sweden
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Larsson B, Gritli-Linde A, Norlén P, Lindström E, Håkanson R, Linde A. Extracts of ECL-cell granules/vesicles and of isolated ECL cells from rat oxyntic mucosa evoke a Ca2+ second messenger response in osteoblastic cells. REGULATORY PEPTIDES 2001; 97:153-61. [PMID: 11164951 DOI: 10.1016/s0167-0115(00)00210-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Surgical removal of the acid-producing part of the stomach (oxyntic mucosa) reduces bone mass through mechanisms not yet fully understood. The existence of an osteotropic hormone produced by the so-called ECL cells has been suggested. These cells, which are numerous in the oxyntic mucosa, operate under the control of circulating gastrin. Both gastrin and an extract of the oxyntic mucosa decrease blood calcium and stimulate Ca2+ uptake into bone. Conceivably, gastrin lowers blood calcium indirectly by releasing a hypothetical hormone from the ECL cells. The present study investigated, by means of fura-2 fluorometry, the effect of extracts of preparations enriched in ECL cell granules/vesicles from rat oxyntic mucosa on mobilization of intracellular Ca2+ in three osteoblast-like cell lines, UMR-106.01, MC3T3-E1 and Saos-2, and of extracts of isolated ECL cells in UMR-106.01 cells. The extracts were found to induce a dose-related rapid increase in intracellular Ca2+ concentrations in the osteoblast-like cells. The response was not due to histamine or pancreastatin, known ECL cell constituents, and could be abolished by pre-digesting the extracts with exo-aminopeptidase. The results show that the increase in [Ca2+](i) reflects a mobilization of Ca2+ from the endoplasmic reticulum. The observation of an increase in [Ca2+](i) also in murine embryonic fibroblasts show that the response is not limited to osteoblastic cells. The finding that the extracts evoked a typical Ca2+ -mediated second messenger response in osteoblastic cells provides evidence for the existence of a novel osteotropic peptide hormone (gastrocalcin), produced in the ECL cells, and supports the view that gastrectomy-induced osteopathy may reflect a lack of this hormone.
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Affiliation(s)
- B Larsson
- Department of Oral Biochemistry, Göteborg University Box 450, SE-405 30 Göteborg, Sweden
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36
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Gepp H, Koch M, Schwille PO, Erben RG, Rümenapf G, Schmiedl A, Fries W. Vagus-sparing gastric fundectomy in the rat: development of osteopenia, relationship to urinary phosphate and net acid excretion, serum gastrin and vitamin D. RESEARCH IN EXPERIMENTAL MEDICINE. ZEITSCHRIFT FUR DIE GESAMTE EXPERIMENTELLE MEDIZIN EINSCHLIESSLICH EXPERIMENTELLER CHIRURGIE 2000; 200:1-16. [PMID: 11197917 DOI: 10.1007/s004330000048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In man and experimental animals, partial and total gastrectomy and gastric vagotomies disturb extracellular mineral homeostasis, osteopenia being among the late outcomes. The sequence of events is complex and insufficiently understood. We report on the long-term effects of gastric fundectomy (FX; FX-1, n=11; sham-operated controls, n=14) sparing gastric vagal fibers at the lesser curvature in the rat, a procedure eliminating gastric acid production but preserving gastric reservoir function. After FX-1 there was a marked increase of gastrinemia [FX-1: 590 (SE 95); controls: 82 (5) pg-equiv/ml; P<0.001], serum 1,25-dihydroxyvitamin D [FX-1: 188 (17); controls: 86 (6) pg/ml; P<0.001], phosphaturia [FX-1: 32 (2); controls 23 (2) micromol/h; P<0.001] due to increased fractional phosphate clearance, elevated urinary net acid [FX-1: 21 (2); controls: 16 (1) micromol/h; P=0.03], and low urinary pH. The urinary excretion of hydroxyproline was increased [FX-1: 137 (15); controls: 99 (8) micromol/h; P=0.01], and crosslinks were also high. These changes were associated with a significant decrease of bone ash calcium, magnesium, and phosphorus. Bone histomorphometry revealed signs of high bone turnover. No signs of hyperparathyroidism were detectable. Acute stimulation of serum gastrin by gastric acid abolishing omeprazole failed to provoke extra-osseous changes, as seen in the long-term after fundectomy. It was concluded that the described type of fundectomy disturbs gastrinemia, acid-base and phosphorus metabolism, thereby initiating osteopenia. This animal model may be suitable for research into post-gastrectomy bone disease.
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Affiliation(s)
- H Gepp
- Division of Experimental Surgery and Endocrine Research Laboratory, Friedrich-Alexander University, Erlangen, Germany
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Stenström M, Olander B, Lehto-Axtelius D, Madsen JE, Nordsletten L, Carlsson GA. Bone mineral density and bone structure parameters as predictors of bone strength: an analysis using computerized microtomography and gastrectomy-induced osteopenia in the rat. J Biomech 2000; 33:289-97. [PMID: 10673112 DOI: 10.1016/s0021-9290(99)00181-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In this study the relationships of bone mineral density (BMD) and bone structure parameters calculated from 2D microtomography images to bone strength were investigated. Femurs from 21 male Sprague Dawley rats were subjected to dual-energy X-ray absorptiometry, computerized microtomography (CmicroT) and either three-point cantilever bending (femoral shaft) or two-point bending compression (femoral neck). Gastrectomy was performed on 12 animals and 9 were sham operated. From the tomograms bone structure analysis was performed using a software routine based on grey level run-length method. Correlations of BMD and bone structure parameters to mechanical parameters were investigated as were differences between the gastrectomized and the control samples. The reductions of BMD between the groups were 21 and 27% in the femoral neck and shaft, respectively. For the shaft, the correlations of BMD to all mechanical parameters were significant and BMD was a consistent predictor of bone strength for cortical bone. However, in the femoral neck where cancellous bone predominates, BMD was weakly correlated only to deflection. A significant correlation between trabecular thickness and neck bone strength was found. Hence, compared to trabecular thickness, BMD was of limited value in predicting bone strength in the femoral neck.
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Affiliation(s)
- M Stenström
- Department of Radiation Physics, IMV, Faculty of Health Sciences, Linköping University, Sweden
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Rümenapf G, Schwille PO. Postgastrectomy osteopenia in minipigs. Ann Surg 1999; 229:592-4. [PMID: 10203095 PMCID: PMC1191749 DOI: 10.1097/00000658-199904000-00022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Chen D, Zhao CM, Lindström E, Håkanson R. Rat stomach ECL cells up-date of biology and physiology. GENERAL PHARMACOLOGY 1999; 32:413-22. [PMID: 10323481 DOI: 10.1016/s0306-3623(98)00221-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The ECL cell is the predominant endocrine cell type in the oxyntic mucosa, displaying typical ultrastructure with numerous cytoplasmic vesicles and electron-dense granules. ECL cells have many features in common with neurons and other peptide hormone-producing endocrine cells, including the ability to produce, store, and secrete chromogranin-A and chromogranin A-derived peptides. In addition, they produce and store histamine and respond with activation and growth to a gastrin challenge. ECL cells are stimulated to secrete histamine as well as other products by gastrin and PACAP and are inhibited by somatostatin, galanin, and prostaglandins. The cytoplasmic vesicles are thought to contain histamine and other secretory products. Mature secretory vesicles occur in the docking zone of the ECL cells, where they constitute the releasable pool of secretory products. Gastrin stimulation will induce exocytosis and degranulation. Histamine released from ECL cells plays a key role in the regulation of parietal cell activity (the gastrin-ECL cell-parietal cell axis). In response to long-term gastrin stimulation, vacuoles and lipofuscin bodies develop in the ECL cells, forming part of a crinophagic pathway by which the ECL cell strives to eliminate superfluous secretory products.
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Affiliation(s)
- D Chen
- Department of Pharmacology, University of Lund, Sweden
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Gagnemo-Persson R, Persson P, Bryngelsson T, Greén B, Håkanson R. Rat stomach ECL-cell histidine decarboxylase activity is suppressed by ergocalciferol but unaffected by parathyroid hormone and calcitonin. REGULATORY PEPTIDES 1999; 79:131-9. [PMID: 10100926 DOI: 10.1016/s0167-0115(98)00158-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ECL cells are peptide hormone-producing cells, rich in histamine and chromogranin A (CGA)-derived peptides, that operate under the control of gastrin. Gastrin and the ECL cells form a functional unit, the gastrin-ECL-cell axis. The aims of the present study were to examine (1) if calcitonin (CT), parathyroid hormone (PTH) and vitamin D affect the gastrin-ECL-cell axis (by measuring the activity of the histamine-forming enzyme, histidine decarboxylase (HDC), and the expression of HDC mRNA and CGA mRNA in the ECL cells), and (2) if activation of the gastrin-ECL-cell axis affects the parathyroid glands (by measuring plasma PTH and mRNA expression). We also examined the possibility that the oxyntic mucosa harbours vitamin D receptors. Fasted rats received intravenous infusion of PTH and CT with or without gastrin. PTH raised the blood Ca2+ concentration, whereas CT infusion lowered it. Plasma PTH rose in response to CT, while serum gastrin remained unaffected. ECL-cell HDC was activated by gastrin but not by CT and PTH. Five daily subcutaneous injections of large amounts of ergocalciferol raised the blood Ca2+ concentration, while reducing the oxyntic mucosal HDC activity and the expression of HDC and CGA mRNA. The serum gastrin concentration was not affected. The findings are in line with the idea that the gastrin-ECL-cell axis can be suppressed by vitamin D or by vitamin D-dependent mechanisms. Western blot analysis revealed the presence of vitamin D receptor immunoreactivity and reverse transcription PCR detected vitamin D receptor gene expression in the rat oxyntic mucosa. Hypergastrinemia was induced by daily peroral treatment with the H+/K+-ATPase inhibitor, omeprazole, for 2 weeks or by continuous subcutaneous infusion of gastrin for 7 days. Elevated serum gastrin concentration was associated with increased HDC activity and increased HDC and CGA mRNA expression in the oxyntic mucosa. There was no elevation of plasma PTH or PTH mRNA expression in the parathyroid gland.
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Hara H, Suzuki T, Kasai T, Aoyama Y, Ohta A. Ingestion of guar gum hydrolysate, a soluble fiber, increases calcium absorption in totally gastrectomized rats. J Nutr 1999; 129:39-45. [PMID: 9915873 DOI: 10.1093/jn/129.1.39] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Gastrectomy induces osteopenia. We examined the effects of feeding a diet containing soluble dietary fiber, guar gum hydrolysate (GGH, 50 g/kg diet), on intestinal calcium absorption and bone mineralization in totally gastrectomized (Roux-en-Y esophagojejunostomy) rats by comparing them with those in two control groups (laparotomized and bypassed rats). In the bypassed rats, chyme bypassed the duodenum and upper jejunum without gastrectomy. In a second separate experiment, we compared calcium absorption and bone mineralization in the gastrectomized rats fed diets containing soluble and insoluble calcium salts and in bypassed rats fed insoluble calcium. In Experiment 1, apparent absorption of calcium supplied as a water-insoluble salt was more than 50% lower in gastrectomized rats than in the intact (laparotomized) or bypassed rats 3 wk after the start of feeding the test diets (P < 0.05). Calcium absorption was higher (P < 0.05) in gastrectomized rats fed the GGH diet than in those rats fed the GGH-free diet. In Experiment 2, absorption of soluble calcium in the gastrectomized rats did not differ from the absorption of calcium from calcium carbonate by bypassed rats. The soluble calcium pool in the cecal contents was significantly lower in gastrectomized rats (Experiment 1) than in intact or bypassed control rats, and was higher (P < 0.05) in the GGH-fed gastrectomized rats than in those fed the GGH-free diet. However, calcium absorption correlated most closely (r = 0.787, P < 0.01) with cecal propionic acid concentration. The femur calcium content was significantly lower in gastrectomized rats fed insoluble calcium than in bypassed rats fed the same diet, but was partially restored in the rats fed soluble calcium (Experiment 2). Bone calcium was not increased by feeding GGH in gastrectomized rats (Experiment 1). We conclude that the severely diminished calcium absorption following total gastrectomy is totally due to a decrease in calcium solubilization, and feeding GGH partially restores calcium absorption. The decrease in bone calcium that occurs as a result of gastrectomy is mainly due to diminished intestinal calcium absorption.
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Affiliation(s)
- H Hara
- Department of Bioscience and Chemistry, Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
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Lehto-Axtelius D, Stenström M, Johnell O. Osteopenia after gastrectomy, fundectomy or antrectomy: an experimental study in the rat. REGULATORY PEPTIDES 1998; 78:41-50. [PMID: 9879745 DOI: 10.1016/s0167-0115(98)00101-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Gastrectomy induces osteopenia. In this study, we tested if resection of defined parts of the stomach could reproduce the gastrectomy-evoked osteopenia. METHODS Rats were subjected to gastrectomy (surgical removal of the glandular part of the stomach), fundectomy (extirpation of the acid-producing part, fundus) or antrectomy (extirpation of the gastrin-producing part, antrum). Calvariae, tibiae and femurs were examined at various times after the operations. The calvariae were subjected to transillumination. Calvariae and tibiae were sectioned and analysed by histomorphometry, tibia sections by the aid of a Merz grid and calvaria sections using computer-assisted image analysis. The intact femurs were subjected to computerized microtomography. RESULTS Gastrectomy (hypogastrinemia) and fundectomy (hypergastrinemia) resulted in osteopenia, while antrectomy (hypogastrinemia) had less effect on bone. Gastrectomy/fundectomy were associated with loss of trabecules in the tibia and with reduced bone volume in both tibia and calvaria. In contrast, there was only little reduction of cortical bone in the femur. CONCLUSION Gastrectomy-evoked osteopenia can be reproduced by selective resection of the acid-producing part of the rat stomach (i.e. fundectomy). Antrectomy was less effective. In the long bones, the osteopenia was manifested primarily in trabecular bone and less in cortical bone. The calvaria displayed marked osteopenia. Although the findings indicate that the stomach, notably the acid-producing (oxyntic) mucosa, is important for bone metabolism, the precise mechanisms behind the gastrectomy/fundectomy-evoked osteopenia remain unidentified. Clearly, lack of gastrin is not responsible. The oxyntic mucosa is rich in peptide hormone-producing cells (the so-called ECL cells), with unidentified physiological significance. The ECL cells, which operate under the control of gastrin, have been put forward as a possible source of an osteotropic hormone.
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Affiliation(s)
- D Lehto-Axtelius
- Department of Radiology, Centre for Oral Health Sciences Malmö, Sweden
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Ohta A, Motohashi Y, Sakai K, Hirayama M, Adachi T, Sakuma K. Dietary fructooligosaccharides increase calcium absorption and levels of mucosal calbindin-D9k in the large intestine of gastrectomized rats. Scand J Gastroenterol 1998; 33:1062-8. [PMID: 9829361 DOI: 10.1080/003655298750026769] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND In gastrectomized rats intestinal calcium absorption and bone calcium levels markedly decrease and the levels recover as a result of feeding fructooligosaccharides (FOS). In the present study we examined the effects of gastrectomy and dietary FOS on intestinal calbindin-D9k (CaBP) levels. METHODS One group of rats was subjected to a sham operation and fed a control diet. Two other groups of rats were gastrectomized, and those in one group were fed the control diet, whereas those in the other group were fed a diet containing 10% FOS. Intestinal calcium, magnesium, and phosphorus absorption levels and intestinal CaBP levels were measured. RESULTS Gastrectomy increased CaBP levels in the distal small intestine, cecum, and colorectum but markedly decreased calcium absorption. Dietary FOS increased CaBP levels in the cecum and colorectum in the case of gastrectomized rats and improved calcium absorption. CONCLUSIONS The results suggest that dietary FOS not only improve intestinal calcium absorption but also serve to maintain local calcium homeostasis in the intestine by increasing mucosal CaBP levels in the large intestine of gastrectomized rats.
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Affiliation(s)
- A Ohta
- Nutritional Science Center, Bioscience Laboratories, Meiji Seika Kaisha, Ltd., Sakado, Saitama, Japan
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Survé VV, Håkanson R. Evidence that peroral calcium does not activate the gastrin-ECL-cell axis in the rat. REGULATORY PEPTIDES 1998; 73:177-82. [PMID: 9556080 DOI: 10.1016/s0167-0115(98)00002-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The ECL cells are histamine- and pancreastatin-secreting endocrine cells in the oxyntic mucosa, thought to release a blood Ca2+-lowering peptide hormone upon stimulation by gastrin. Previously, we have shown that the ECL cells do not respond to perturbations in blood Ca2+. In the present study, we examine if Ca2+ in the gastric lumen will affect the activity of the gastrin-ECL-cell axis. Freely fed or food deprived (48 h) rats were given an oral load of CaCl2 (or NaCl), and the blood Ca2+ concentration was monitored. The serum gastrin concentration at sacrifice, 3 h after ingestion of CaCl2, was measured together with two parameters of ECL cell activity: the oxyntic mucosal histidine decarboxylase (HDC) activity and the serum pancreastatin concentration. The circulating concentrations of calcitonin and parathyroid hormone (PTH) were also measured. Oral CaCl2 raised the blood Ca2+ in a dose-dependent manner. The two highest doses (which caused damage to the oxyntic mucosa) raised the serum gastrin concentration and the HDC activity in both fed and fasted rats; the serum pancreastatin concentration remained unaffected. Oral CaCl2 raised the serum calcitonin concentration and lowered the serum PTH concentration. The effects of high doses of oral CaCl2 on the serum gastrin concentration and on the oxyntic mucosal HDC activity could be reproduced by a high dose of NaCl. Thus the effects are probably not due to Ca2+ per se. We conclude that the gastrin-ECL-cell axis in the rat does not respond to peroral Ca2+. Since the ECL cells do not respond to either circulating or peroral Ca2+ they are unlikely to secrete a calciotropic hormone.
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Affiliation(s)
- V V Survé
- Department of Pharmacology, University of Lund, Sweden
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Ohta A, Ohtsuki M, Hosono A, Adachi T, Hara H, Sakata T. Dietary fructooligosaccharides prevent osteopenia after gastrectomy in rats. J Nutr 1998; 128:106-10. [PMID: 9430610 DOI: 10.1093/jn/128.1.106] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Postgastrectomy osteopenia is observed generally in humans. Fructooligosaccharides increase the absorption of calcium from the large intestine of healthy rats. Thus, we have examined whether they stimulate calcium absorption and prevent osteopenia in rats following total gastrectomy. Rats were subjected to either a sham surgical operation or Billoth II gastrectomy. Seven rats from each surgical treatment group were fed a control diet, and another seven rats of each treatment group were fed a diet containing fructooligosaccharides (75 g/kg diet) for 4 wk. For 5 d each week, feces were collected, and the calcium and phosphorus contents were measured for calculation of the absorption of these minerals. At the end of the experiment, the rats were killed and bones were collected. The net calcium absorption, calcium content and bone mineral density of the femur and tibia in gastrectomized rats fed the control diet were significantly less than those in sham-operated rats fed control diet. The net calcium absorption in rats fed the fructooligosaccharides diet was greater than that in rats fed control diet. Moreover, dietary fructooligosaccharides prevented the decrease in the calcium content and bone mineral density in gastrectomized rats. Dietary fructooligosaccharides enhanced calcium absorption and prevented the changes indicative of postgastrectomy osteopenia such as decreases in bone calcium content and bone mineral density in gastrectomized rats.
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Affiliation(s)
- A Ohta
- Nutritional Science Center, Bioscience Laboratories, Meiji Seika Kaisha, Ltd., Saitama 350-02, Japan
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Klinge B, Lehto-Axtelius D, Akerman M, Håkanson R. Structure of calvaria after gastrectomy. An experimental study in the rat. Scand J Gastroenterol 1995; 30:952-7. [PMID: 8545614 DOI: 10.3109/00365529509096337] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Gastrectomy induces bone loss, suggesting that the stomach is important for calcium homeostasis. In this study we examined the effects of gastrectomy, with or without CaCl2 supplementation, on the structure of the calvaria of the rat. METHODS The calvaria were dissected out and transilluminated, and the calvaria thickness was measured before (micrometer) and after fixation and sectioning (microscopy). Sections of the skull were analysed planimetrically for bone tissue area, using computer-assisted image analysis. RESULTS The time course of the gastrectomy-produced bone loss was studied. After 4 weeks the remaining bone represented about 70% of that in control rats, and after 8 weeks the value was 50%. The thickness of the calvaria was lower in gastrectomized rats than in sham-operated controls. Bone marrow and samples from liver and spleen were examined; no differences were found between experimental and control groups. Daily ingestion of 100 mg CaCl2.2H2O did not prevent the bone loss. CONCLUSIONS It is unlikely that the gastrectomy-produced bone loss reflects calcium deficiency. The results rather support the view that the stomach is important for calcium homeostasis through another mechanism, perhaps involving a hypothetical gastric hormone.
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Affiliation(s)
- B Klinge
- Dept. of Periodontology, University of Lund, Malmö, Sweden
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Stenström M, Olander B, Carlsson CA, Carlsson GA, Håkanson R. Methodologic aspects of computed microtomography to monitor the development of osteoporosis in gastrectomized rats. Acad Radiol 1995; 2:785-91. [PMID: 9419640 DOI: 10.1016/s1076-6332(05)80487-8] [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: 02/05/2023]
Abstract
RATIONALE AND OBJECTIVES We investigated the methodologic development of computed microtomography (CMT) for monitoring the development of osteoporosis in male Sprague-Dawley rats. METHODS Eight rats were gastrectomized and eight rats were sham operated. Femurs, tibias, and tails were prepared, and CMT scans with spatial resolutions of 5-500 microns were made. Bone diameters, bone areas, and moments of inertia were determined from the CMT scans. Optimal slice position and the need for spatial resolution and energy optimization for future in vivo applications were investigated. RESULTS Gastrectomy caused dramatic changes in the bone architecture of the tibia and the femur. The main features were vacuolization of the bone and reduced amounts of compact bone. Although the outer diameters of tubular bones (femur and tibia) were largely unaffected, their inner diameters were greatly increased following gastrectomy. Relative bone area and moment of inertia were greatly reduced. The optimal photon energy was 12 keV. CONCLUSION It is possible to monitor gastrectomy-evoked changes in bone morphology at various sites in rats using CMT scanning. The changes are suggestive of osteoporosis. By optimizing the energy spectrum and spatial resolution, as well as choosing the proper slice position, it should be possible to keep absorbed doses low enough to avoid acute radiation injury in repeated in vivo measurements.
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Affiliation(s)
- M Stenström
- Radiation Physics Department, Faculty of Health Sciences, Linköping University, Sweden
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Rooryck V, Klinge B. Computer-assisted image processing for quantitative measurements of fractional bone area. A methodologic study. Acta Odontol Scand 1995; 53:115-22. [PMID: 7610775 DOI: 10.3109/00016359509005957] [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]
Abstract
The purpose of this study was to evaluate a method for computer-assisted image processing to assess quantitatively fractional bone volume in sections of bone biopsies (part I). A second purpose was to apply this method in an experimental study to determine bone loss by measuring fractional bone area in sections of calvarial bone of gastrectomized rats and to compare this with a control group. Stained paraffin sections of skull bone of young rabbits (part I) and rats (part II) were examined. The histologic sections were placed on a microscope. A video camera was connected to the microscope, and the image transferred to a display monitor connected to a PC with dedicated software, performing the measurements. In the first part of the study tests of the reproducibility of the method were performed. The influence of factors such as external illumination and light intensity in the microscope was evaluated by measuring the same area several times at different times (= different illumination) and at different microscope light intensity levels. The automatic method was compared with a manual method, using a Merz grid but automatically calculated. The difference between the means of the manual and automatic measurements was determined with the paired t test. In the second part of the study the unpaired t test was used to determine the differences between the control group and experimental group, both for the manually and the automatically measured values.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- V Rooryck
- Department of Periodontology, Lund University, Malmö, Sweden
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