1
|
Hakimi S, Dutta P, Layton AT. Renal calcium and magnesium handling during pregnancy: modeling and analysis. Am J Physiol Renal Physiol 2024; 327:F77-F90. [PMID: 38721663 DOI: 10.1152/ajprenal.00001.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 04/15/2024] [Accepted: 05/05/2024] [Indexed: 06/21/2024] Open
Abstract
Pregnancy is associated with elevated demand of most nutrients, with many trace elements and minerals critical for the development of fetus. In particular, calcium (Ca2+) and magnesium (Mg2+) are essential for cellular function, and their deficiency can lead to impaired fetal growth. A key contributor to the homeostasis of these ions is the kidney, which in a pregnant rat undergoes major changes in morphology, hemodynamics, and molecular structure. The goal of this study is to unravel the functional implications of these pregnancy-induced changes in renal handling of Ca2+ and Mg2+, two cations that are essential in a healthy pregnancy. To achieve that goal, we developed computational models of electrolyte and water transport along the nephrons of a rat in mid and late pregnancy. Model simulations reveal a substantial increase in the reabsorption of Mg2+ along the proximal tubules and thick ascending limbs. In contrast, the reabsorption of Ca2+ is increased in the proximal tubules but decreased in the thick ascending limbs, due to the lower transepithelial concentration gradient of Ca2+ along the latter. Despite the enhanced transport capacity, the marked increase in glomerular filtration rate results in elevated urinary excretions of Ca2+ and Mg2+ in pregnancy. Furthermore, we conducted simulations of hypocalcemia and hypomagnesemia. We found that hypocalcemia lowers Ca2+ excretion substantially more than Mg2+ excretion, with this effect being more pronounced in virgin rats than in pregnant ones. Conversely, hypomagnesemia reduces the excretion of Mg2+ and Ca2+ to more similar degrees. These differences can be explained by the greater sensitivity of the calcium-sensing receptor (CaSR) to Ca2+ compared with Mg2+.NEW & NOTEWORTHY A growing fetus' demands of minerals, notably calcium and magnesium, necessitate adaptations in pregnancy. In particular, the kidney undergoes major changes in morphology, hemodynamics, and molecular structure. This computational modeling study provides insights into how these pregnancy-induced renal adaptation impact calcium and magnesium transport along different nephron segments. Model simulations indicate that, despite the enhanced transport capacity, the marked increase in glomerular filtration rate results in elevated urinary excretions of calcium and magnesium in pregnancy.
Collapse
Affiliation(s)
- Shervin Hakimi
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Pritha Dutta
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Anita T Layton
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
- Department of Biology, Cheriton School of Computer Science, and School of Pharmacology, University of Waterloo, Waterloo, Ontario, Canada
| |
Collapse
|
2
|
Gonuguntla V, Talwar V, Krishna B, Srinivasan G. Correlation of Serum Magnesium Levels with Clinical Outcome: A Prospective Observational Study in Critically Ill Patients Admitted to a Tertiary Care ICU in India. Indian J Crit Care Med 2023; 27:342-347. [PMID: 37214118 PMCID: PMC10196642 DOI: 10.5005/jp-journals-10071-24451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 04/04/2023] [Indexed: 05/24/2023] Open
Abstract
Background We studied the incidence of magnesium (Mg) disturbances in patients admitted to a multidisciplinary intensive care unit (ICU) and correlated serum magnesium levels with clinical outcomes. Materials and methods The study was conducted on 280 critically ill patients aged above 18 years and admitted to the ICU. Serum magnesium levels at admission were correlated with mortality, need for and duration of mechanical ventilation, duration of ICU stay, presence of comorbid conditions, and electrolyte disturbances. Result There was a high incidence of Mg disturbances at admission among patients admitted to the ICU. The incidence of hypomagnesemia and hypermagnesemia was 40.9 and 13.9% respectively. The mean Mg level among patients who expired was 1.55 ± 0.68 mg/dL, and the association with outcome was found to be statistically significant (p = 0.001).Hypomagnesemia (HypoMg) was associated with significantly higher mortality (51.3%) as compared to normomagnesemia (NormoMg) (29.3%) and hypermagnesemia (HyperMg) (23.1%) (HypoMg vs NormoMg, HypoMg vs HyperMg, p = 0.001, 0.002 respectively). The need for mechanical ventilation was significantly higher in hypomagnesemic as compared to hypermagnesemia patients (p = 0.012). The association of baseline APACHE II and SOFA scores with serum Mg levels was statistically significant (p = 0.001 and 0.002 respectively).The incidence of gastrointestinal disorders was significantly higher among hypomagnesemia patients (HypoMg vs NormoMg, p = 0.023), while chronic kidney disease was significantly higher in hypermagnesemic patients (HypoMg vs HyperMg, p = 0.0009, NormoMg vs HyperMg, p = 0.0004). On comparing the incidence of electrolyte disorders between HypoMg, NormoMg, and HyperMg groups, it was found that hypokalemia and hypocalcemia (p = 0.0003 and 0.039 respectively) were associated with hypomagnesemia and hyperkalemia and hypercalcemia (p = 0.001 and 0.005 respectively) were associated with hypermagnesemia. Conclusion Our study highlights the role of Mg monitoring in critically ill patients admitted to the ICU and its value for a favorable outcome. We found that hypomagnesemia was significantly associated with adverse outcomes and higher mortality in critically ill patients. Intensivists should maintain a high index of suspicion for Mg disturbances and evaluate patients appropriately. How to cite this article Gonuguntla V, Talwar V, Krishna B, Srinivasan G. Correlation of Serum Magnesium Levels with Clinical Outcome: A Prospective Observational Study in Critically Ill Patients Admitted to a Tertiary Care ICU in India. Indian J Crit Care Med 2023;27(5):342-347.
Collapse
Affiliation(s)
- Vineesha Gonuguntla
- Department of Anaesthesia and Critical Care, Safdarjung Hospital, New Delhi, India
| | - Vandana Talwar
- Department of Anaesthesia and Critical Care, Vardhman Mahavir Medical College & Safdarjang Hospital, New Delhi, India
| | - Bhavya Krishna
- Department of Anaesthesia and Critical Care, Vardhman Mahavir Medical College & Safdarjang Hospital, New Delhi, India
| | - Gautham Srinivasan
- Department of Anaesthesia and Critical Care, Glenfield Hospital, Leicester, United Kingdom
| |
Collapse
|
3
|
Eltan M, Yavas Abali Z, Turkyilmaz A, Gokce I, Abali S, Alavanda C, Arman A, Kirkgoz T, Guran T, Hatun S, Bereket A, Turan S. Familial Hypomagnesemia with Hypercalciuria and Nephrocalcinosis Due to CLDN16 Gene Mutations: Novel Findings in Two Cases with Diverse Clinical Features. Calcif Tissue Int 2022; 110:441-450. [PMID: 34761296 DOI: 10.1007/s00223-021-00928-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/01/2021] [Indexed: 11/28/2022]
Abstract
Biallelic loss of function mutations in the CLDN16 gene cause familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC), and chronic kidney disease. Here we report two cases of FHHNC with diverse clinical presentations and hypercalcemia in one as a novel finding. Pt#1 initially presented with urinary tract infection and failure to thrive at 5.5 months of age to another center. Bilateral nephrocalcinosis, hypercalcemia (Ca: 12.2 mg/dl), elevated parathyroid hormone (PTH) level, and hypercalciuria were detected. Persistently elevated PTH with high/normal Ca levels led to subtotal-parathyroidectomy at the age of 2.5. However, PTH levels remained elevated with progressive deterioration in renal function. At 9-year-old, she was referred to us for evaluation of hyperparathyroidism and, hypomagnesemia together with hypercalciuria, elevated PTH with normal Ca levels, and medullary nephrocalcinosis were detected. Compound heterozygosity of CLDN16 variants (c.715G>A, p.G239R; and novel c.360C>A, p.C120*) confirmed the diagnosis. Pt#2 was a 10-month-old boy, admitted with irritability and urinary crystals. Hypocalcemia, hypophosphatemia, elevated PTH and ALP, low 25(OH)D levels, and radiographic findings of rickets were detected. However, additional findings of hypercalciuria and bilateral nephrocalcinosis were inconsistent with the nutritional rickets. Low/normal serum Mg levels suggested the diagnosis of FHHNC which was confirmed genetically as a homozygous missense (c.602G > A; p.G201E) variant in CLDN16. Yet, hypocalcemia and hypomagnesemia persisted in spite of treatment. In conclusion, FHHNC may present with diverse clinical features with mild hypomagnesemia leading to secondary hyperparathyroidism with changing Ca levels from low to high. Early and accurate clinical and molecular genetic diagnosis is important for proper management.
Collapse
Affiliation(s)
- Mehmet Eltan
- Department of Pediatric Endocrinology and Diabetes, School of Medicine, Marmara University, Fevzi Çakmak Mahallesi, Muhsin Yazıcıoglu Caddesi, No:10, 34899, Pendik Istanbul, Turkey
| | - Zehra Yavas Abali
- Department of Pediatric Endocrinology and Diabetes, School of Medicine, Marmara University, Fevzi Çakmak Mahallesi, Muhsin Yazıcıoglu Caddesi, No:10, 34899, Pendik Istanbul, Turkey
| | - Ayberk Turkyilmaz
- Department of Medical Genetics, School of Medicine, Marmara University, Istanbul, Turkey
| | - Ibrahim Gokce
- Department of Pediatric Nephrology, School of Medicine, Marmara University, Istanbul, Turkey
| | - Saygın Abali
- Department of Pediatric Endocrinology and Diabetes, School of Medicine, Marmara University, Fevzi Çakmak Mahallesi, Muhsin Yazıcıoglu Caddesi, No:10, 34899, Pendik Istanbul, Turkey
| | - Ceren Alavanda
- Department of Medical Genetics, School of Medicine, Marmara University, Istanbul, Turkey
| | - Ahmet Arman
- Department of Medical Genetics, School of Medicine, Marmara University, Istanbul, Turkey
| | - Tarik Kirkgoz
- Department of Pediatric Endocrinology and Diabetes, School of Medicine, Marmara University, Fevzi Çakmak Mahallesi, Muhsin Yazıcıoglu Caddesi, No:10, 34899, Pendik Istanbul, Turkey
| | - Tulay Guran
- Department of Pediatric Endocrinology and Diabetes, School of Medicine, Marmara University, Fevzi Çakmak Mahallesi, Muhsin Yazıcıoglu Caddesi, No:10, 34899, Pendik Istanbul, Turkey
| | - Sukru Hatun
- Department of Pediatric Endocrinology and Diabetes, School of Medicine, Koc University, Istanbul, Turkey
| | - Abdullah Bereket
- Department of Pediatric Endocrinology and Diabetes, School of Medicine, Marmara University, Fevzi Çakmak Mahallesi, Muhsin Yazıcıoglu Caddesi, No:10, 34899, Pendik Istanbul, Turkey
| | - Serap Turan
- Department of Pediatric Endocrinology and Diabetes, School of Medicine, Marmara University, Fevzi Çakmak Mahallesi, Muhsin Yazıcıoglu Caddesi, No:10, 34899, Pendik Istanbul, Turkey.
| |
Collapse
|
4
|
Peride I, Tiglis M, Neagu TP, Niculae A, Checherita IA. Magnesium—A More Important Role in CKD–MBD than We Thought. Diagnostics (Basel) 2022; 12:diagnostics12040880. [PMID: 35453928 PMCID: PMC9031465 DOI: 10.3390/diagnostics12040880] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/13/2022] [Accepted: 03/30/2022] [Indexed: 12/17/2022] Open
Abstract
Chronic kidney disease (CKD) is associated with different complications, including chronic kidney disease–mineral and bone disorder (CKD–MBD), which represents a systemic disorder that involves the presence of different mineral or bone structure abnormalities (i.e., modification of bone turnover, strength, volume, etc.), including even vascular calcification development. Even if, over the years, different pathophysiological theories have been developed to explain the onset and progression of CKD–MBD, the influence and importance of serum magnesium level on the evolution of CKD have only recently been highlighted. So far, data are inconclusive and conflicting; therefore, further studies are necessary to validate these findings, which could be useful in developing a better, more adequate, and personalized management of CKD patients.
Collapse
Affiliation(s)
- Ileana Peride
- Clinical Department No. 3, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
- Correspondence: (I.P.); (A.N.)
| | - Mirela Tiglis
- Clinical Department No. 14, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
| | - Tiberiu Paul Neagu
- Clinical Department No. 11, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
| | - Andrei Niculae
- Clinical Department No. 3, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
- Correspondence: (I.P.); (A.N.)
| | - Ionel Alexandru Checherita
- Clinical Department No. 3, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
| |
Collapse
|
5
|
Sirikul W, Siri-Angkul N, Chattipakorn N, Chattipakorn SC. Fibroblast Growth Factor 23 and Osteoporosis: Evidence from Bench to Bedside. Int J Mol Sci 2022; 23:ijms23052500. [PMID: 35269640 PMCID: PMC8909928 DOI: 10.3390/ijms23052500] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 02/05/2023] Open
Abstract
Osteoporosis is a chronic debilitating disease caused by imbalanced bone remodeling processes that impair the structural integrity of bone. Over the last ten years, the association between fibroblast growth factor 23 (FGF23) and osteoporosis has been studied in both pre-clinical and clinical investigations. FGF23 is a bone-derived endocrine factor that regulates mineral homeostasis via the fibroblast growth factor receptors (FGFRs)/αKlotho complex. These receptors are expressed in kidney and the parathyroid gland. Preclinical studies have supported the link between the local actions of FGF23 on the bone remodeling processes. In addition, clinical evidence regarding the effects of FGF23 on bone mass and fragility fractures suggest potential diagnostic and prognostic applications of FGF23 in clinical contexts, particularly in elderly and patients with chronic kidney disease. However, inconsistent findings exist and there are areas of uncertainty requiring exploration. This review comprehensively summarizes and discusses preclinical and clinical reports on the roles of FGF23 on osteoporosis, with an emphasis on the local action, as opposed to the systemic action, of FGF23 on the bone. Current gaps in knowledge and future research directions are also suggested to encourage further rigorous research in this important field.
Collapse
Affiliation(s)
- Wachiranun Sirikul
- Department of Community Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Natthaphat Siri-Angkul
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; (N.S.-A.); (N.C.)
- Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Nipon Chattipakorn
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; (N.S.-A.); (N.C.)
- Cardiac Electrophysiology Unit, Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Siriporn C. Chattipakorn
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; (N.S.-A.); (N.C.)
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai 50200, Thailand
- Department of Oral Biology and Diagnostic Sciences, Faculty of Dentistry, Chiang Mai University, Chiang Mai 50200, Thailand
- Correspondence: ; Tel.: +66-53-944-451; Fax: +66-53-222-844
| |
Collapse
|
6
|
Møller AS, Bressendorff I, Nordholm A, Egstrand S, Jørgensen NR, Klausen TW, Olgaard K, Hansen D. Diurnal variation of magnesium and the mineral metabolism in patients with chronic kidney disease. Bone Rep 2021; 15:101130. [PMID: 34584906 PMCID: PMC8453182 DOI: 10.1016/j.bonr.2021.101130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/25/2021] [Accepted: 09/11/2021] [Indexed: 02/08/2023] Open
Abstract
Increasing levels of magnesium in blood are associated with reduced risk of cardiovascular disease in chronic kidney disease (CKD). Magnesium supplementation may reduce the progression of vascular calcification in CKD. The diurnal pattern and effect of fasting on magnesium in blood and urine in CKD is unknown, and knowledge of this may influence management of magnesium supplementation. We included ten patients with CKD stage four without diabetes mellitus and ten healthy controls. Participants were admitted to our hospital ward for a 24-h study period. Blood and urine samples were collected in a non-fasting state at 8 o'clock in the morning and every third hour hereafter until the final samples in a fasting state at 8 o'clock the following morning. We found no diurnal variation in plasma magnesium (p = 0.097) in either group, but a significant diurnal variation in urinary excretion of magnesium (p = 0.044) in both CKD and healthy controls with no significant interaction between the two groups, and thus no suggestion that CKD affects diurnal variation of plasma magnesium or urinary magnesium excretion. The levels of plasma magnesium were not significantly different in fasting and non-fasting conditions. Magnesium in plasma does not display a significant diurnal variation and can be measured at any time of day and in both fasting and non-fasting conditions. Urinary magnesium excretion displays diurnal variation, which is likely related to increased uptake of magnesium during meals and helps maintain a stable concentration of magnesium in blood.
Collapse
Affiliation(s)
- Astrid Sand Møller
- Department of Nephrology, Herlev and Gentofte Hospital, DK-2730 Herlev, Denmark
| | - Iain Bressendorff
- Department of Nephrology, Herlev and Gentofte Hospital, DK-2730 Herlev, Denmark
| | - Anders Nordholm
- Department of Nephrology, Herlev and Gentofte Hospital, DK-2730 Herlev, Denmark
- Department of Nephrology, Rigshospitalet, DK-2100 Copenhagen, Denmark
| | - Søren Egstrand
- Department of Nephrology, Herlev and Gentofte Hospital, DK-2730 Herlev, Denmark
- Department of Nephrology, Rigshospitalet, DK-2100 Copenhagen, Denmark
| | - Niklas R. Jørgensen
- Department of Clinical Biochemistry, Rigshospitalet, DK-2600 Glostrup, Denmark
- Department of Clinical Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Tobias W. Klausen
- Department of Hematology, Herlev and Gentofte Hospital, DK-2730 Herlev, Denmark
| | - Klaus Olgaard
- Department of Nephrology, Rigshospitalet, DK-2100 Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Ditte Hansen
- Department of Nephrology, Herlev and Gentofte Hospital, DK-2730 Herlev, Denmark
- Department of Clinical Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| |
Collapse
|
7
|
Grigoryan R, Costas-Rodríguez M, Van Wonterghem E, Vandenbroucke RE, Vanhaecke F. Effect of Endotoxemia Induced by Intraperitoneal Injection of Lipopolysaccharide on the Mg isotopic Composition of Biofluids and Tissues in Mice. Front Med (Lausanne) 2021; 8:664666. [PMID: 34368182 PMCID: PMC8342922 DOI: 10.3389/fmed.2021.664666] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 06/22/2021] [Indexed: 12/02/2022] Open
Abstract
Endotoxemia induced in vivo in mice by intraperitoneal injection of lipopolysaccharide (LPS) leads to (neuro)inflammation and sepsis. Also the homeostasis of mineral elements can be altered through mechanisms that still are poorly understood. The isotopic composition of Mg and the concentrations of the minor elements Ca, K, Mg, Na, P, and S were determined in biological fluids and tissues of young (14–28 weeks) and aged (40–65 weeks) LPS-injected mice and age-matched controls to reveal potential effects of the LPS-induced infection. Blood plasma of young and aged LPS-injected mice showed a heavy Mg isotopic composition, as well as elevated Mg and P concentrations, compared to matched controls. The plasma Mg isotopic composition was correlated with the P concentration in aged mice. Also the liver Mg isotopic composition was strongly affected in the young and aged LPS-injected mice, while for aged mice, an additional effect on the urine Mg isotopic composition was established. These observations were hypothetically associated with liver inflammation and/or hepatotoxicity, and reduced urinary Mg excretion, respectively. Also a regional endotoxin-induced difference was observed in the brain Mg isotopic composition for the aged mice only, and was attributed to potential disruption of the blood-brain barrier.
Collapse
Affiliation(s)
- Rosa Grigoryan
- Atomic & Mass Spectrometry - A&MS Research Unit, Department of Chemistry, Ghent University, Ghent, Belgium
| | - Marta Costas-Rodríguez
- Atomic & Mass Spectrometry - A&MS Research Unit, Department of Chemistry, Ghent University, Ghent, Belgium
| | - Elien Van Wonterghem
- Atomic & Mass Spectrometry - A&MS Research Unit, Department of Chemistry, Ghent University, Ghent, Belgium
| | - Roosmarijn E Vandenbroucke
- Vlaams Instituut voor Biotechnologie (VIB) Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Frank Vanhaecke
- Atomic & Mass Spectrometry - A&MS Research Unit, Department of Chemistry, Ghent University, Ghent, Belgium
| |
Collapse
|
8
|
Schumacher SA, Kamr AM, Lakritz J, Burns TA, Bertone AL, Toribio RE. Effects of intravenous magnesium sulfate on serum calcium-regulating hormones and plasma and urinary electrolytes in healthy horses. PLoS One 2021; 16:e0247542. [PMID: 34181644 PMCID: PMC8238178 DOI: 10.1371/journal.pone.0247542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 05/21/2021] [Indexed: 11/29/2022] Open
Abstract
Intravenous magnesium sulfate (MgSO4) is used in equine practice to treat hypomagnesemia, dysrhythmias, neurological disorders, and calcium dysregulation. MgSO4 is also used as a calming agent in equestrian events. Hypercalcemia affects calcium-regulating hormones, as well as plasma and urinary electrolytes; however, the effect of hypermagnesemia on these variables is unknown. The goal of this study was to investigate the effect of hypermagnesemia on blood parathyroid hormone (PTH), calcitonin (CT), ionized calcium (Ca2+), ionized magnesium (Mg2+), sodium (Na+), potassium (K+), chloride (Cl-) and their urinary fractional excretion (F) after intravenous administration of MgSO4 in healthy horses. Twelve healthy female horses of 4–18 years of age and 432–600 kg of body weight received a single intravenous dose of MgSO4 (60 mg/kg) over 5 minutes, and blood and urine samples were collected at different time points over 360 minutes. Plasma Mg2+ concentrations increased 3.7-fold over baseline values at 5 minutes and remained elevated for 120 minutes (P < 0.05), Ca2+ concentrations decreased from 30–60 minutes (P < 0.05), but Na+, K+ and Cl- concentrations did not change. Serum PTH concentrations dropped initially to rebound and remain elevated from 30 to 60 minutes, while CT concentrations increased at 5 minutes to return to baseline by 10 minutes (P < 0.05). The FMg, FCa, FNa, FK, and FCl increased, while urine osmolality decreased from 30–60 minutes compared baseline (P < 0.05). Short-term experimental hypermagnesemia alters calcium-regulating hormones (PTH, CT), reduces plasma Ca2+ concentrations, and increases the urinary excretion of Mg2+, Ca2+, K+, Na+ and Cl- in healthy horses. This information has clinical implications for the short-term effects of hypermagnesemia on calcium-regulation, electrolytes, and neuromuscular activity, in particular with increasing use of Mg salts to treat horses with various acute and chronic conditions as well as a calming agent in equestrian events.
Collapse
Affiliation(s)
- Stephen A. Schumacher
- College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States of America
- United States Equestrian Federation, Columbus, Ohio, United States of America
| | - Ahmed M. Kamr
- College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States of America
- Faculty of Veterinary Medicine, University of Sadat City, Sadat City, Egypt
| | - Jeffrey Lakritz
- College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States of America
| | - Teresa A. Burns
- College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States of America
| | - Alicia L. Bertone
- College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States of America
| | - Ramiro E. Toribio
- College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States of America
- * E-mail:
| |
Collapse
|
9
|
Tsai WH, Lee CC, Cheng SP, Zeng YH. Hyperparathyroidism presenting as hyperemesis and acute pancreatitis in pregnancy: A case report. Medicine (Baltimore) 2021; 100:e25451. [PMID: 33832152 PMCID: PMC8036029 DOI: 10.1097/md.0000000000025451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 12/08/2020] [Indexed: 01/05/2023] Open
Abstract
RATIONALE Nausea and vomiting are common in the early period of pregnancy and rarely seen as an overture to pancreatitis. PATIENT CONCERNS Here, we describe a 31-year-old pregnant woman who presented with progressive nausea and vomiting followed by severe epigastric pain. Biochemical data and sonographic features confirmed the occurrence of acute pancreatitis. Accompanying electrolyte abnormalities included hypercalcemia and hypokalemia. Her condition stabilized following medical treatment, but hypercalcemia persisted despite intravenous fluids and furosemide administration. DIAGNOSES A diagnosis of primary hyperparathyroidism was made based on the elevated parathyroid hormone level and urinary calcium-to-creatinine clearance ratio. INTERVENTIONS Localization study with neck ultrasonography indicated left inferior parathyroid adenoma. She underwent parathyroidectomy successfully and made an uneventful recovery. OUTCOMES At 37 weeks of gestation, she had a serum calcium level of 8.8 mg/dL and normal parathyroid hormone of 28.55 pg/mL. A healthy baby weighing 3180 g was delivered smoothly with no clinical nor biochemical evidence of hypocalcemia. LESSONS Although primary hyperparathyroidism during pregnancy is usually asymptomatic, patients may present with atypical manifestations such as hyperemesis and pancreatitis. Proper diagnosis and timely intervention are crucial to minimizing potential hazards to both mother and fetus.
Collapse
Affiliation(s)
- Wen-Hsuan Tsai
- Division of Endocrinology and Metabolism, Department of Internal Medicine MacKay Memorial Hospital, Taipei
| | - Chun-Chuan Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine MacKay Memorial Hospital, Taipei
- Department of Medicine, MacKay Medical College, New Taipei City
| | - Shih-Ping Cheng
- Department of Surgery, MacKay Memorial Hospital, Taipei, Taiwan ROC
| | - Yi-Hong Zeng
- Division of Endocrinology and Metabolism, Department of Internal Medicine MacKay Memorial Hospital, Taipei
- Department of Medicine, MacKay Medical College, New Taipei City
| |
Collapse
|
10
|
Wang R, Chen J, Ding F, Zhang L, Wu X, Wan Y, Hu J, Zhang X, Wu Q. Renal tubular injury induced by glyphosate combined with hard water: the role of cytosolic phospholipase A2. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:130. [PMID: 33569432 PMCID: PMC7867956 DOI: 10.21037/atm-20-7739] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Background The combined effects of glyphosate and hard water on chronic kidney disease of unknown etiology (CDKu) have attracted much interest, but the mechanisms remain unknown. Cytoplasmic phospholipase A2 (cPLA2) plays a key role in the acute and chronic inflammatory reactions. This study explored the effect of glyphosate combined with hard water on renal tubules and the possible targets and mechanisms involved. Methods In vivo experiments were conducted to investigate the synergistic effects and potential mechanisms of glyphosate and hard water on renal tubular injury in mice. Results Administration of glyphosate in mice resulted in elevated levels of β2-microglobulin (β2-MG), albumin (ALB), and serum creatinine (SCr) compared to control mice. This increase was more pronounce when glyphosate was combined with hard water. In the glyphosate-treated mice, small areas of the kidney revealed fibroblast proliferation and vacuolar degeneration, particularly at the higher dose of 400 mg/kg glyphosate. However, the combination of glyphosate and hard water induced an even greater degree of pathological changes in the kidney. Immunofluorescence and western blot analyses showed that glyphosate and hard water had a coordinated effect on calcium ions (Ca2+)-activated phospholipase A2 and the activation may play a key role in inflammation and renal tubular injury. Exposure to glyphosate alone or glyphosate plus hard water increased the levels of oxidative stress markers and inflammatory biomarkers, namely, thromboxane A2 (TX-A2), leukotriene B4 (LTB4), prostaglandin E2 (PGE2), nitric oxide synthase (NOS), and nitric oxide (NO). Parameters of oxidative stress, including the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were decreased. Further analysis showed that the levels of these biomarkers were significantly different between the mice treated with glyphosate plus hard water and the mice treated with glyphosate alone. Conclusions These findings suggested that hard water combined with glyphosate can induce renal tubular injury in mice, and this may involve mitogen-activated protein kinases (MAPK)/cytosolic phospholipase A2 (cPLA2)/arachidonic acid (AA) and its downstream factors.
Collapse
Affiliation(s)
- Ruojing Wang
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, China
| | - Jing Chen
- Department of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Fan Ding
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, China
| | - Lin Zhang
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, China
| | - Xuan Wu
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, China
| | - Yi Wan
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Jianying Hu
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Xiaoyan Zhang
- Department of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Qing Wu
- School of Public Health and Key Laboratory of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, China
| |
Collapse
|
11
|
Chanpaisaeng K, Teerapornpuntakit J, Wongdee K, Charoenphandhu N. Emerging roles of calcium-sensing receptor in the local regulation of intestinal transport of ions and calcium. Am J Physiol Cell Physiol 2020; 320:C270-C278. [PMID: 33356945 DOI: 10.1152/ajpcell.00485.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Whether the intestinal mucosal cells are capable of sensing calcium concentration in the lumen and pericellular interstitium remains enigmatic for decades. Most calcium-regulating organs, such as parathyroid gland, kidney, and bone, are capable of using calcium-sensing receptor (CaSR) to detect plasma calcium and trigger appropriate feedback responses to maintain calcium homeostasis. Although both CaSR transcripts and proteins are abundantly expressed in the crypt and villous enterocytes of the small intestine as well as the surface epithelial cells of the large intestine, the studies of CaSR functions have been limited to amino acid sensing and regulation of epithelial fluid secretion. Interestingly, several lines of recent evidence have indicated that the enterocytes use CaSR to monitor luminal and extracellular calcium levels, thereby reducing the activity of transient receptor potential channel, subfamily V, member 6, and inducing paracrine and endocrine feedback responses to restrict calcium absorption. Recent investigations in zebra fish and rodents have also suggested the role of fibroblast growth factor (FGF)-23 as an endocrine and/or paracrine factor participating in the negative control of intestinal calcium transport. In this review article, besides the CaSR-modulated ion transport, we elaborate the possible roles of CaSR and FGF-23 as well as their crosstalk as parts of a negative feedback loop for counterbalancing the seemingly unopposed calciotropic effect of 1,25-dihydroxyvitamin D3 on the intestinal calcium absorption.
Collapse
Affiliation(s)
- Krittikan Chanpaisaeng
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Functional Ingredients and Food Innovation Research Group, National Center for Genetic Engineering and Biotechnology (BIOTEC), Pathum Thani, Thailand
| | - Jarinthorn Teerapornpuntakit
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Kannikar Wongdee
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Faculty of Allied Health Sciences, Burapha University, Chonburi, Thailand
| | - Narattaphol Charoenphandhu
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand.,Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand.,The Academy of Science, The Royal Society of Thailand, Bangkok, Thailand
| |
Collapse
|
12
|
Ferdaus MZ, Gratreak BDK, Miller L, Si J, McCormick JA, Yang C, Ellison DH, Terker AS. WNK4 limits distal calcium losses following acute furosemide treatment. Physiol Rep 2019; 7:e14195. [PMID: 31496133 PMCID: PMC6732491 DOI: 10.14814/phy2.14195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 06/26/2019] [Accepted: 06/27/2019] [Indexed: 01/05/2023] Open
Abstract
The distal nephron is essential for calcium homeostasis. This is evidenced by disordered calcium transport following disrupted distal nephron function occurring in salt-wasting tubulopathies or with diuretic use. A plethora of studies support a role for WNK4 in thick ascending limb (TAL) and distal convoluted tubule ion transport with most studies focusing on sodium transport. Little is known about the in vivo role of WNK4 in regulating calcium homeostsis. Here, we investigated the role of WNK4 in regulating distal nephron calcium transport using WNK4 knockout animals (WNK4-/- ). As has been shown previously, we found that baseline urinary calcium levels are normal following WNK4 deletion. Following acute treatment with the loop diuretic, furosemide, which causes hypercalciuria through TAL inhibition, WNK4-/- animals demonstrated increased calcium wasting compared with wild-type controls. WNK4-/- animals had decreased TRPV5 expression along DCT2 supporting a mechanistic role for this calcium channel in the increased calciuresis. As this supported the hypothesis that WNK4-/- animals have a tendency toward calcium wasting under stress, we tested the effects of a calcium-deplete diet on urinary calcium excretion. Urinary calcium excretion and plasma ionized calcium levels were not different between control and knockout animals following consumption of a calcium-deplete diet. Our data show that WNK4, via regulation of TRPV5, limits distal calcium losses following acute treatment with furosemide; however, WNK4 deletion does not affect the chronic renal response to dietary calcium depletion. Our data reveal an in vivo role for WNK4 in distal nephron calcium handling that is important for fine-tuning calcium reabsorption.
Collapse
Affiliation(s)
| | | | - Lauren Miller
- Division of NephrologyOregon Health and Science UniversityPortlandOregon
| | - Jinge Si
- Division of NephrologyOregon Health and Science UniversityPortlandOregon
| | - James A. McCormick
- Division of NephrologyOregon Health and Science UniversityPortlandOregon
| | - Chao‐Ling Yang
- Division of NephrologyOregon Health and Science UniversityPortlandOregon
| | - David H. Ellison
- Division of NephrologyOregon Health and Science UniversityPortlandOregon
- Oregon Clinical and Translational Research Institute, Oregon Health and Science UniversityPortlandOregon
| | - Andrew S. Terker
- Division of NephrologyOregon Health and Science UniversityPortlandOregon
- Division of NephrologyVanderbilt University Medical CenterNashvilleTennessee
| |
Collapse
|
13
|
Meurer M, Höcherl K. Deregulated renal magnesium transport during lipopolysaccharide-induced acute kidney injury in mice. Pflugers Arch 2019; 471:619-631. [PMID: 30726531 DOI: 10.1007/s00424-019-02261-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 01/13/2019] [Accepted: 01/24/2019] [Indexed: 02/06/2023]
Abstract
Magnesium (Mg2+) abnormalities during sepsis have been reported, but the underlying mechanisms during acute inflammation are poorly understood. We hypothesized that a decrease in GFR and/or changes in transporters or channels for Mg2+ could be responsible for the observed Mg2+ abnormalities. Therefore, we studied the metabolism of Mg2+ in a murine model of endotoxemia. LPS-induced hypermagnesemia was paralleled by a decrease in creatinine clearance and an increase in the fractional excretion of Mg2+. In agreement with an altered renal Mg2+ handling, endotoxemia decreased the renal expression of claudin (Cldn) 10b, Cldn16, Cldn19, parvalbumin, and of the solute carrier family (Slc) 41a3. Further, LPS increased the renal expression of Cldn14 and Slc41a1. The renal expression of the transient receptor potential melastin (Trpm) 6, Trpm7, and of cyclin M (Cnnm) 2 was unaltered in response to LPS. In vitro studies support a direct effect on the expression of Cldn10b, Cldn14, Cldn16, and Cldn19. Further, endotoxemia increased the fractional excretion of sodium, which was paralleled by a decrease of important renal sodium transporters. In the large intestine, the expression of Trpm7 was increased in response to LPS, whereas the expression of Trpm6 was decreased. Cnnm4 mRNA levels were unchanged in the large intestine. Further, Cldn12 and Na+-H+ exchanger 3 (Slc9a3) expressions were decreased in the small intestine in response to LPS. Our findings indicate that endotoxemia is associated with hypermagnesemia and a disturbed Mg2+ handling. It seems likely that LPS-induced hypermagnesemia is due to the decrease in renal function in response to LPS.
Collapse
Affiliation(s)
- Manuel Meurer
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Fahrstr. 17, 91054, Erlangen, Germany
| | - Klaus Höcherl
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Fahrstr. 17, 91054, Erlangen, Germany.
| |
Collapse
|
14
|
Basok AB, Rogachev B, Haviv YS, Vorobiov M. Treatment of extreme hypercalcaemia: the role of haemodialysis. BMJ Case Rep 2018; 2018:bcr-2017-223772. [PMID: 29866671 PMCID: PMC5990060 DOI: 10.1136/bcr-2017-223772] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A patient with extremely high calcium level of 23.9 mg/dL (5.97 mmol/L) was admitted to our department unconscious with pathological ECG recording, demonstrating shortening of QT interval. The patient was treated by fluid resuscitation, bisphosphonates, salmon calcitonin and steroids. Haemodialysis with low calcium bath had been promptly provided with improvement of consciousness and calcium level. ECG changes disappeared. Subsequent investigations revealed hyperparathyroidism and a large parathyroid adenoma was then surgically removed. Extreme and rapid calcium elevation (parathyroid crisis) is rarely seen in primary hyperparathyroidism and usually is distinctive for malignancy. In the context of acute kidney injury and refractory hypercalcaemia with life-threatening complications (coma, ECG changes with impending danger of arrhythmia), haemodialysis may effectively decrease calcium levels. It should be pointed out that dialysis is an efficient method of treatment of refractory hypercalcaemia, parathyroid crisis, but it is rarely used due to its invasive nature.
Collapse
Affiliation(s)
- Anna B Basok
- Department of Nephrology, Soroka University Medical Center, Beer Sheva, Israel
| | - Boris Rogachev
- Department of Nephrology, Soroka University Medical Center, Beer Sheva, Israel
| | - Yosef Shmuel Haviv
- Department of Nephrology, Soroka University Medical Center, Beer Sheva, Israel
| | - Marina Vorobiov
- Department of Nephrology, Soroka University Medical Center, Beer Sheva, Israel
| |
Collapse
|
15
|
Abstract
Magnesium (Mg2+) is an essential mineral without known specific regulatory mechanisms. In ruminants, plasma Mg2+ concentration depends primarily on the balance between Mg2+ absorption and Mg2+ excretion. The primary site of Mg2+ absorption is the rumen, where Mg2+ is apically absorbed by both potential-dependent and potential-independent uptake mechanisms, reflecting involvement of ion channels and electroneutral transporters, respectively. Transport is energised in a secondary active manner by a basolateral Na+/Mg2+ exchanger. Ruminal transport of Mg2+ is significantly influenced by a variety of factors such as high K+ concentration, sudden increases of ammonia, pH, and the concentration of SCFA. Impaired Mg2+ absorption in the rumen is not compensated for by increased transport in the small or large intestine. While renal excretion can be adjusted to compensate precisely for any surplus in Mg2+ uptake, a shortage in dietary Mg2+ cannot be compensated for either via skeletal mobilisation of Mg2+ or via up-regulation of ruminal absorption. In such situations, hypomagnesaemia will lead to decrease of a Mg2+ in the cerebrospinal fluid and clinical manifestations of tetany. Improved knowledge concerning the factors governing Mg2+ homeostasis will allow reliable recommendations for an adequate Mg2+ intake and for the avoidance of possible disturbances. Future research should clarify the molecular identity of the suggested Mg2+ transport proteins and the regulatory mechanisms controlling renal Mg excretion as parameters influencing Mg2+ homeostasis.
Collapse
|
16
|
Abstract
OBJECTIVES Hypomagnesemia is common among hospitalized patients, particularly those who are critically ill. It can be associated with a number of potentially life-threatening cardiovascular, neurological and behavioral manifestations. As opposed to acute, chronic hypomagnesemia is often underdiagnosed and underreported and as such may pose a diagnostic and therapeutic problem. CASE PRESENTATION We describe a case of magnesium wasting in a middle-aged woman with head and neck cancer who presented with recurrent syncopal episodes complicated by a femur fracture 4 months after completing a course of carboplatin-containing chemotherapy. Fractional excretion of magnesium of 16% was consistent with renal wasting of magnesium. After ruling out all common causes of hypomagnesemia, it was concluded that she sustained carboplatin-induced renal tubular damage making her relatively resistant to magnesium supplementation. CONCLUSION Several antineoplastic agents have been linked to chronic hypomagnesemia including anti-epidermal growth factor receptor agents such as cetuximab and panitumumab, cyclosporine, and the platinum-based agents cisplatin and carboplatin. The example case presented here illustrates the importance of chronic hypomagnesemia and its possible debilitating effects following carboplatin-containing chemotherapy. A growing numbers of cancer survivors are treated with these antineoplastic agents, and are hospitalized for non-cancer-related problems. These patients may have prolonged hypomagnesemia, and hence pose a diagnostic dilemma. We review the pathophysiology, etiology, diagnosis, clinical manifestations, monitoring and treatment of hypomagnesemia, with special attention to mechanisms of renal damage caused by platinum-containing chemotherapeutic agents.
Collapse
Affiliation(s)
- Marko Velimirovic
- a Hospital Medicine Unit, Massachusetts General Hospital , Boston , MA , USA
- b Harvard Medical School , Boston , MA , USA
| | - Joshua Charles Ziperstein
- a Hospital Medicine Unit, Massachusetts General Hospital , Boston , MA , USA
- b Harvard Medical School , Boston , MA , USA
| | - Andrew Zoltan Fenves
- a Hospital Medicine Unit, Massachusetts General Hospital , Boston , MA , USA
- b Harvard Medical School , Boston , MA , USA
| |
Collapse
|
17
|
Bonjour JP. The dietary protein, IGF-I, skeletal health axis. Horm Mol Biol Clin Investig 2017; 28:39-53. [PMID: 26985688 DOI: 10.1515/hmbci-2016-0003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 02/12/2016] [Indexed: 12/29/2022]
Abstract
Dietary protein represents an important nutrient for bone health and thereby for the prevention of osteoporosis. Besides its role as a brick provider for building the organic matrix of skeletal tissues, dietary protein stimulates the production of the anabolic bone trophic factor IGF-I (insulin-like growth factor I). The liver is the main source of circulating IGF-I. During growth, protein undernutrition results in reduced bone mass and strength. Genetic defect impairing the production of IGF-I markedly reduces bone development in both length and width. The serum level of IGF-I markedly increases and then decreases during pubertal maturation in parallel with the change in bone growth and standing height velocity. The impact of physical activity on bone structure and strength is enhanced by increased dietary protein consumption. This synergism between these two important environmental factors can be observed in prepubertal boys, thus modifying the genetically determined bone growth trajectory. In anorexia nervosa, IGF-I is low as well as bone mineral mass. In selective protein undernutrition, there is a resistance to the exogenous bone anabolic effect of IGF-I. A series of animal experiments and human clinical trials underscore the positive effect of increased dietary intake of protein on calcium-phosphate economy and bone balance. On the contrary, the dietary protein-induced acidosis hypothesis of osteoporosis is not supported by several experimental and clinical studies. There is a direct effect of amino acids on the local production of IGF-I by osteoblastic cells. IGF-I is likely the main mediator of the positive effect of parathyroid hormone (PTH) on bone formation, thus explaining the reduction in fragility fractures as observed in PTH-treated postmenopausal women. In elderly women and men, relatively high protein intake protects against spinal and femoral bone loss. In hip fracture patients, isocaloric correction of the relatively low protein intake results in: increased IGF-I serum level, significant attenuation of postsurgical bone loss, improved muscle strength, better recovery, and shortened hospital stay. Thus, dietary protein contributes to bone health from early childhood to old age. An adequate intake of protein should be recommended in the prevention and treatment of osteoporosis.
Collapse
|
18
|
Xu LHR, Maalouf NM. Effect of acute hyperinsulinemia on magnesium homeostasis in humans. Diabetes Metab Res Rev 2017; 33. [PMID: 27546733 DOI: 10.1002/dmrr.2844] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 07/03/2016] [Accepted: 08/01/2016] [Indexed: 12/23/2022]
Abstract
BACKGROUND Insulin may influence magnesium homeostasis through multiple mechanisms. Acutely, it stimulates the shift of magnesium from plasma into red blood cells and platelets, and in vitro, it stimulates the activity of the TRPM6 channel, a key regulator of renal magnesium reabsorption. We investigated the impact of hyperinsulinemia on magnesium handling in participants with a wide range of insulin sensitivity. METHOD Forty-seven participants were recruited, including 34 nondiabetic controls and 13 with type 2 diabetes mellitus. After stabilization under fixed metabolic diet, participants underwent hyperinsulinemic-euglycemic clamp. Serum and urine samples were collected before and during hyperinsulinemia. Change in serum magnesium, urinary magnesium to creatinine (Mg2+ :Cr) ratio, fractional excretion of urinary magnesium (FEMg2+ ), and estimated transcellular shift of magnesium were compared before and during hyperinsulinemia. RESULTS Hyperinsulinemia led to a small but statistically significant decrease in serum magnesium, and to a shift of magnesium into the intracellular compartment. Hyperinsulinemia did not significantly alter urinary magnesium to creatinine ratio or fractional excretion of urinary magnesium in the overall population, although a small but statistically significant decline in these parameters occurred in participants with diabetes. There was no significant correlation between change in fractional excretion of urinary magnesium and body mass index or insulin sensitivity measured as glucose disposal rate. CONCLUSIONS In human participants, acute hyperinsulinemia stimulates the shift of magnesium into cells with minimal alteration in renal magnesium reabsorption, except in diabetic patients who experienced a small decline in fractional excretion of urinary magnesium. The magnitude of magnesium shift into the intracellular compartment in response to insulin does not correlate with that of insulin-stimulated glucose entry into cells.
Collapse
Affiliation(s)
- Li Hao Richie Xu
- Charles & Jane Pak Center for Mineral Metabolism & Clinical Research, Dallas, TX, USA
| | - Naim M Maalouf
- Charles & Jane Pak Center for Mineral Metabolism & Clinical Research, Dallas, TX, USA
- Department of Internal Medicine, Division of Mineral Metabolism, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Endocrine Section, Medical Service, Veterans Affairs North Texas Health Care System, Dallas, TX, USA
| |
Collapse
|
19
|
Zhang C, Zhang T, Zou J, Miller CL, Gorkhali R, Yang JY, Schilmiller A, Wang S, Huang K, Brown EM, Moremen KW, Hu J, Yang JJ. Structural basis for regulation of human calcium-sensing receptor by magnesium ions and an unexpected tryptophan derivative co-agonist. SCIENCE ADVANCES 2016; 2:e1600241. [PMID: 27386547 PMCID: PMC4928972 DOI: 10.1126/sciadv.1600241] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 04/29/2016] [Indexed: 06/06/2023]
Abstract
Ca(2+)-sensing receptors (CaSRs) modulate calcium and magnesium homeostasis and many (patho)physiological processes by responding to extracellular stimuli, including divalent cations and amino acids. We report the first crystal structure of the extracellular domain (ECD) of human CaSR bound with Mg(2+) and a tryptophan derivative ligand at 2.1 Å. The structure reveals key determinants for cooperative activation by metal ions and aromatic amino acids. The unexpected tryptophan derivative was bound in the hinge region between two globular ECD subdomains, and represents a novel high-affinity co-agonist of CaSR. The dissection of structure-function relations by mutagenesis, biochemical, and functional studies provides insights into the molecular basis of human diseases arising from CaSR mutations. The data also provide a novel paradigm for understanding the mechanism of CaSR-mediated signaling that is likely shared by the other family C GPCR [G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptor] members and can facilitate the development of novel CaSR-based therapeutics.
Collapse
Affiliation(s)
- Chen Zhang
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, 50 Decatur Street, Atlanta, GA 30303, USA
| | - Tuo Zhang
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Juan Zou
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, 50 Decatur Street, Atlanta, GA 30303, USA
| | - Cassandra Lynn Miller
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, 50 Decatur Street, Atlanta, GA 30303, USA
| | - Rakshya Gorkhali
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, 50 Decatur Street, Atlanta, GA 30303, USA
| | - Jeong-Yeh Yang
- Department of Biochemistry and Molecular Biology and the Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA
| | - Anthony Schilmiller
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Shuo Wang
- Department of Biochemistry and Molecular Biology and the Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA
| | - Kenneth Huang
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, 50 Decatur Street, Atlanta, GA 30303, USA
| | - Edward M. Brown
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA
| | - Kelley W. Moremen
- Department of Biochemistry and Molecular Biology and the Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA
| | - Jian Hu
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Jenny J. Yang
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, 50 Decatur Street, Atlanta, GA 30303, USA
| |
Collapse
|
20
|
Moor MB, Bonny O. Ways of calcium reabsorption in the kidney. Am J Physiol Renal Physiol 2016; 310:F1337-50. [PMID: 27009338 DOI: 10.1152/ajprenal.00273.2015] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 03/17/2016] [Indexed: 11/22/2022] Open
Abstract
The role of the kidney in calcium homeostasis has been reshaped from a classic view in which the kidney was regulated by systemic calcitropic hormones such as vitamin D3 or parathyroid hormone to an organ actively taking part in the regulation of calcium handling. With the identification of the intrinsic renal calcium-sensing receptor feedback system, the regulation of paracellular calcium transport involving claudins, and new paracrine regulators such as klotho, the kidney has emerged as a crucial modulator not only of calciuria but also of calcium homeostasis. This review summarizes recent molecular and endocrine contributors to renal calcium handling and highlights the tight link between calcium and sodium reabsorption in the kidney.
Collapse
Affiliation(s)
- Matthias B Moor
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland; and
| | - Olivier Bonny
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland; and Service of Nephrology, Department of Medicine, Lausanne University Hospital, Lausanne, Switzerland
| |
Collapse
|
21
|
Lee CT, Ng HY, Lee YT, Lai LW, Lien YHH. The role of calbindin-D28k on renal calcium and magnesium handling during treatment with loop and thiazide diuretics. Am J Physiol Renal Physiol 2015; 310:F230-6. [PMID: 26582761 DOI: 10.1152/ajprenal.00057.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 11/16/2015] [Indexed: 12/18/2022] Open
Abstract
Calbindin-D28k (CBD-28k) is a calcium binding protein located in the distal convoluted tubule (DCT) and plays an important role in active calcium transport in the kidney. Loop and thiazide diuretics affect renal Ca and Mg handling: both cause Mg wasting, but have opposite effects on Ca excretion as loop diuretics increase, but thiazides decrease, Ca excretion. To understand the role of CBD-28k in renal Ca and Mg handling in response to diuretics treatment, we investigated renal Ca and Mg excretion and gene expression of DCT Ca and Mg transport molecules in wild-type (WT) and CBD-28k knockout (KO) mice. Mice were treated with chlorothiazide (CTZ; 50 mg · kg(-1) · day(-1)) or furosemide (FSM; 30 mg · kg(-1) · day(-1)) for 3 days. To avoid volume depletion, salt was supplemented in the drinking water. Urine Ca excretion was reduced in WT, but not in KO mice, by CTZ. FSM induced similar hypercalciuria in both groups. DCT Ca transport molecules, including transient receptor potential vanilloid 5 (TRPV5), TRPV6, and CBD-9k, were upregulated by CTZ and FSM in WT, but not in KO mice. Urine Mg excretion was increased and transient receptor potential subfamily M, member 6 (TRPM6) was upregulated by both CTZ and FSM in WT and KO mice. In conclusion, CBD-28k plays an important role in gene expression of DCT Ca, but not Mg, transport molecules, which may be related to its being a Ca, but not a Mg, intracellular sensor. The lack of upregulation of DCT Ca transport molecules by thiazides in the KO mice indicates that the DCT Ca transport system is critical for Ca conservation by thiazides.
Collapse
Affiliation(s)
- Chien-Te Lee
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Chang-Gung Memorial Hospital, Kaohsiung, Taiwan, and Chang-Gung University, College of Medicine, Taoyuan, Taiwan; Kidney Research Center, Chang Gung Memorial Hospital, Chang-Gung University, College of Medicine, Taoyuan, Taiwan
| | - Hwee-Yeong Ng
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Chang-Gung Memorial Hospital, Kaohsiung, Taiwan, and Chang-Gung University, College of Medicine, Taoyuan, Taiwan
| | - Yueh-Ting Lee
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Chang-Gung Memorial Hospital, Kaohsiung, Taiwan, and Chang-Gung University, College of Medicine, Taoyuan, Taiwan
| | - Li-Wen Lai
- Departments of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona
| | - Yeong-Hau H Lien
- Arizona Kidney Disease and Heart Center, Tucson, Arizona; and Department of Medicine, University of Arizona, Tucson, Arizona
| |
Collapse
|
22
|
Cui Y, Zhao S, Wang X, Zhou B. A novel Drosophila mitochondrial carrier protein acts as a Mg(2+) exporter in fine-tuning mitochondrial Mg(2+) homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:30-9. [PMID: 26462626 DOI: 10.1016/j.bbamcr.2015.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 10/08/2015] [Accepted: 10/09/2015] [Indexed: 12/20/2022]
Abstract
The homeostasis of magnesium (Mg(2+)), an abundant divalent cation indispensable for many biological processes including mitochondrial functions, is underexplored. In yeast, the mitochondrial Mg(2+) homeostasis is accurately controlled through the combined effects of importers, Mrs2 and Lpe10, and an exporter, Mme1. However, little is known about this Mg(2+) homeostatic process in multicellular organisms. Here, we identified the first mitochondrial Mg(2+) transporter in Drosophila, the orthologue of yeast Mme1, dMme1, by homologous comparison and functional complementation. dMme1 can mediate the exportation of mitochondrial Mg(2+) when heterologously expressed in yeast. Altering the expression of dMme1, although only resulting in about a 10% change in mitochondrial Mg(2+) levels in either direction, led to a significant survival reduction in Drosophila. Furthermore, the reduced survival resulting from dMme1 expression changes could be completely rescued by feeding the dMME1-RNAi flies Mg(2+)-restricted food or the dMME1-over-expressing flies the Mg(2+)-supplemented diet. Our studies therefore identified the first Drosophila mitochondrial Mg(2+) exporter, which is involved in the precise control of mitochondrial Mg(2+) homeostasis to ensure an optimal state for survival.
Collapse
Affiliation(s)
- Yixian Cui
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
| | - Shanke Zhao
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xudong Wang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Bing Zhou
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; Beijing Institute for Brain Disorders, Beijing, China.
| |
Collapse
|
23
|
Kamiyoshi N, Nozu K, Urahama Y, Matsunoshita N, Yamamura T, Minamikawa S, Ninchoji T, Morisada N, Nakanishi K, Kaito H, Iijima K. Pathogenesis of hypokalemia in autosomal dominant hypocalcemia type 1. Clin Exp Nephrol 2015; 20:253-7. [DOI: 10.1007/s10157-015-1160-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 08/23/2015] [Indexed: 12/27/2022]
|
24
|
Felsenfeld AJ, Levine BS, Rodriguez M. Pathophysiology of Calcium, Phosphorus, and Magnesium Dysregulation in Chronic Kidney Disease. Semin Dial 2015; 28:564-77. [DOI: 10.1111/sdi.12411] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Arnold J. Felsenfeld
- Department of Medicine; VA Greater Los Angeles Healthcare System and the David Geffen School of Medicine at UCLA; Los Angeles California
| | - Barton S. Levine
- Department of Medicine; VA Greater Los Angeles Healthcare System and the David Geffen School of Medicine at UCLA; Los Angeles California
| | - Mariano Rodriguez
- Nephrology Service; IMIBIC; Hospital Universitario Reina Sofia; University of Cordoba; Cordoba Spain
| |
Collapse
|
25
|
Excess 25-hydroxyvitamin D3 exacerbates tubulointerstitial injury in mice by modulating macrophage phenotype. Kidney Int 2015; 88:1013-29. [PMID: 26176830 DOI: 10.1038/ki.2015.210] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 04/25/2015] [Accepted: 05/14/2015] [Indexed: 12/18/2022]
Abstract
Vitamin D hydroxylated at carbon 25 (25(OH)D) is generally recognized as a precursor of active vitamin D. Despite its low affinity for the vitamin D receptor (VDR), both deficient and excessive 25(OH)D levels are associated with poor clinical outcomes. Here we studied direct effects of 25(OH)D3 on the kidney using 25(OH)D-1α-hydroxylase (CYP27B1) knockout mice. The effects of 25(OH)D3 on unilateral ureteral obstruction were analyzed as proximal tubular cells and macrophages are two major cell types that take up 25(OH)D and contribute to the pathogenesis of kidney injury. Excess 25(OH)D3 in obstructed mice worsened oxidative stress and tubulointerstitial fibrosis, whereas moderate levels of 25(OH)D3 had no effects. The exacerbating effects of excess 25(OH)D3 were abolished in CYP27B1/VDR double-knockout mice and in macrophage-depleted CYP27B1 knockout mice. Excess 25(OH)D3 upregulated both M1 marker (TNF-α) and M2 marker (TGF-β1) levels of kidney-infiltrating macrophages. In vitro analyses verified that excess 25(OH)D3 directly upregulated TNF-α and TGF-β1 in cultured macrophages but not in tubular cells. TNF-α and 25(OH)D3 cooperatively induced oxidative stress by upregulating iNOS in tubular cells. Aggravated tubulointerstitial fibrosis in mice with excess 25(OH)D3 indicated that macrophage-derived TGF-β1 also had a key role in the pathogenesis of surplus 25(OH)D3. Thus, excess 25(OH)D3 worsens tubulointerstitial injury by modulating macrophage phenotype.
Collapse
|
26
|
Blaine J, Chonchol M, Levi M. Renal control of calcium, phosphate, and magnesium homeostasis. Clin J Am Soc Nephrol 2014; 10:1257-72. [PMID: 25287933 DOI: 10.2215/cjn.09750913] [Citation(s) in RCA: 410] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Calcium, phosphate, and magnesium are multivalent cations that are important for many biologic and cellular functions. The kidneys play a central role in the homeostasis of these ions. Gastrointestinal absorption is balanced by renal excretion. When body stores of these ions decline significantly, gastrointestinal absorption, bone resorption, and renal tubular reabsorption increase to normalize their levels. Renal regulation of these ions occurs through glomerular filtration and tubular reabsorption and/or secretion and is therefore an important determinant of plasma ion concentration. Under physiologic conditions, the whole body balance of calcium, phosphate, and magnesium is maintained by fine adjustments of urinary excretion to equal the net intake. This review discusses how calcium, phosphate, and magnesium are handled by the kidneys.
Collapse
Affiliation(s)
- Judith Blaine
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Michel Chonchol
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Moshe Levi
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| |
Collapse
|
27
|
Abstract
The concept of homeostasis has been inextricably linked to the function of the kidneys for more than a century when it was recognized that the kidneys had the ability to maintain the "internal milieu" and allow organisms the "physiologic freedom" to move into varying environments and take in varying diets and fluids. Early ingenious, albeit rudimentary, experiments unlocked a wealth of secrets on the mechanisms involved in the formation of urine and renal handling of the gamut of electrolytes, as well as that of water, acid, and protein. Recent scientific advances have confirmed these prescient postulates such that the modern clinician is the beneficiary of a rich understanding of the nephron and the kidney's critical role in homeostasis down to the molecular level. This review summarizes those early achievements and provides a framework and introduction for the new CJASN series on renal physiology.
Collapse
Affiliation(s)
- Melanie P Hoenig
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Mark L Zeidel
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
28
|
Galassi A, Cozzolino M. Magnesium: a renewed player of vascular ageing in diabetic CKD patients? Clin Kidney J 2014; 7:93-6. [PMID: 25852855 PMCID: PMC4377787 DOI: 10.1093/ckj/sfu011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 02/05/2014] [Indexed: 12/24/2022] Open
Affiliation(s)
- Andrea Galassi
- Renal and Dialysis Unit, Department of Medicine , Desio Hospital , Desio , Italy
| | - Mario Cozzolino
- Department of Health Sciences, Renal Division , San Paolo Hospital, University of Milan , Milan , Italy
| |
Collapse
|
29
|
Kinoshita Y, Hori M, Taguchi M, Watanabe S, Fukumoto S. Functional activities of mutant calcium-sensing receptors determine clinical presentations in patients with autosomal dominant hypocalcemia. J Clin Endocrinol Metab 2014; 99:E363-8. [PMID: 24297799 DOI: 10.1210/jc.2013-3430] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Autosomal dominant hypocalcemia (ADH) is a congenital isolated hypoparathyroidism caused by activating mutations in the calcium-sensing receptor (CASR) gene. The clinical features of ADH are heterogeneous; some patients are asymptomatic, and others show severe hypocalcemia with Bartter's syndrome. We therefore recruited 12 patients with ADH to clarify the determinants of their clinical presentation. DESIGN AND METHODS We studied two sporadic and 10 familial cases of ADH. Serum concentrations of calcium, intact PTH, and magnesium (Mg(2+)) were measured in each patient. Fractional excretion of Mg (FE(Mg)) was calculated in spot urine samples. A nuclear factor of activated T cells luciferase assay was used to analyze the responsiveness of each mutant CaSR to extracellular Ca(2+). RESULTS Genomic analysis revealed five known activating mutations and a novel mutation, E481K, in the CASR. Patients with the A843E, C131W, or F788C mutation showed hypomagnesemia with elevated FE(Mg). Intact PTH in these patients was consistently near the detection limit. In contrast, patients with the P221L, K47N, or E481K mutation exhibited normal Mg(2+) levels. In these patients, intact PTH increased in response to low calcium, and their maximum intact PTH exceeded the lower limit of the reference range. Functional analysis showed an association between the disease severity and the in vitro activity of the mutant CaSR. CONCLUSIONS The functional activity of mutant CaSR determines the serum Mg(2+) level, renal Mg(2+) handling, and intact PTH in patients with ADH. The presence of hypomagnesemia with elevated FE(Mg) may indicate the diagnosis of ADH among patients with PTH-deficient hypoparathyroidism.
Collapse
Affiliation(s)
- Yuka Kinoshita
- Division of Nephrology and Endocrinology, Department of Medicine, University of Tokyo Hospital, Tokyo 113-8655, Japan
| | | | | | | | | |
Collapse
|
30
|
Abstract
PURPOSE OF REVIEW Regulation of calcium homeostasis during a lifetime is a complex process reflecting a balance among intestinal calcium absorption, bone calcium influx and efflux, and renal calcium excretion. Perturbations can result in hypocalcemia or hypercalcemia and adaptations in calcium handling must occur during growth and aging. RECENT FINDINGS Study of the calcium sensing receptor in the thick ascending limb of Henle and TRPV5 in the distal tubule continues to provide insights into regulation of renal calcium excretion. Hypercalcemia-induced secretion of calcitonin via activation of the calcium-sensing receptor may protect against the development of hypercalcemia. A calcilytic was shown to increase serum calcium by decreasing renal calcium excretion. Ezrin, a cross-linking protein important for renal phosphate handling, is also involved in the regulation of intestinal calcium absorption. Increased 1,25-hydroxyvitamin D (1,25D) values were shown to protect against the development of hypocalcemia by increasing calcium efflux and decreasing calcium influx in bone. Finally, fibroblast growth factor 23 stimulation, which should result in suppression of 1,25D, was shown to be prevented in a model of vitamin D deficiency in which maintenance of 1,25D is important in minimizing hypocalcemia. SUMMARY Recent information has provided new insights on how intestinal, bone and renal mechanisms are regulated to maintain calcium homeostasis.
Collapse
|
31
|
de Baaij JHF, Groot Koerkamp MJ, Lavrijsen M, van Zeeland F, Meijer H, Holstege FCP, Bindels RJM, Hoenderop JGJ. Elucidation of the distal convoluted tubule transcriptome identifies new candidate genes involved in renal Mg2+ handling. Am J Physiol Renal Physiol 2013; 305:F1563-73. [DOI: 10.1152/ajprenal.00322.2013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The kidney plays a key role in the maintenance of Mg2+ homeostasis. Specifically, the distal convoluted tubule (DCT) is instrumental in the fine-tuning of renal Mg2+ handling. In recent years, hereditary Mg2+ transport disorders have helped to identify important players in DCT Mg2+ homeostasis. Nevertheless, several proteins involved in DCT-mediated Mg2+ reabsorption remain to be discovered, and a full expression profile of this complex nephron segment may facilitate the discovery of new Mg2+-related genes. Here, we report Mg2+-sensitive expression of the DCT transcriptome. To this end, transgenic mice expressing enhanced green fluorescent protein under a DCT-specific parvalbumin promoter were subjected to Mg2+-deficient or Mg2+-enriched diets. Subsequently, the Complex Object Parametric Analyzer and Sorter allowed, for the first time, isolation of enhanced green fluorescent protein-positive DCT cells. RNA extracts thereof were analyzed by DNA microarrays comparing high versus low Mg2+ to identify Mg2+ regulatory genes. Based on statistical significance and a fold change of at least 2, 46 genes showed differential expression. Several known magnesiotropic genes, such as transient receptor potential cation channel, subfamily M, member 6 ( Trpm6), and Parvalbumin, were upregulated under low dietary Mg2+. Moreover, new genes were identified that are potentially involved in renal Mg2+ handling. To confirm that the selected candidate genes were regulated by dietary Mg2+ availability, the expression levels of solute carrier family 41, member 3 ( Slc41a3), pterin-4 α-carbinolamine dehydratase/dimerization cofactor of hepatocyte nuclear factor-1α ( Pcbd1), TBC1 domain family, member 4 ( Tbc1d4), and uromodulin ( Umod) were determined by RT-PCR analysis. Indeed, all four genes show significant upregulation in the DCT of mice fed a Mg2+-deficient diet. By elucidating the Mg2+-sensitive DCT transcriptome, new candidate genes in renal Mg2+ handling have been identified.
Collapse
Affiliation(s)
- Jeroen H. F. de Baaij
- Department of Physiology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; and
| | | | - Marla Lavrijsen
- Molecular Cancer Research, UMC Utrecht, Utrecht, The Netherlands
| | - Femke van Zeeland
- Department of Physiology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; and
| | - Hans Meijer
- Department of Physiology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; and
| | | | - René J. M. Bindels
- Department of Physiology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; and
| | - Joost G. J. Hoenderop
- Department of Physiology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; and
| |
Collapse
|
32
|
Worcester EM, Bergsland KJ, Gillen DL, Coe FL. Evidence for increased renal tubule and parathyroid gland sensitivity to serum calcium in human idiopathic hypercalciuria. Am J Physiol Renal Physiol 2013; 305:F853-60. [PMID: 23863465 DOI: 10.1152/ajprenal.00124.2013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Patients with idiopathic hypercalciuria (IH) have decreased renal calcium reabsorption, most marked in the postprandial state, but the mechanisms are unknown. We compared 29 subjects with IH and 17 normal subjects (N) each fed meals providing identical amounts of calcium. Urine and blood samples were collected fasting and after meals. Levels of three candidate signalers, serum calcium (SCa), insulin (I), and plasma parathyroid hormone (PTH), did not differ between IH and N either fasting or fed, but all changed with feeding, and the change in SCa was greater in IH than in N. Regression analysis of fractional excretion of calcium (FECa) was significant for PTH and SCa in IH but not N. With the use of multivariable analysis, Sca entered the model while PTH and I did not. To avoid internal correlation we decomposed FECa into its independent terms: adjusted urine calcium (UCa) and UFCa molarity. Analyses using adjusted Uca and unadjusted Uca parallel those using FECa, showing a dominant effect of SCa with no effect of PTH or I. The effect of SCa may be mediated via vitamin D receptor-stimulated increased abundance of basolateral Ca receptor, which is supported by the fact PTH levels also seem more responsive to serum Ca in IH than in N. Although our data support an effect of SCa on FECa and UCa, which is more marked in IH than in N, it can account for only a modest fraction of the meal effect, perhaps 10-20%, suggesting additional mediators are also responsible for the exaggerated postprandial hypercalciuria seen in IH.
Collapse
Affiliation(s)
- Elaine M Worcester
- Nephrology Section MC 5100, Univ. of Chicago Medicine, 5841 South Maryland Ave., Chicago, IL 60637.
| | | | | | | |
Collapse
|
33
|
Eckardt KU, Coresh J, Devuyst O, Johnson RJ, Köttgen A, Levey AS, Levin A. Evolving importance of kidney disease: from subspecialty to global health burden. Lancet 2013; 382:158-69. [PMID: 23727165 DOI: 10.1016/s0140-6736(13)60439-0] [Citation(s) in RCA: 770] [Impact Index Per Article: 70.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In the past decade, kidney disease diagnosed with objective measures of kidney damage and function has been recognised as a major public health burden. The population prevalence of chronic kidney disease exceeds 10%, and is more than 50% in high-risk subpopulations. Independent of age, sex, ethnic group, and comorbidity, strong, graded, and consistent associations exist between clinical prognosis and two hallmarks of chronic kidney disease: reduced glomerular filtration rate and increased urinary albumin excretion. Furthermore, an acute reduction in glomerular filtration rate is a risk factor for adverse clinical outcomes and the development and progression of chronic kidney disease. An increasing amount of evidence suggests that the kidneys are not only target organs of many diseases but also can strikingly aggravate or start systemic pathophysiological processes through their complex functions and effects on body homoeostasis. Risk of kidney disease has a notable genetic component, and identified genes have provided new insights into relevant abnormalities in renal structure and function and essential homoeostatic processes. Collaboration across general and specialised health-care professionals is needed to fully address the challenge of prevention of acute and chronic kidney disease and improve outcomes.
Collapse
Affiliation(s)
- Kai-Uwe Eckardt
- Department of Nephrology and Hypertension, University of Erlangen-Nürnberg, Erlangen, Germany.
| | | | | | | | | | | | | |
Collapse
|
34
|
Drüeke TB, Olgaard K. Report on 2012 ISN Nexus Symposium: ‘Bone and the Kidney’. Kidney Int 2013; 83:557-62. [DOI: 10.1038/ki.2012.453] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
35
|
Wolber FM, Beck KL, Conlon CA, Kruger MC. Kiwifruit and Mineral Nutrition. NUTRITIONAL BENEFITS OF KIWIFRUIT 2013; 68:233-56. [DOI: 10.1016/b978-0-12-394294-4.00013-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|