Source Paper
Hyponatremia-induced osteoporosis
Joseph G Verbalis, Julianna Barsony, Yoshihisa Sugimura, Ying Tian, et al.
Source Paper
Joseph G Verbalis, Julianna Barsony, Yoshihisa Sugimura, Ying Tian, et al.
Journal of Bone and Mineral Research • 2009
Abstract There is a high prevalence of chronic hyponatremia in the elderly, frequently owing to the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Recent reports have shown that even mild hyponatremia is associated with impaired gait stability and increased falls. An increased risk of falls among elderly hyponatremic patients represents a risk factor for fractures, which would be further amplified if hyponatremia also contributed metabolically to bone loss. To evaluate this possibility, we studied a rat model of SIADH and analyzed data from the Third National Health and Nutrition Examination Survey (NHANES III). In rats, dual-energy X-ray absorptiometry (DXA) analysis of excised femurs established that hyponatremia for 3 months significantly reduced bone mineral density by approximately 30% compared with normonatremic control rats. Moreover, micro-computed tomography (µCT) and histomorphometric analyses indicated that hyponatremia markedly reduced both trabecular and cortical bone via increased bone resorption and decreased bone formation. Analysis of data from adults in NHANES III by linear regression models showed that mild hyponatremia is associated with increased odds of osteoporosis (T-score –2.5 or less) at the hip [odds ratio (OR) = 2.85; 95% confidence interval (CI) 1.03–7.86; p <.01]; all models were adjusted for age, sex, race, body mass index (BMI), physical activity, history of diuretic use, history of smoking, and serum 25-hydroxyvitamin D [25(OH)D] levels. Our results represent the first demonstration that chronic hyponatremia causes a substantial reduction of bone mass. Cross-sectional human data showing that hyponatremia is associated with significantly increased odds of osteoporosis are consistent with the experimental data in rodents. Our combined results suggest that bone quality should be assessed in all patients with chronic hyponatremia. © 2010 American Society for Bone and Mineral Research.
Objective: To induce chronic hyponatremia in rats via DDAVP infusion and liquid diet, with controls receiving either solid diet or liquid diet without DDAVP, and to assess effects with additional vitamin D3 supplementation in selected groups
This is a Chronic Hyponatremia Model - Experiment 2 protocol using rat as the model organism. The procedure involves 10 procedural steps, 3 equipment items, 5 materials. Extracted from a 2009 paper published in Journal of Bone and Mineral Research.
Model and subjects
rat • Sprague-Dawley • male • 6 weeks old • 250 to 300 g • 6
Study window
~6 week study window | ~24 hours hands-on
Core workflow
Animal acquisition and baseline measurements • Osmotic minipump implantation • Diet assignment and feeding
Primary readouts
Key equipment and reagents
Verified items
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Obtain male albino Sprague-Dawley rats at 6 weeks old, weighing 250-300g. Measure baseline body weight.
Note: Six rats per group in experiment 2
“male albino Sprague-Dawley rats (6 weeks old, 250 to 300 g; Taconic Farms, Germantown, NY, USA)”
Surgically implant Alzet Model 2004 osmotic minipump subcutaneously for continuous DDAVP infusion at 5 ng/h in hyponatremic groups
Note: Minipumps replaced monthly to maintain constant desmopressin levels
“infused with desmopressin (DDAVP, Aventis, Bridgewater, NJ, USA) at a rate of 5 ng/h via a subcutaneously implanted osmotic minipump (Alzet Model 2004; Durect Co., Cupertino, CA, USA)”
Assign rats to experimental groups: Group 1 (hyponatremic) receives DDAVP and 70 mL/d liquid diet (F1268SP); Group 2 (control) receives solid AIN-76 diet without DDAVP; Group 3 (control) receives liquid diet without DDAVP. Administer liquid diet via feeding tubes (No. 9010, BioServ).
Note: Liquid diet supplied 30 IU/d vitamin D3 and 155 mg/d calcium at 1.0 kcal/mL caloric density
“fed 70 mL/d of a nutritionally balanced rodent liquid formula (F1268SP, BioServ, Frenchtown, NJ, USA) at a caloric density of 1.0 kcal/mL”
Administer biweekly intramuscular injections of 50,000 U/kg vitamin D3 to hyponatremic group and solid diet control group
Note: Vitamin D3 from GeroVitamins, Zalmoxian Products
“Rats in one of the hyponatremic groups and rats on the solid AIN-76 diet in experiment 2 also received biweekly intramuscular injections of 50,000 U/kg vitamin D 3”
Measure body weight biweekly throughout the 3-month experimental period
“Body weight was measured biweekly”
Replace osmotic minipumps monthly to maintain constant desmopressin levels
“The osmotic minipumps were replaced monthly to maintain constant desmopressin levels”
Monitor serum or plasma sodium levels monthly to verify hyponatremia induction and stability
Note: Sodium levels remained stable over the duration of the 3 month experiments
“Serum or plasma sodium levels were monitored monthly and remained stable over the duration of the 3 month experiments”
House rats intermittently in Nalgene metabolic cages (No. 650-0100) for 24-hour urine collections at the end of each month
Note: Urine collected both with and without preservative
“Rats were housed intermittently in metabolic cages (No. 650-0100, Nalgene) for 24 hour urine collections”
Collect 2 mL survival blood by tail vein venipuncture under inhalation anesthesia with isoflurane (3% in oxygen at 0.5 L/min)
Note: Performed at end of 3-month experiment
“Survival blood (2 mL) was collected by tail vein venipuncture under inhalation anesthesia with isoflurane (3% in oxygen at 0.5 L/min)”
Collect nonsurvival blood by cardiac puncture under isoflurane anesthesia. Increase isoflurane dose until lack of heart contraction and respiration indicates death.
Note: Performed at end of 3-month experiment
“Nonsurvival blood was collected by cardiac puncture, also under isoflurane anesthesia; after blood collection, isoflurane dose was increased until the lack of heart contraction and respiration indicated death”
This section explains what the experiment is doing, which readouts matter, what the data artifacts usually look like, and how the analysis should flow from raw capture to reported result.
To induce chronic hyponatremia in rats via DDAVP infusion and liquid diet, with controls receiving either solid diet or liquid diet without DDAVP, and to assess effects with additional vitamin D3 supplementation in selected groups
Objective
To induce chronic hyponatremia in rats via DDAVP infusion and liquid diet, with controls receiving either solid diet or liquid diet without DDAVP, and to assess effects with additional vitamin D3 supplementation in selected groups
Subjects
From paperrat • Sprague-Dawley • male • 6 weeks old • 250 to 300 g
Sample count
From paper6
Cohort notes
From paperalbino; six rats per group in experiment 2
Animal acquisition and baseline measurements
Osmotic minipump implantation
Diet assignment and feeding (3 months)
Vitamin D3 supplementation (Biweekly for 3 months)
Serum or plasma sodium levels
From paperNot explicitly mentioned in the methods section
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Body weight
From paperNot explicitly mentioned in the methods section
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
24-hour urine output and composition
From paperNot explicitly mentioned in the methods section
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Blood samples for analysis
From paperNot explicitly mentioned in the methods section
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Serum or plasma sodium levels
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Body weight
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
24-hour urine output and composition
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Blood samples for analysis
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Acquisition
Collect raw experimental outputs with enough metadata to preserve sample identity, condition, and timing.
Preprocessing / cleaning
Not explicitly mentioned in the methods section
Scoring or quantification
Quantify the primary readouts for this experiment: Serum or plasma sodium levels; Body weight; 24-hour urine output and composition; Blood samples for analysis.
Statistical comparison
Statistical method not yet structured for this page.
Reporting output
Report representative outputs alongside summary comparisons for Serum or plasma sodium levels, Body weight, 24-hour urine output and composition, Blood samples for analysis.
Source links and direct wording from the methods section for validation and deeper review.
Citation
Joseph G Verbalis et al. (2009). Hyponatremia-induced osteoporosis. Journal of Bone and Mineral Research
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Gather these items before starting the experiment. Check off items as you prepare.
Durect Co. • Alzet Model 2004
BioServ • No. 9010
Nalgene • No. 650-0100
Aventis
BioServ • F1268SP
GeroVitamins, Zalmoxian Products
1 item with ReplicateScience direct pages
Estimated: $9,900.00
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