Fractionation of calcium and magnesium in equine serum.
Abstract: To establish reference values for protein-bound, ionized, and weak-acid complexed fractions of calcium and magnesium in equine serum and determine stability of ionized calcium (iCa) and ionized magnesium (iMg) in serum samples kept under various storage conditions. Methods: 28 clinically normal horses. Methods: Total calcium (tCa) and magnesium (tMg) in equine serum were fractionated by use of a micropartition system that allows separation of protein-bound calcium (pCa) and magnesium (pMg) and ultrafiltrable calcium (microCa) and magnesium (microMg) fractions. Serum concentrations of iCa and iMg were measured in the ultrafiltrate by use of selective electrodes. Serum concentration of complexed calcium (cCa) or magnesium (cMg) was calculated by subtracting iCa or iMg from microCa or microMg, respectively. Results: Mean +/-SE serum tCa concentration was 3.26 +/- 0.06 mmol/L. Calcium fractions were as follows: pCa, 1.55 +/- 0.03 mmol/L (47.4 +/- 0.9%); iCa, 1.58 +/- 0.03 mmol/L (48.5 +/- 0.7%); and cCa, 0.13 +/- 0.02 mmol/L (4.1 +/- 0.9%). Serum tMg concentration was 0.99 +/- 0.04 mmol/L. Magnesium fractions were as follows: pMg, 0.33 +/- 0.04 mmol/L (33.3 +/- 4.2%); iMg, 0.57 +/- 0.02 mmol/L (57.6 +/- 1.7%); and cMg, 0.09 +/- 0.02 mmol/L (9.1 +/- 1.9%). Refrigeration (4 degrees C) did not affect iCa values, whereas iMg declined by 8% after 120 hours. Neither iCa nor iMg was affected by freezing (-20 degrees C). Conclusions: In equine serum, iMg is less stable than iCa; thus, when serum samples are not going to be analyzed promptly, freezing may be preferable to refrigeration for storage.
Publication Date: 2006-03-02 PubMed ID: 16506908DOI: 10.2460/ajvr.67.3.463Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research conducted aimed to establish the reference values for different factions of calcium and magnesium in horse serum, and also to determine the stability of these minerals under various storage conditions.
Research Methods
In order to establish the reference values, the research followed these steps:
- 28 clinically normal horses were chosen for the study.
- The total calcium (tCa) and magnesium (tMg) in horse serum were divided into smaller fractions through a micropartition system. These fractions included protein-bound calcium (pCa) and magnesium (pMg), along with ultrafiltrable calcium (microCa) and magnesium (microMg).
- The concentrations of ionized calcium (iCa) and ionized magnesium (iMg) in the ultrafiltrate were then measured using selective electrodes.
- The concentration of complexed calcium (cCa) or complexed magnesium (cMg) was calculated by subtracting the values of ionized calcium or magnesium from the values of ultrafiltrable calcium or magnesium, respectively.
Research Results
The average serum total calcium concentration was found to be 3.26 +/- 0.06 mmol/L, with calcium fractions being:
- pCa at 1.55 +/- 0.03 mmol/L (47.4 +/- 0.9%),
- iCa at 1.58 +/- 0.03 mmol/L (48.5 +/- 0.7%), and
- cCa at 0.13 +/- 0.02 mmol/L (4.1 +/- 0.9%).
The total magnesium concentration in serum was found to be 0.99 +/- 0.04 mmol/L, with magnesium fractions being:
- pMg at 0.33 +/- 0.04 mmol/L (33.3 +/- 4.2%),
- iMg at 0.57 +/- 0.02 mmol/L (57.6 +/- 1.7%), and
- cMg at 0.09 +/- 0.02 mmol/L (9.1 +/- 1.9%).
Findings on Stability of Serum
The study also found that refrigeration at 4 degrees Celsius did not affect iCa values. However, iMg declined by about 8% after 120 hours. Neither iCa nor iMg was affected by freezing at -20 degrees Celsius. Thus, if serum samples are not going to be promptly analyzed, it would be better to store them in freezing conditions rather than refrigerating. This is especially relevant because ionized magnesium is less stable than ionized calcium in horse serum.
Cite This Article
APA
Lopez I, Estepa JC, Mendoza FJ, Mayer-Valor R, Aguilera-Tejero E.
(2006).
Fractionation of calcium and magnesium in equine serum.
Am J Vet Res, 67(3), 463-466.
https://doi.org/10.2460/ajvr.67.3.463 Publication
Researcher Affiliations
- Department of Medicina y Cirugia Animal, Universidad de Cordoba, Campus Universitario Rabanales, Ctra Madrid-Cadiz km 396, 14014 Cordoba, Spain.
MeSH Terms
- Animals
- Calcium / blood
- Female
- Horses / blood
- Magnesium / blood
- Male
- Reference Values
- Ultrafiltration / veterinary
Citations
This article has been cited 2 times.- Sanmartí J, Armengou L, Troya-Portillo L, Robles-Guirado JÁ, Bassols A, Ríos J, Jose-Cunilleras E. Plasma-Ionized Magnesium in Hospitalized Horses with Gastrointestinal Disorders and Systemic Inflammatory Response Syndrome. Animals (Basel) 2022 Jun 7;12(12).
- Satué K, Fazio E, Medica P, Velasco-Martinez MG, Cravana C, Bruschetta G, La Fauci D. The Pivotal Interaction Between Serotonin and Calcium Shifts in Lactating Pregnant Spanish Purebred Mares: The Aging Effect. Vet Sci 2025 Apr 23;12(5).
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
