Protamine and Acute Depletion of Magnesium Limit Bone Response to Parathyroid Hormone
| Autor: | Berkley Brandt, Dana G. Briggs, Kevin G. Ragosta, William H Bergstrom |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Adult
medicine.medical_specialty Parathyroid hormone chemistry.chemical_element Calcium Bone and Bones Internal medicine medicine Animals Homeostasis Humans Protamines Child Receptor Calcium metabolism Cardiopulmonary Bypass biology business.industry Metabolic disorder Osteoblast medicine.disease Protamine Stimulation Chemical Rats medicine.anatomical_structure Endocrinology Anesthesiology and Pain Medicine chemistry Parathyroid Hormone biology.protein business Magnesium Deficiency |
| Zdroj: | Anesthesia & Analgesia. 82:29-32 |
| ISSN: | 0003-2999 |
| DOI: | 10.1213/00000539-199601000-00006 |
| Popis: | The effect of protamine on calcium homeostasis was studied in nine pediatric patients undergoing cardiopulmonary bypass. Total serum calcium decreased from 8.44 mg/dL to 7.49 mg/dL (P < 0.05) after protamine. Ionized calcium decreased from 1.39 to 1.31 mmol/L (P < 0.05). A bioassay determined the etiology of this response. Bone disks were placed in sera, protamine, parathyroid hormone, parathyroid hormone antibody, or magnesium-depleted solutions, then were incubated in solutions with known calcium content. The change in the media's calcium concentration reflects the bone's response to the initial stimulus. Calcium change is expressed as Experimental delta/Control delta (E/C). Normal bone responds to parathyroid hormone, E/C = 0.59 (P < 0.001). Protamine-treated bone loses this response, E/C = 0.9 (P = not significant [NS]). A parathyroid-hormone-induced osteoblast messenger was found. Protamine-treated bone continued to respond to this messenger, E/C = 0.42 (P < 0.001). Bone showed reversible loss of response to parathyroid hormone after incubation in magnesium-free solution, E/C = 0.93 (P = NS). With reincubation in magnesium, E/C = 0.69 (P < 0.01). Since protamine blocks parathyroid receptors, and magnesium depletion limits the bone's response to parathyroid hormone, this may explain the persistent hypocalcemia seen in some patients undergoing cardiopulmonary bypass. |
| Databáze: | OpenAIRE |
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