Open AccessAlterations in Serum Parathyroid Hormone and Electrolyte Concentrations and Urinary Excretion of Electrolytes in Horses with Induced Endotoxemia
Author(s) -
Toribio Ramiro E.,
Kohn Catherine W.,
Hardy Joanne,
Rosol Thomas J.
Publication year - 2005
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/j.1939-1676.2005.tb02686.x
Subject(s) - hypomagnesemia , medicine , endocrinology , parathyroid hormone , sodium , excretion , calcium , calcium metabolism , sepsis , magnesium , chemistry , organic chemistry
Hypocalcemia and hypomagnesemia are common in horses with sepsis and endotoxemia. We hypothesize that endotoxemia triggers a systemic inflammatory response that results in hypocalcemia and hypomagnesemia. The goal of this study was to determine the effect of endotoxin (lipopolysaccharide [LPS]) administration to healthy horses on serum parathyroid hormone (PTH), ionized calcium (Ca2+) and total calcium (tCa), ionized magnesium (Mg 2+ ) and total magnesium (tMg), phosphate (Pi), potassium (K+), sodium (Na+), chloride (Cl ‐ ), and insulin concentrations, and on the urinary excretion of these electrolytes. Twelve mares were infused with Escherichia coli LPS (30 ng/kg/h IV) for 1 hour. Six mares were infused with saline (controls). In LPS‐infused horses, heart rate increased significantly from (mean ± SD) 40.0 ± 1.3 to 70.0 ± 9.0 beats/min, respiratory rate from 12.7 ± 1.0 to 21.1 ± 3.0 breaths/min, body temperature from 37.4 ± 0.3 to 38.9 ± 0.6°C, and tumor necrosis factor‐α concentrations from 6.6 ± 3.5 to 507 ± 260 pg/mL ( P < .05). White blood cell count decreased significantly from 7,570 ± 600 to 1,960 ± 560 cells/μL. Serum concentrations of Ca 2+ decreased from 6.5 ± 0.3 to 6.0 ± 0.3 mg/dL, of Mg 2+ from 0.53 ± 0.06 to 0.43 ± 0.04 mM, of tMg from 0.78 ± 0.05 to 0.62 ± 0.08 mM, of K+ from 4.3 ± 0.4 to 3.0 ± 0.5 mEq/L, and of Pi from 3.4 ± 0.5 to 1.7 ± 0.5 mg/dL (all P < .05). PTH increased significantly from 1.3 ± 0.4 to 6.0 ± 5.2 pM; however, in some horses (n = 2), PTH did not increase despite hypocalcemia. Insulin increased significantly from 9.4 ± 3.6 to 50.5 ± 9.6 μIU/mL (n = 3). Urinary fractional excretion of Ca 2+ decreased significantly from 4.7 ± 1.4 to 1.7 ± 1.2%, of Mg 2+ from 36.6 ± 6.5 to 11.7 ± 7.3%, and of K+ from 37.9 ± 11.3 to 17.7 ± 6.2%. Fractional excretion of Pi increased from 0.02 ± 0.02 to 0.14 ± 0.07% and of Na+ from 0.26 ± 0.13% to 1.2 ± 0.5%. No changes were found in serum tCa, Na+, and Cl ‐ concentrations. In conclusion, endotoxemia in horses resulted in electrolyte abnormalities that included hypocalcemia, hypomagnesemia, hypokalemia, hypophosphatemia, and increased serum PTH and insulin concentrations.