title: Serum concentrations of calcium, phosphorus, magnesium and calciotropic hormones in donkeys.
abstract: OBJECTIVE
  To provide reference values for serum biochemical variables that are used for evaluation of mineral metabolism in donkeys and compare values with those in horses.
  
  
  METHODS
  18 donkeys and 18 horses.
  
  
  METHODS
  Total calcium (tCa), total magnesium (tMg), and inorganic phosphorus (P) concentrations were measured in serum samples via spectrophotometry. Ionized calcium (iCa) and magnesium (iMg) concentrations were quantified with selective electrodes. By use of a micropartition system, tCa and tMg were fractionated to separate protein-bound (pCa, pMg) and ultrafiltrable fractions. Complexed calcium (cCa) and magnesium (cMg) concentrations were calculated by substracting ionized fractions from ultrafiltrable fractions. Parathyroid hormone (PTH) and calcitriol (CTR) concentrations were measured via radioimmunoassay.
  
  
  RESULTS
  Serum tCa concentration in donkeys (3.37 +/- 0.21 mmol/L) was composed of pCa (1.59 +/- 0.21 mmol/L [47.0 +/- 4.2%]), iCa (1.69 +/- 0.04 mmol/L [50.4 +/- 3.0%]), and cCa (0.09 +/- 0.08 mmol/L [2.6 +/- 2.9%]). Serum tMg concentration (1.00 +/- 0.08 mmol/L) was fractioned in pMg (0.23 +/- 0.08 mmol/L [23.4 +/- 8.1%]), iMg (0.59 +/- 0.04 mmol/L [58.8 +/- 5.1%]), and cMg (0.18 +/- 0.08 mmol/L [17.8 +/- 7.2%]). Serum concentrations of P (1.14 +/- 0.30 mmol/L), PTH (20.4 +/- 21.2 pg/mL), and CTR (13.4 +/- 5.9 pg/mL) were determined.
  
  
  CONCLUSIONS
  Serum variables of mineral metabolism in donkeys were within reference ranges for horses. However, when compared with horses, donkeys had higher iCa, cMg, and CTR and lower pMg and PTH concentrations.
authors.affiliation: Department of Medicina y Cirugia Animal, Universidad de Cordoba, Campus Universitario Rabanales, Ctra Madrid-Cadiz km 396, 14014 Cordoba, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Lopez
authors.forename: Jose C
authors.initials: JC
authors.lastname: Estepa
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Mendoza
authors.forename: Mariano
authors.initials: M
authors.lastname: Rodriguez
authors.forename: Escolastico
authors.initials: E
authors.lastname: Aguilera-Tejero
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000097:blood*; D018397:Equidae / Q000097:blood*; D006736:Horses / Q000097:blood; D008274:Magnesium / Q000097:blood*; D010281:Parathyroid Hormone / Q000097:blood*; D010758:Phosphorus / Q000097:blood*
chemical_list: D010281:Parathyroid Hormone; D010758:Phosphorus; D002117:Calcitriol; D008274:Magnesium; D002118:Calcium