title: Quantification and comparison of baseline cortisol levels between aqueous and plasma from healthy anesthetized hound dogs utilizing mass spectrometry.
abstract: OBJECTIVE
  The purpose of this study is to quantify and compare the resting cortisol levels between aqueous (Aq) and plasma of anesthetized hound dogs utilizing mass spectrometry.
  
  
  METHODS
  Nine hound breed dogs weighing between 20.8 and 29.2 kg (x = 26.3 kg, SD ± 2.6 kg) were utilized from a previous project.
  
  
  METHODS
  All dogs underwent two anesthesia sessions to harvest Aq from each eye respectively. A paired blood sample was taken immediately after aqueous centesis. The Aq and plasma were analyzed for cortisol levels using mass spectrometry. Correlation of cortisol levels in dog serum and ocular fluid was determined with Sigma Stat using Pearson's correlation analysis. The level of significance for correlation analysis was set at P < 0.05.
  
  
  RESULTS
  The plasma resting cortisol levels in the dog ranged from 3.59 to 89.35 nm (x = 31.68 nm, SD ± 28.53 nm), while the Aq cortisol levels ranged from 0.82 to 5.62 nm (x = 2.73 nm, SD ± 1.94 nm). The correlation of cortisol levels in Aq compared to plasma was significant (P = 0.008) with a correlation coefficient of r = 0.779. Based on these results, 61% (r = 0.779(2) ) of the variation in Aq cortisol levels is explained by the variations in plasma cortisol levels.
  
  
  CONCLUSIONS
  This study identified significant levels of cortisol in the Aq of the canine eye and positively correlated them with plasma cortisol levels. The dog may offer a representative model for further studies to help clarify the overall role of cortisol in the anterior chamber.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, 39762, USA.
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Claude
authors.forename: William W
authors.initials: WW
authors.lastname: Miller
authors.forename: Anne M
authors.initials: AM
authors.lastname: Beyer
authors.forename: Kenneth O
authors.initials: KO
authors.lastname: Willeford
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Ross
mesh_terms: D000818:Animals; D001082:Aqueous Humor / Q000737:chemistry*; D004285:Dogs / Q000097:blood* / Q000378:metabolism; D006854:Hydrocortisone / Q000097:blood* / Q000737:chemistry*; D013058:Mass Spectrometry / Q000662:veterinary*; D015394:Molecular Structure; D012016:Reference Values
chemical_list: D006854:Hydrocortisone
keywords: aqueous; canine; cortisol; mass spectrometry; ocular