title: Temporal effects of freezing on plasma nitric oxide concentrations in ponies.
abstract: The purpose of this study was to compare concentrations of nitric oxide (NO) in fresh plasma versus frozen plasma, and determine the temporal effects of freezing on jugular venous plasma NO concentrations in clinically healthy ponies. Twenty-eight helminth-naive ponies, aged from 4 to 6 mo, were raised and maintained under parasite-free conditions. Blood was collected from the jugular vein, centrifuged, and the plasma supernatant was analyzed fresh for NO concentrations using a chemiluminescent method. The remaining samples were aliquoted into 12 samples and stored at -70 degrees C until they were analyzed for NO concentration. Plasma NO concentration was measured at monthly intervals for 12 mo. There were significant differences in the plasma NO concentration across time compared with the baseline value at 1, 3, 4, 6, 7, and 11 mo. However, these values remained within the range for clinically healthy equids compared with concentrations of NO from horses with increased NO from diseased states.
authors.affiliation: Equine Studies Health Program, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana 70803-8410, USA. jhubert@vetmed.lsu.edu
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Hubert
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Seahorn
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Klei
authors.forename: Giselle
authors.initials: G
authors.lastname: Hosgood
authors.forename: Rustin M
authors.initials: RM
authors.lastname: Moore
mesh_terms: D000818:Animals; D001793:Blood Preservation / Q000379:methods / Q000592:standards / Q000662:veterinary*; D005260:Female; D005615:Freezing; D006734:Horse Diseases / Q000097:blood*; D006736:Horses / Q000097:blood*; D008297:Male; D009569:Nitric Oxide / Q000097:blood*; D013048:Specimen Handling / Q000379:methods / Q000662:veterinary; D013997:Time Factors
chemical_list: D009569:Nitric Oxide