Effect of intravenous administration of hydroxyethyl-starch-deferoxamine on oxygen-derived free radical generation in cancellous bone specimens obtained from dogs.
The ability of IV administered hydroxyethyl-starch-deferoxamine to attenuate radical production in freshly procured cancellous bone specimens was investigated, using spin-trapping and electron spin resonance (ESR) techniques. A core cancellous bone specimen 10 mm long and 5.6 mm in diameter was obtained, using aseptic technique, from the proximal portion of the humerus of 30 adult mixed-breed dogs. After procurement of the initial bone specimen, 10 dogs received a 10% solution of hydroxyethyl-starch-deferoxamine in 0.9% NaCl (50 mg/kg of body weight, IV), 10 dogs received an equivalent volume (5 ml/kg, IV) of a 10% solution of hydroxyethyl-starch in 0.9% NaCl, and 10 dogs received 0.9% saline solution (5 ml/kg, IV). A second core cancellous bone specimen was obtained from the contralateral humerus of each dog 45 minutes after treatment. All specimens were individually incubated in the spin trap alpha-phenyl-N-tert-butylnitrone in Eagle's minimum essential medium, at 26 C for 45 minutes, then were frozen at -20 C until they were prepared for analysis by ESR spectroscopy. Each specimen was thawed, homogenized, and extracted in a low-dielectric organic solvent prior to obtaining an ESR spectrum, which was analyzed for hyperfine splitting constants for radical identification. Each first-derivative spectrum was digitally double-integrated to obtain an area; these areas were used to compare intensities of the spin adducts. Difference in the area obtained before and after treatment for each dog was expressed as a ratio of that dog's pretreatment area ([pretreatment - posttreatment])/pretreatment).(ABSTRACT TRUNCATED AT 250 WORDS)
Lewis
D D
DD
Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge 70803.
Church
D F
DF
Hosgood
G
G
D000818:Animals; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism*; D003676:Deferoxamine / Q000008:administration & dosage / Q000494:pharmacology*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005609:Free Radicals / Q000378:metabolism; D006895:Hydroxyethyl Starch Derivatives / Q000008:administration & dosage / Q000494:pharmacology*; D007262:Infusions, Intravenous; D012016:Reference Values; D013481:Superoxides / Q000378:metabolism*
D005609:Free Radicals; D006895:Hydroxyethyl Starch Derivatives; C068460:hydroxyethyl starch-deferoxamine conjugate; D013481:Superoxides; D003676:Deferoxamine