TY - JOUR
T1 - In vitro effects of reactive oxygen metabolites, with and without flunixin meglumine, on equine colonic mucosa
AU - Inoue, Olivia J.
AU - Freeman, David E.
AU - Wallig, Matthew A.
AU - Clarkson, Robert B.
PY - 2007/3
Y1 - 2007/3
N2 - Objective - To determine effects of reactive oxygen metabolites (ROMs), with and without flunixin meglumine, on equine right ventral colon (RVC) in vitro. Animals - 18 healthy horses and ponies. Procedures - In 3 groups of 6 animals each, short-circuit current and conductance were measured in RVC mucosa in Ussing chambers. The 3 groups received physiologic saline (0.9% NaCl) solution, IV, 10 minutes before euthanasia and tissue incubation in Krebs-Ringer-bicarbonate (KRB) solution; flunixin meglumine (1.1 mg/kg, IV) 10 minutes before euthanasia and tissue incubation in KRB solution; or physiologic saline solution, IV, 10 minutes before euthanasia and incubation in KRB solution with 2.7 × 105M flunixin meglumine. Incubation conditions included control (no addition) and ROM systems, including addition of 1mM xanthine and 80 mU of xanthine oxidase (to produce the superoxide radical), 1mM H2O2, and 1mM H2O2 and 0.5mM ferrous sulfate (to produce the hydroxyl radical). Results - All ROMs that were added or generated significantly increased the short-circuit current except in tissues coincubated with flunixin meglumine, and they induced mild epithelial vacuolation and apoptosis, but did not disrupt the epithelium nor change conductance, lactate dehydrogenase release, or [3H]mannitol flux. Conclusions and Clinical Relevance - Responses to ROMs could be attributed to increased chloride secretion and inhibited neutral NaCl absorption in equine RVC, possibly by stimulating prostaglandin production. The ROMs examined under conditions of this study could play a role in prostaglandin-mediated colonic secretion in horses with enterocolitis without causing direct mucosal injury.
AB - Objective - To determine effects of reactive oxygen metabolites (ROMs), with and without flunixin meglumine, on equine right ventral colon (RVC) in vitro. Animals - 18 healthy horses and ponies. Procedures - In 3 groups of 6 animals each, short-circuit current and conductance were measured in RVC mucosa in Ussing chambers. The 3 groups received physiologic saline (0.9% NaCl) solution, IV, 10 minutes before euthanasia and tissue incubation in Krebs-Ringer-bicarbonate (KRB) solution; flunixin meglumine (1.1 mg/kg, IV) 10 minutes before euthanasia and tissue incubation in KRB solution; or physiologic saline solution, IV, 10 minutes before euthanasia and incubation in KRB solution with 2.7 × 105M flunixin meglumine. Incubation conditions included control (no addition) and ROM systems, including addition of 1mM xanthine and 80 mU of xanthine oxidase (to produce the superoxide radical), 1mM H2O2, and 1mM H2O2 and 0.5mM ferrous sulfate (to produce the hydroxyl radical). Results - All ROMs that were added or generated significantly increased the short-circuit current except in tissues coincubated with flunixin meglumine, and they induced mild epithelial vacuolation and apoptosis, but did not disrupt the epithelium nor change conductance, lactate dehydrogenase release, or [3H]mannitol flux. Conclusions and Clinical Relevance - Responses to ROMs could be attributed to increased chloride secretion and inhibited neutral NaCl absorption in equine RVC, possibly by stimulating prostaglandin production. The ROMs examined under conditions of this study could play a role in prostaglandin-mediated colonic secretion in horses with enterocolitis without causing direct mucosal injury.
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U2 - 10.2460/ajvr.68.3.305
DO - 10.2460/ajvr.68.3.305
M3 - Article
C2 - 17331021
AN - SCOPUS:33947643161
SN - 0002-9645
VL - 68
SP - 305
EP - 312
JO - American journal of veterinary research
JF - American journal of veterinary research
IS - 3
ER -