Effects of ketamine/xylazine on expression of tumor necrosis factor-alpha, inducible nitric oxide synthase, and cyclo-oxygenase-2 in rat gastric mucosa during endotoxemia.

Kenneth S. Helmer, Yan Cui, Lily Chang, Ashvin Dewan, David W. Mercer

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38 Scopus citations


Some anesthetics attenuate expression of endotoxin-induced production of proinflammatory genes. The anesthetic combination of ketamine/xylazine (K/X) decreases lipopolysaccharide (LPS)-induced liver injury in rats. However, the effects of K/X on gut function and gene expression are unknown. The purpose of this study was to examine the effect of K/X on LPS-induced gastric fluid accumulation, and gastric tumor necrosis factor (TNF)-alpha, inducible nitric oxide synthase (iNOS), and cyclo-oxygenase (COX)-2 expression, as well as serum TNF-alpha protein levels over time. We hypothesized that K/X would attenuate these LPS-induced endpoints. Rats were given either intraperitoneal saline or K (70 mg/kg) and X (6 mg/kg) 1 h before saline or LPS (20 mg/kg i.p.) treatment of 1, 3, or 5 h. Serum and gastric fluid and mucosa were collected and TNF-alpha, iNOS, and COX-2 expression were determined. LPS caused a significant increase in early serum and gastric mucosal TNF-alpha protein expression at 1 h, an effect that was significantly attenuated by K/X pretreatment. LPS caused significant gastric stasis and increased iNOS and COX-2 mRNA expression and iNOS protein expression in the stomach when compared with controls. K/X attenuated LPS-induced gastric fluid accumulation and upregulation of iNOS mRNA and protein, but not COX-2. These data indicate that K/X inhibits some proinflammatory genes and pathophysiologic responses in the serum and stomach during endotoxemia. The effects of K/X appear to inhibit transcriptional events in iNOS expression, which may be dependent on K/X-induced inhibition of early TNF-alpha expression. Furthermore, in rat models of endotoxemia, especially those evaluating the stomach, careful consideration needs to be given if anesthetic combinations with ketamine and/or xylazine are used, as they alter LPS-induced responses.

Original languageEnglish (US)
Pages (from-to)63-69
Number of pages7
JournalShock (Augusta, Ga.)
Issue number1
Publication statusPublished - Jul 2003


ASJC Scopus subject areas

  • Emergency Medicine
  • Critical Care and Intensive Care Medicine

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