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Brain expression of inducible cyclooxygenase 2 messenger RNA in rats undergoing cardiopulmonary bypass
Journal article   Open access   Peer reviewed

Brain expression of inducible cyclooxygenase 2 messenger RNA in rats undergoing cardiopulmonary bypass

B J Hindman, S A Moore, J Cutkomp, T Smith, S E Ross-Barta, F Dexter and J E Brian Jr
Anesthesiology, Vol.95(6), pp.1380-1388
12/2001
DOI: 10.1097/00000542-200112000-00017
PMID: 11748396
url
https://doi.org/10.1097/00000542-200112000-00017View
Published (Version of record) Open Access

Abstract

We hypothesized that systemic proinflammatory cytokines or endotoxemia, or both, associated with cardiopulmonary bypass (CPB) would increase expression of inducible cyclooxygenase (COX-2) or inducible nitric oxide synthase (iNOS) messenger RNA (mRNA), or both, in brain. Isoflurane-anesthetized Sprague-Dawley rats were randomly selected for CPB (n = 6) or sham surgery (n = 6). All animals underwent tracheotomy and controlled ventilation, arterial and venous pressure monitoring, insertion of a jugular venous outflow catheter, insertion of a subclavian arterial inflow catheter, systemic anticoagulation (500 U/kg heparin) and, except during CPB, servoregulation of pericranial temperature at 37.5 degrees C. Animals selected for CPB underwent 1 h of CPB at 165 ml x kg(-1) x min(-1) (31.8 +/- 0.2 degrees C), whereas animals having sham surgery underwent no intervention during this interval. Thereafter, all animals were given protamine and remained anesthetized for 4 more h. Brain and liver COX-2 and iNOS mRNA expression were determined by a ribonuclease protection assay with ribosomal L32 mRNA as a loading control. Arterial blood was analyzed for interleukin 1beta, interleukin 6, and endotoxin concentrations. Endotoxin concentrations did not increase above baseline values in either group. At 4 h after the CPB interval, interleukin 6 concentrations were significantly greater in CPB animals (101 +/- 45 pg/ml) versus sham animals (44 +/- 17 pg/ml) (P = 0.025). Brain COX-2 expression was significantly greater in CPB animals (0.36 +/- 0.11) versus shams (0.19 +/- 0.08) (P = 0.013). Brain COX-2 expression correlated with interleukin 6 concentration 4 h after CPB (r = 0.91; P = 5 x 10(-5)). In brain, iNOS mRNA was not detected in any animal. Cardiopulmonary bypass animals had only trace COX-2 and iNOS mRNA induction in liver. Cardiopulmonary bypass was associated with increased systemic interleukin 6 concentrations and increased brain COX-2 expression.
Anesthetics, Inhalation Prostaglandin-Endoperoxide Synthases - biosynthesis Gene Expression Regulation, Enzymologic - drug effects Liver - enzymology Cytokines - metabolism Cyclooxygenase 2 Brain - enzymology Enzyme Induction Rats Electron Transport Complex IV - biosynthesis Male Cardiopulmonary Bypass Nitric Oxide Synthase Type II Rats, Sprague-Dawley Isoflurane RNA, Messenger - biosynthesis Animals Nuclease Protection Assays Nitric Oxide Synthase - biosynthesis Isoenzymes - biosynthesis Endotoxins - pharmacology Anesthesia, Inhalation

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