Urethane suppresses rat lung inducible cyclooxygenase and nitric oxide synthase mRNA levels

Abstract.

Objective and Design: The purpose of the present study was to evaluate the effect of urethane, pentobarbital sodium and ketamine-xylazine anesthesia upon constitutive and inducible cyclooxygenase (COX-1; COX-2) and nitric oxide synthase (eNOS; iNOS) mRNA levels in the lung.¶Methods: mRNA levels were determined by the semiquantitative RT-PCR technique.¶Treatment: Urethane (1.1g/kg ip), Pentobarbital Sodium (40 mg/kg ip), and ketamine (85 mg/kg) - xylazine (15 mg/ kg, im). Non-anesthetized animals served as controls.¶Material: Sprague-Dawley rat lungs¶Results: Urethane significantly decreased COX-1 and COX-2 mRNA levels to 30% of control values. This agent had no effect upon eNOS, but completely suppressed iNOS mRNA levels. Pentobarbital sodium and ketamine had no effect on the mRNA levels for COX-1 and COX-2 the lung.¶Conclusions: Urethane has a suppressive effect on COX and iNOS RNA message in the lung and for this reason it should be avoided as an anesthetic when lung inflammatory processes are experimentally evaluated in the rat.