Effect of ketamine on the cGMP level in different brain areas in a rat model of CFA-induced arthritis / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of ketamine on the cGMP content in cerebral cortex, hypothalamus and brain stem in a rat model of CFA-induced arthritis. Methods Twenty-four SD rats weighing 200-220 g were randomly divided into three groups with 8 animals in each group, group Ⅰ normal rat + intraperitoneal normal saline (ip NS);group Ⅱ arthritic rat+ ip NS;group Ⅲ arthritic rat + ip ketamine 100mg?kg-1 . Arthritis was produced by injecting CFA 0.05 ml into left ankle joint which developed inflammatory response within 24h and became hyperalgesic. The hyperalgesia persisted for more than 6 weeks. Three days after the arthritis model was established, paw withdrawal latency (PWL) to radiant heat was measured. 15 min after ip ketamine the animals were decapitated and cerebral cortex, hypothalamus and brain stem were separately isolated for determination of cGMP content using radioimmunoassay. Results In arthritic rats the PWL was significantly shortert (6.7 ? 1.2)s] than that in the normai rats [(12.5?1.9)s] ( P