Effects of Sex Hormones on Nociception and the Analgesic Action of NSAIDs / 대한마취과학회지

ABSTRACT

BACKGROUND: The effects of sex hormones on nociception and the analgesic actions of non-steroidal anti-inflammatory drugs (NSAIDs) in an acute arthritic pain model were investigated. METHODS: Rats were ovariectomized and randomly assigned to three experimental groups. The estrogen group (n = 45) received a 0.25 mg pellet of 17beta-estradiol, the placebo group (n = 45) received a 0.25 mg pellet of a placebo and the progesterone group (n = 45) received a 25 mg pellet of progesterone. Arthritis was induced by injecting 2% carrageenan into the knee joint cavity of the right hind leg. Before and after the injection, rats were allowed to walk freely through a weight load apparatus. The weight load and the weight of the rat were measured for each test. One hour after injection, ibuprofen or NS-398, dissolved in dimethyl sulfoxide, was injected intraperitoneally (1 mg/kg/ml). RESULTS: The carrageenan injection into the knee joint cavity of the right hind leg of the rat resulted in a significant decrease in the weight load on the injected leg. Estrogen-treated rats showed lower weight load reduction than the placebo and progesterone groups, NS-398 increased the weight load compared to rats not receiving NSAIDs. CONCLUSIONS: These results suggest that the nociceptive response after acute inflammation was reduced by estrogen, and that only NS-398 had a good analgesic effect in the placebo and progesterone groups. It is likely that the analgesic effect of NSAIDs on the estrogen group was unremarkable compared to those of the placebo and progesterone groups because of the antinociceptive action of estrogen.