RESUMO
OBJECTIVE: To study the effect of AICAR on uterine smooth muscle of pregnant and nonpregnant rats. METHODS: The action of AICAR and dibutyryl-cAMP on the contractile function of isolated myometrium of pregnant and nonpregnant Sprague-Dawley rats was investigated. AICAR or dibutyryl-cAMP was used at cumulative doses from 10-9 to 10-4 mol · L-1 for myometrium of pregnant rats, and at 10-5 mol · L for myometrium of nonpregnant rats. The amplitude of the contractility of myometruim was recorded. RESULTS: For the myometrium of pregnant or nonpregnant rats, AICAR and dibutyryl-cAMP exerted strong inhibitory action on the contractile function in dose-dependent manners. For the myometrium of pregnant rats, AICAR or dibutyryl-cAMP showed inhibitory effect at a low concentration of 10-7 mol · L-1. AICAR and dibutyryl-cAMP also caused significant inhibition in myometrium from nonpregnant rats. CONCLUSION: AICAR exerted strong inhibitory action on the contractile function of myometrium from pregnant or nonpregnant rats, suggesting that AICAR may have inhibitory effect on spontaneous activity of myometrium of human.