Efeito dual do resveratrol em útero isolado de camundongos sob normóxia e hipóxia

Abstract

The effect of resveratrol in normoxic and hypoxic uterine was evaluated in this study. Resveratrol (1, 3, 10, 30, 100 μM) relaxed the uterus of mice and decreased the amplitude and frequency of uterine contractions. The polyphenol (3, 10, 30 uM) inhibited the oxytocin-induced cumulative contractions in the isolated uterus. The cumulative curves were shifted to the right in a non-parallel manner and with reduced Emax. The EC50 values increased from 9.2 ± 0.1 (control) to 3.1 ± 0.02, 2.9 ± 0.01 and 1.5 ± 0.03 in the presence of resveratrol. Noncompetitive antagonism was the confirmed effect. Resveratrol exhibited a regenerative effect after hypoxia. With resveratrol (% contraction = 51.18 ± 4.5), the uterus was five times more functional than without (contraction % = 10.67 ± 1.6). We observed that in the presence of resveratrol, after 10 minutes of hypoxia, the uterus was capable of approximately 75% contraction. We compared the effect of resveratrol with tempol and observed that resveratrol (% contraction = 51.18 ± 4.5) was three times better (% contraction = 19.73 ± 0.8). The effect of resveratrol (% contraction = 51.18 ± 4.5) was attenuated after incubation with tetraethyl ammonium (% contraction = 21.25 ± 1.9), indicating that potassium channels are involved in the effect of resveratrol in the hypoxic uterus. The effect of resveratrol (% contraction = 51.18 ± 4.5) was almost abolished following incubation with nifedipine (% contraction = 4.46 ± 1.4). We observed the participation of KATPs in the effect of resveratrol.