RESUMO
Oxidative stress affects the contractile behavior of smooth muscle resulting in complications during labor. Toxicants such as lindane and ferric chloride (FeCl3)/adenosine diphosphate (ADP) cause oxidative stress and have previously been shown to inhibit smooth muscle contraction. In this study we examined the effects of the oxygen species scavengers, ascorbic acid and N-acetylcysteine on lindane and FeCl3/ADP's inhibition of spontaneous myometrial contractions in rat and human myometrium. Lindane and FeCl3/ADP gave rise to concentration-dependent reductions in rat (EC50 11.8×10-6M and 0.9×10-3M) and human myometrial contractions (EC50 16.3×10-6M and 1.1×10-3M, respectively). Pre-treatment with N-acetylcysteine significantly increased the EC50 for the effects of lindane on motility index of human tissue and reduced the maximum inhibitory effect of FeCl3/ADP on contractions in both rat and human myometrium. Ascorbic acid reduced the effects of FeCl3/ADP in rat tissue only. In conclusion pre-treatment with specific antioxidants may protect both rat and human myometrium from the inhibitory effects of lindane and FeCl3/ADP.
