بررسي نقش واسطه اي نيتريك اكسايد () در تاثير هورمون هاي استروژن و پروژسترون بر اضطراب در موش صحرايي ماده

Possible involvement of nitric oxide (NO) in anxiety-like behavior induced by female steroid hormones

Introduction. Nitric oxide (NO) is a neuromodulator and an intercellular messenger that mediate several functions in the CNS. Possible involvement of NO in anxiety like behavior induced by ovarian hormones was studied in ovarectomized female rats. Materials and Methods. 12 groups of rats were ovarectomized bilateraly and 14 days after surgery they received estradiol benzoat (10 /ig/kg, sc) and or progesterone (25 mg/kg, sc) or corn oil (0.2 ml/rat, sc) and L-Name (60 mg/kg,i.p) or L-Aarginine (100 mg/kg,i.p) or normal saline (0.5 ml/rat, i.p). The behavioral tests began 6 hours after progesterone and 3 hours after estradiol administeration. Behavioural test consisted measurment of exploratory activities on elevated plus maze test. Results. There was increased exploration of open arms under progesterone administeration alone or with L-Name, and decreased under estradiol administeration alone or with L-Arginine. The anxiolytic-like effect of progesterone abolished when L-Arginine administerated, and anxiogenic-like effect of estradiol was inhibited when L-Name injected. Conclusion. These data indicate involvement of NO in the mediation of the effects of ovarian steroid hormones on anxiety process.