[Chronic administration of estrogen receptors antagonist reduces degree of hypoxia-induced pulmonary hypertension caused by chronic injections of estrogen in ovariectomised female Wistar rats].

As we showed previously, administration of estradiol in different doses (5 and 15 mcg per day for 21 day) initiates the development of pulmonary arterial hypertension (PAH) in ovariectomised female Wistar rats. The aim of current study was to analyze the involvement of antagonist of estrogen receptors type a- and beta- ICI 182,780 (fulvestrant) in development of hypoxia-induced pulmonary arterial hypertension. Ovariectomised female rats were separated into 5 groups received subcutaneously for 1 month : 1. Estrogen 15 mcg per day. 2. Estrogen 60 mcg per day 3. Antagonist of estrogen receptors type alpha- and beta- fulvestrant 150 mcg per day. 4. Estrogen 15 mcg/d + fulvestrant 150 mcg/d. 5. Propylenglycol as a control group. PAH was induced by exposure to hypobaric hypoxia. Rats were housed in a hypobaric chamber at simulated altitude of 5000 m, 10 h a day, 2 wk (O2 concentration reduced to 10%). We suppose that the development of pulmonary hypertension in ovariectomised female Wistar rats caused by administration of estrogen (15 mcg and 60 mcg per day for 1 month) is mediated by estrogen receptors type alpha- and beta-.