Light and electron microscopic study of the effect of low estroger level on the heart of adult female rats

ABSTRACT

Oestrogen has first been employed as a contraceptive either alone or combined with other hormone during the female reproductive life. It is known that its blood level decreases with age, when its withdrawal causes health problems. The morbidity and mortality from cardiovascular diseases and other health problems increase at the time this steroid is declining, hence hormonal replacement is recommended. Induction of low blood oestrogen level is attained through the administration of the non-steroidal antioestrogenic compound tamoxifen citrate [0.2 mg/100 gm b.w.]. Oestrogen compensation was achieved by the oestrogenic compound oestradiol benzoate [0.6 mg/100 gm b.w.], all administered subcutaneously three times weekly for 12 weeks. Forty adult female rats were divided into four groups often animals, they received saline solution [control], antioestrogen alone, oestrogen and its antagonist and oestrogen alone. The cardiac tissues were dissected out at the end of the experimental period, processed and stained with hematoxylin and eosin for light microscopy. Parallel tissue specimens were processed for E.M. study. The results have revealed many changes after the antioestrogen administration. Specifically, interstitial edema, splitting, destruction and necrosis of the myocardial fibers and cellular infiltration have been detected. At E.M. level, there have been marked destruction of myocardial filaments, cytoplasmic degeneration and swollen and destructed mitochondria. It was apparent that when oestrogen was administered with its antagonist, had reduced the untoward effects which were demonstrated in the cardiac tissues when exposed to the antioestrogen alone, although hemorrhagic areas, vascular congestion and endothelial cytoplasmic vaculations have been detected. Meantime, oestrogen alone did show mild adverse effect. This would explain the cardioprotectivity inherent in oestrogen whenever no contraindication for its employment is eminent