Efeitos das isoflavonas sobre o miométrio de ratas adultas

Abstract

RESUMOObjetivo: avaliar as alterações no miométrio de ratas após o tratamento com isoflavonas, comparando-as às dos estrogênios, por técnicas histológicas e morfométricas. Métodos: 28 ratas adultas castradas foram divididas, ao acaso, em quatro grupos que receberam: GPropi -propilenoglicol; GExtr10 -extrato de soja (10 mg/kg por dia); GExtr300 -extrato de soja (300 mg/kg por dia) e GEce -estrogênios conjugados eqüinos (Ece -200 µg/kg por dia). Após 21 dias de tratamento, todos os animais foram sacrificados, os úteros retirados e pesados, e fragmentos dos cornos uterinos foram coletados e fixados em formol a 10% e processados para inclusão em parafina. Os cortes histológicos foram corados pela hematoxilina e eosina e examinados em microscópio acoplado a analisador de imagens para avaliação da espessura, número de vasos sanguíneos e de eosinófilos no miométrio. Os resultados obtidos foram submetidos à análise de variância (ANOVA), seguida pelo teste de comparações múltiplas de Tukey-Kramer. Resultados: as isoflavonas, na concentração de 300 mg/kg, induziram aumento significante na espessura do miométrio (GExtr300=25,6±5,0 mm) em relação ao controle (GPropi=5,5±0,5 mm). O efeito desta alta é comparável ao efeito dos estrogênios (GEce=27,5±7,9 mm). Em doses baixas (10 mg/kg), os valores foram similares ao controle. Além disso, as isoflavonas (GExtr300) induziram aumento no número de vasos sangüíneos (GExtr300=10,2±3,6/mm 2 ; GPropi=3,5±1,6 vasos/mm 2 ) e de eosinófilos (GExtr300=4,3±0,9; GPropi=0,15±0,01 eosinófilos/mm 2 ), igualmente comparáveis aos efeitos obtidos pelo tratamento com Ece (GEce=9,2±1,1 eosinophils/mm 2 ). Conclusão: as isoflavonas em doses altas (300 mg/kg por dia, durante 21 dias) têm efeito proliferativo no miométrio de ratas, semelhante ao dos estrogênios. PALAVRAS-CHAVE:Isoflavonas; Estrogênios; Miométrio; Estudo experimental ABSTRACT Purpose: to evaluate histomorphometric changes in the rat myometrium upon treatment with isoflavones, as compared with estrogens, using histological and morphometric techniques. Methods: twenty-eight oophorectomized adult rats were randomly divided into four treatment groups: GPropi = propylene glycol (control); GExtr10 -10 mg/kg soybean extract; GExtr300 -300 mg/kg soy bean extract; GCee -200 µg/kg conjugated equine estrogens (Cee). Drugs or drug vehicle were administered by gavage once a day for 21 days. Upon sacrifice, the uteri were removed and weighed. Fragments of uterine horns were collected and fixed in 10% formaldehyde and processed for paraffin inclusion. The histological sections were stained by hematoxylin and eosin and evaluated microscopically by means of an image analyzer to quantify the myometrial thickness and the number of blood vessels and eosinophils. The data were studied by analysis of variance (ANOVA) followed by the Tukey-Kramer multiple comparison test. Results: isoflavones in the concentration of 300 mg/kg induced a significant increase in the myometrium thickness (GExtr300=25.6±5.0 mm) compared to control (GPropi=5.5±0.5 mm). The effect ...

Effects of estrogen-like plant compounds on the vaginal epithelium pituitary, adrenal glands, and uterus of rats

“…This may indicate that isoflavones have a selective action and exhibit estrogenic activity only in specific tissues. Mosquette et al 34 described uterine changes in ovariectomized rats when isoflavones at doses of 300 mg/kg/day or higher were administered to rats over a 21-day period. Furthermore, Ribeiro et al, 35 treating hypoestrogenic rats with soybean isoflavones (100 mg/kg/day) during a prolonged period, found that a low dose of isoflavone was not sufficient to promote uterine development.…”

Comportamento das reservas de glicogênio no músculo desnervado de ratas tratadas com diferentes doses de estrógeno

“…Regarding the effect of different doses of estradiol, assessment began with the concentrations of 20 and 40µg/ weight/ day, which are considered low doses with little effect on various biological systems 10,20,21 . This analysis showed a significant increase in glycogen reserves, although with a lower expression in the mixed gastrocnemius muscles, indicating that microdoses can activate metabolic parameters but not homogeneously.…”

“…In the area of women's health, the study of estrogen actions is essential to understanding the organic changes that take place in periods of lower hormonal production, causing various symptoms such as hot flashes, mood swings and loss of bone and muscle mass, which hormone replacement therapy seeks to minimize 9 . With regard to the unwanted side effects associated with hormone therapy with high doses of estrogen, data show an increase in the relative risk of some hormonedependent breast and endometrial neoplasias, as well as an increase in the risk of cardiovascular diseases, thromboembolism, mastalgia, weight gain and change in lipid profile 10 . It should be pointed out that a recent study indicates that estrogen treatment can modify antioxidant capacity in fibers, decreasing changes generated by muscle injuries and accelerating the regeneration process.…”