Vagina Of Ovariectomized Rats Research Articles

Effect of prolonged use of high dose of tibolone on the vagina of ovariectomized rats

The aim of this study was evaluate the effect of prolonged use of high dose of tibolone on the vagina of ovariectomized rats. Bilateral ovariectomy was performed on 14 rats weighing 250 g. Thirty days later, vaginal smears were collected verifying the menopause status by anoestrus cytology. Rats were divided randomly into groups: experimental rats (n = 9) received 1 mg tibolone/day orally and control rats (n = 6) received placebo (carboxymethylcellulose). After 150 days, all rats were sedated and euthanized by cervical displacement. The vagina was removed, fixed in 10% buffered formalin, sampled and processed for paraffin embedding. Histological sections were stained with haematoxylin and eosin, picrosirius red, periodic acid Schiff (PAS) and PAS-diastase, and Weigert's resorcin-fuchsin. Cell proliferation was analysed by immunohistochemistry to detect Ki67. Histomorphometric analyses were performed for epithelial thickness, per cent area of collagen fibres and blood vessels, mast cells and Ki67-positive nuclei per mm of basal membrane. Means and standard error of means were calculated, and data were compared using the Mann-Whitney test, with significance level at P < 0.05. In the vagina, epithelial thickness, number of Ki67-positive nuclei per mm of basal membrane, number of vessels and number of mast cells were significantly higher in the tibolone group when compared with the control group. Furthermore, the content of glycogen and glycoproteins in the vaginal epithelium was modified by tibolone. Tibolone administered in high dose and for a long period has a trophic effect, reversing vaginal atrophy, and has no dysplastic or neoplastic effect in the vagina of ovariectomized rats.

The soybean concentrated extract proliferates the vagina of adult rats

The aim of this study was to evaluate changes induced on the vagina of ovariectomized rats after treatment with soybean concentrated extract or conjugated equine estrogens and the association of both drugs. We conducted an experimental study with 50 ovariectomized rats that were randomly divided into five equal groups of 10 animals: GI received vehicle, GII received soybean concentrated extract 46 mg/kg per day, GIII received soybean concentrated extract 120 mg/kg per day, GIV received conjugated equine estrogens 50 μg/kg per day, and GV received conjugated equine estrogens 50 μg/kg and soybean concentrated extract 46 mg/kg per day. The substances were administered by gavage during 21 consecutive days. After that, the animals were killed under anesthesia and the vagina was removed for histological and immunohistochemical analysis. Data were initially submitted to analysis of variance. Whenever a significant difference was detected, the study was complemented with the Tukey-Kramer test for multiple comparisons. GII did not show any differences on the vaginal epithelium or collagen compared with GI. GIII presented an increase in vaginal epithelium and collagen amount. GIV had the highest amount of collagen and the signals of vaginal proliferation. GV did not show any additional effect compared with GIV. Our data suggest that a high dose of isoflavone-rich soy extract may have positive effects on the vaginal structures of ovariectomized rats, but this action is less than that of estrogen treatment on vaginal thickness. In addition, soy extract may not block the estrogen effect on vaginal tissue.

Influence of &lt;i&gt; Calotropis procera&lt;/i&gt; roots on biochemistry of reproductive organs of ovariectomized rats

iochemical alterations have been observed in the uterus, cervix and vagina of ovariectomized rats treated with alcoholic extract of Calotropis procera roots administered in the presence and absence of ethynilestradiol. Ovariectomy resulted in the decrease of glycogen and protein content as well as activity of acid and alkaline phosphatase in the uterus, cervix and vagina. Administration of the alcoholic extract of Calotropis procera increases glycogen and protein content and activity of acid and alkaline phosphatase in uterus and cervix with increasing weights, whereas, the glycogen contents decreased significantly in vagina. Combined treatments of the alcoholic extract with ethynilestradiol act synergistically confirm the estrogenic action of alcoholic extract of Calotropis procera roots in adult ovariectomized rats.

Estrogenicity of some nonsteroidal compounds

The estrogenicity of four nonsteroidal compounds found active as post-coital contraceptives in laboratory animals has been assessed on the basis of ponderal, histologic and biochemical changes in the uterus, cervix and the vagina of ovariectomized rats. The compounds are a benzofuran (2-phenyl-3-p-(β-pyrrolidinoethoxy) phenyl-6-methoxy benzofuran hydrochloride), a naphthofuran (2-phenyl-3-p-(β-pyrrolidinoethoxy) phenyl-naphtho (2,1-b) furan), a chroman (3,4-trans-2,2-dimethyl-3-phenyl-4-(p-(β-pyrrolidinoethoxy)-phenyl) 7-methoxy chroman) and a propiophenone (3-chloro-2, 3-diphenyl-propiophenone) derivative. It was observed that the estrogenicity of a compound varies depending upon the target organ and the type of parameter employed for assessment. It is pointed out that such difficulty might also arise as a result of different thresholds of the compound required for eliciting an estrogenic response, and also of its dissimilar absorption and retention by a particular target organ. Further, a compound might provoke an “estrogen-like” reaction which cannot be explained solely on the basis of its imputed estrogenicity.

Evidence for estradiol binding sites in the hypothalamus—Effect of drugs

One hr after i.v. injection, the concentration of 3H-estradiol in hypothalamus, anterior pituitary, uterus, and vagina of ovariectomized rats was lowered by prior administration of diethylstilbestrol, clomiphene, dimethylstilbestrol, U11100, or norethindrone. The concentration of 3H-estradiol in heart, cerebrum or plasma was little, if any, reduced by these drugs. Chlormadinone and medroxyprogesterone did not decrease the concentration of 3H-estradiol in any organ. These data support the thesis that binding sites for estradiol are present in the hypothalamus and that interaction by specific drugs with the estradiol-binding site in the hypothalamus may be a mechanism for regulation of ovulation.