Search

Objective: To evaluate the histomorphometric and immunohistochemical changes in interstitial cells and ovarian follicles of rats treated with clomiphene citrate during and after induction of permanent estrus., Methods: Twenty four adult-female rats with regular estrous cycle were equally divided into three groups: (1) GCtrl-at estrous phase. (2) GPCOS-at permanent-estrous phase. (3) GCC-PCOS rats, which remained exposed to 60 days of continuous illumination and treated with Clomiphene Citrate. After that, the animals were euthanized, and the ovaries were removed and processed for paraffin embedding. Sections were stained with H.E. for histomorphometry or subjected to immunohistochemistry for Ki-67 and cleaved caspase-3 detections., Results: The GPCOS showed lack of corpus luteum and several ovarian cysts, as well as interstitial-like cells. The presence of corpus luteum and a significant increase in primary and antral follicles were observed in GCC, which also showed a decrease in the number of ovarian cysts and in the area occupied by interstitial-like cells, as well as a decrease in nuclear volume of interstitial cells. The percentage of cell proliferation was significantly higher in granulosa cells of the GCC. On the other hand, the percentage of apoptosis was significantly higher in the granulosa cells of GPCOS than the GCC., Conclusion: The ovaries of rats treated with clomiphene citrate showed a decrease in the number of cysts, an increase in the number of ovarian follicles, the presence of corpus luteum along with a decrease in the nuclear volume in the area occupied by interstitial cells.

Aim: Although soy isoflavones (ISO) have been shown to relief postmenopausal symptoms, it remains inconclusive whether ISO can improve lipid-profile without uterotrophic effects under estrogen-deficiency. Thus, we investigated the effects of ISO on lipid-profile and uterus of ovariectomized (Ovx) rats., Materials and Methods: Twenty-five adult rats were Ovx or Sham-operated (Sham) and assigned into five groups: Sham and Ovx groups, administered with vehicle solutions; Ovx-E, treated with 10 µg/kg of 17β-Estradiol; Ovx-ISO, treated with 200 mg/kg of ISO; Ovx-E + ISO, treated with estradiol + ISO combined. After fifty days of treatments, rats were euthanized and uterine horns were processed for histomorphometry or to collagen fibers and glycosaminoglycans evaluations. Blood samples were collected to evaluate levels of triglycerides, total cholesterol (TC) and its fractions (HDL/VLDL). Data were subjected to statistical analysis ( p  < .05)., Results: Uterus weight was lower in Ovx group than the Sham and Ovx-E groups, whereas it was similar between Ovx and Ovx-ISO groups. Histomorphometry showed atrophic uterus in Ovx and Ovx-ISO groups, whereas uterotrophic effects were noticed in Ovx-E and Ovx-E + ISO groups. Collagen fibers-birefringence was higher in Sham, Ovx, and Ovx-ISO groups than in Ovx-E and Ovx-E + ISO groups. Sulfated glycosaminoglycans content was similar among Sham, Ovx, and Ovx-ISO groups, while it was higher in estrogen-treated groups; total glycosaminoglycans content was similar among groups. TC and HDL was higher in Ovx-ISO group, whereas VLDL and triglycerides levels was higher in Ovx-E + ISO group and similar among other groups., Conclusion: Soy isoflavones at 200 mg/kg have slight beneficial effects on lipid-profile without uterotrophic effects in Ovx rats.

Ovarian aging is characterized by declines in follicular reserve and oocyte quality due, in part, to increased oxidative stress and apoptosis. Soy isoflavones (ISOs) have been shown to improve ovarian lifespan by acting as antioxidant and antiapoptotic agents. We aimed at evaluating whether ISOs could modulate oxidative stress and reduce apoptosis and improve ovarian follicle survival in middle-aged female rats. Twelve ovary-intact female Wistar rats (12-month-old) were divided into groups: control (CTRL) and ISO, daily treated by gavage with vehicle or soy-ISO extract (150 mg/kg b.w), respectively. After 8 weeks, rats were euthanized and their ovaries removed for histomorphometric (% follicles) and apoptosis (cleaved-caspase-3/BCL2 immunostaining) evaluations, or subjected to biochemical assays to survey reactive oxygen species (ROS) and lipid peroxidation levels and total antioxidant capacity (TAC). The frequency of atretic follicles and number of cleaved-caspase-3-positive cells, as well as the ROS and lipid peroxidation levels, were significantly lower in ISO group compared to CTRL. A significantly higher number of BCL2-positive cells and TAC levels were also observed in ISO group. In conclusion, soy ISOs could decrease follicular atresia, apoptosis and oxidative stress, as well as increase the TAC in ovaries of female rats.

Aim: To evaluate the combined effects of streptozotocin-induced diabetes (Di) and ovariectomy in the articular cartilage of rats., Methods: Forty adult female Wistar rats were ovariectomized (OVX) or sham-operated. After recovery from surgery, the animals were assigned randomly into four groups: OVX control (OVX-C); OVX treated with 10 µg/kg/day of 17β-estradiol (OVX-E); sham-operated subjected to Di (Sham-Di); and OVX subjected to Di (OVX-Di). After 60 days of treatment, the animals were euthanized and the distal femurs with articular cartilage were processed for paraffin-embedding. Sections were stained with hematoxylin and eosin for histomorphometry, Picro-Sirius Red for collagen, or Alcian Blue for glycosaminoglycan (GAG) content. To detect apoptosis, sections were stained with an antibody to cleaved caspase-3 (casp-3)., Results: Articular cartilage thickness and GAG content were significantly lower (p < 0.05) in the OVX-Di group, which also showed a higher number of casp-3-positive chondrocytes than the other groups. Interestingly, the higher percentage (p < 0.05) of mature collagen fibers was seen in the OVX-Di group, may be as a result of a reduced extracellular matrix remodeling of the articular cartilage., Conclusion: Our results indicate that the combination of ovariectomy and streptozotocin-induced diabetes produces more deleterious effects in articular cartilage of rats than either condition alone.

Introduction: Soy isoflavones have been shown to be an alternative to hormone therapy at menopause, without causing side-effects such as breast cancer. However, the effects of early and late treatment with isoflavones on the mammary gland remain controversial., Objective: To investigate the effects of early and late treatment with soy isoflavones on the mammary gland of ovariectomized rats., Methods: Thirty 3-month-old rats were ovariectomized and divided equally into groups: Control, treated with vehicle solution; or with 150 mg/kg/body weight of isoflavones by gavage; or subcutaneously treated with 10 μg/kg/body weight with 17β-estradiol. Treatments started 3 days (early treatment) or 30 days (late treatment) after ovariectomy and lasted for 30 consecutive days. Thereafter, the animals were euthanized and the mammary glands were removed and processed for paraffin embedding. Sections were stained with hematoxylin and eosin for histomorphometry or subjected to immunohistochemical detection of Ki-67 and VEGF-A., Results: The ductal, lobular and total epithelial fractions were similar between controls and the early/late isoflavone groups, but they were significantly higher in the groups treated with estradiol. In both epithelial and stromal regions, the immunoreactivity of VEGF-A and the percentage of Ki-67-positive cells were significantly higher in the groups treated with estradiol, while they were similar in the early/late isoflavone groups and control groups., Conclusion: Our results indicate that early and late treatment with soy isoflavones at the dose of 150 mg/kg/body weight does not show proliferative and angiogenic effects on the mammary gland of ovariectomized rats.

Low-intensity, high-frequency mechanical vibration (LHMV) has shown to increase bone formation. However, studies comparing the effectiveness of early- and late-treatments of LHMV to counteract bone loss have not been documented. This study was designed to compare the effects of early- and late-treatments of LHMV (at 30 Hz/0.6 g, 20 min per day/five days per week, for 12 weeks) on bone parameters in ovariectomized (Ovx) rats. Thirty days after ovariectomy, 40 adult rats were randomly divided into four groups: GI (early control group); GII treated with LHMV 3 weeks after Ovx (early treatment); GIII (late control group) and GIV treated with LHMV twelve weeks after Ovx (late treatment). Bone mineral density (BMD) was analyzed before Ovx and after treatments. Then, animals were killed, and the femurs were collected and their length and diaphysis diameter were measured; the distal femurs were taken and processed for histomorphometry and polarized light microscopy for collagen fibers analysis or subjected to immunohistochemistry of cleaved caspase-3 in osteocytes. Statistical analysis was done by ANOVA followed by the Bonferroni post hoc test (p < 0.05). BMD was similar among the groups before Ovx, but after treatments, it was significantly higher in GII and GIV compared with their control groups (p < 0.05). Femur length and cortical bone thickness were similar among the groups, but the diaphysis diameter of GII was higher compared with GI. Trabecular bone area was higher in the vibrated groups, but it was greater in GII (p < 0.05). Also, the vibrated groups showed the higher content collagen fibers and lower presence apoptotic osteocytes (positive caspase-3 immunoreactivity) when compared with the other groups (p < 0.05). These results suggest that both early- and late-treatments with LHMV counteract bone loss, being the early treatment more effective than the late treatment.

Aim: Studies report that hormone replacement prevents osteoporosis, but there are doubts whether isoflavones are really efficient in this process. The aim of this study was to evaluate the effects of different doses of soy isoflavones on bone tissue of ovariectomized rats., Methods: Forty female rats at the age of 6 months were ovariectomized and, after 3 months, the animals were divided into four groups: GI - Control (treated with drug vehicle); GII - treated with isoflavones (80 mg/kg per day); GIII - treated with isoflavones (200 mg/kg per day) and GIV - treated with isoflavones (350 mg/kg per day). Soy isoflavones were administered by gavage for 90 consecutive days. After treatment, the rats were euthanized and their distal femurs were removed for histological routine, histochemistry and biochemical study. Histological sections were stained with hematoxylin-eosin or subjected to picrosirius red and alcian blue methods. Shafts of femurs were submitted to biochemical assay and tibias were subjected to biophysical and biomechanical tests., Results: In distal femurs, the trabecular bone volume was higher in the groups treated with isoflavones, being higher in GIV, while the cortical bone width and the presence of mature type I collagen fibers were higher in GII. At the trabecular bone region, the percentage of total glycosaminoglycans (GAGs) was higher in GII and the percentage of only sulfated GAGs was higher in GIII, while the higher content of chondroitin sulfate in shafts of femurs was seen in GIV. Biophysical and biomechanical tests in tibias did not differ among the groups., Conclusion: Our data indicate that soy isoflavones improve bone quality in femurs of rats by increasing histomorphometric parameters, the content of GAGs and mature type I collagen fibers. These positive effects are dose-dependent and it was different in cortical and trabecular bone.

Objective: To investigate the effects of soy isoflavones (Iso) and mechanical vibration treatments alone or combined on bone extracellular matrix constituents of ovariectomized rats., Methods: Forty female Wistar rats at the age of 6 months were ovariectomized (Ovx) and ten were sham-operated (sham). After 3 months, the animals were divided into five groups: GI (sham); GII (Ovx); GIII, ovariectomized and orally treated with isoflavones (200 mg/kg) for 90 consecutive days; GIV, ovariectomized and submitted to vibration for 90 days (5 days/week); GV, ovariectomized and treated with isoflavones plus vibration. After treatments, the rats were euthanized, and their femurs were removed for histological routine and biochemical study. Histological sections were stained with hematoxylin-eosin, picrosirius red and alcian blue. Shaft of femurs were submitted to biochemical assay and tibias were subjected to biophysical and biomechanical tests., Results: Treatments did not have significant effects on the trabecular bone volume, but the combined treatments showed trophic effects on the cortical bone width and area. Bone density and the content of organic material of the tibias were higher in the GIV and GV groups. The GV group showed the highest presence of mature collagen fibers and content of total glycosaminoglycans, while the highest contents of chondroitin sulfate and other sulfated glycosaminoglycans were seen in the GIV group., Conclusion: The mechanical vibration treatment is more efficient than soy isoflavones in improving bone quality by increasing the bone density, the content of sulfated glycosaminoglycans and the presence of mature collagen fibers. In addition, the combined interventions have partial trophic and synergistic effects that are bone site-specific in ovariectomized rats.