Isoflavones improve collagen I and glycosaminoglycans and prevent bone loss in type 1 diabetic rats.

Objective: The objective of this study was to evaluate the action of soy isoflavones (ISO) and 17ß-estradiol on collagen I (CollI) and sulfated glycosaminoglycans (GAGs) in the bone matrix of diabetic rats.Methods: Sixty adult female rats (Rattus norvegicus albinus) underwent ovariectomy, and then were randomized into six groups of 10 animals each: GI, sham control ovariectomized animals; GII, sham control diabetic (DM) ovariectomized animals; GIII, control ovariectomized animals receiving propylene glycol vehicle; GIV, control ovariectomized DM animals receiving propylene glycol vehicle; GV, ovariectomized DM animals treated with ISO (150 mg/kg by gavage); and GVI, ovariectomized DM animals treated with estrogen (17ß-estradiol, 10 mg/kg, subcutaneously). 17ß-Estradiol was used as a positive control when compared with ISO. To obtain significant depletion of the estrogen levels and subsequent bone loss, a postsurgical period of 90 days was observed. Treatments occurred during 30 consecutive days. After euthanasia, shafts of the animals' femurs were immersed in liquid nitrogen for molecular biology analysis, and the distal femurs were removed and processed for paraffin embedding.Results: ISO (GV) and 17ß-estradiol (GVI) improved bone formation, increasing GAGs and CollI formation when compared to the control group (GIV) (p < 0.05).Conclusions: ISO and 17ß-estradiol contribute to the decrease of bone loss in diabetic rats.

Soy isoflavones protect against oxidative stress and diminish apoptosis in ovary of middle-aged female 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.

Combined effects of ovariectomy and streptozotocin-induced diabetes in the articular cartilage of 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 17ß-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.

Effects of early and late treatment with soy isoflavones in the mammary gland of ovariectomized rats.

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 17ß-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.

Highly active antiretroviral therapy during gestation: effects on a rat model of pregnancy.

OBJECTIVE: To assess the adverse effects of the chronic use of zidovudine/lopinavir/ritonavir in a rat pregnancy model.Type of article: Original paper. DESIGN: A prospective experimental study. SETTING: Department of Obstetrics, São Paulo Federal University (UNIFESP). METHODS: 40 pregnant EPM-1 albino rats were randomly allocated into four groups of 10 animals each: control (Ctrl) group (untreated) and three experimental groups (Exp1, Exp2 and Exp3), which received zidovudine/lopinavir/ritonavir in the corresponding doses of 10/13.3/3.3; 30/39.9/9.9 and 90/119.7/29.7 mg/Kg/day from the first up to the 20th day of pregnancy, respectively. The rats were treated by gavage daily. Body weights were recorded on days 0, 7, 14 and 20. At term, the rats were sacrificed and the implantation sites, number of live and dead fetuses and placentas, resorptions and fetal and placental weights were recorded. The fetuses were evaluated for external abnormalities under a stereomicroscope. The chi-square test was used to compare death rates between groups. RESULTS: Weight gain during pregnancy no showed significant differences between groups. Average weight gains between the 7th and 20th day were 45.70 ± 5.27 g for Ctrl; 48.49 ± 3.64 g for Exp1; 45.39 ± 6.22 g for Exp2 and 44.19 ± 6.78 g for Exp3. However, the percentage weight gain in the 7th was lower in groups Exp2 and Exp3 and in the 14th in the Group Exp2. All other parameters assessed did not differ significantly between groups. Exp2 and Exp3 in relation of the others. CONCLUSIONS: The chronic exposure of pregnant rats to high doses of zidovudine/lopinavir/ritonavir in association resulted in a significant reduction in maternal body weight gain but was not associated with significant adverse fetal parameters.

Soybean concentrated extract counteracts oxidative stress in the uterus of rats.

OBJECTIVE: To evaluate the effects of soy isoflavone extract in the pro-oxidant/antioxidant balance in the uterus of ovariectomized rats. METHODS: Twenty 3-month-old adult female Wistar rats were divided into four equal groups: GI: sham-operated (estrous phase); GII: control ovariectomized rats; GIII: ovariectomized rats treated with genistein (50 µg/kg/day) by gavage; GIV: ovariectomized rats subcutaneously treated with estrogen (10 µg/kg/day). After 30 consecutive days of treatment, the rats were euthanized and the uterus removed. The distal thirds of the uterine horns were processed for histomorphometric analyses of endometrial and myometrial thicknesses and glandular area. Other regions of the uteri were kept in liquid nitrogen and subsequently processed for analysis of reactive species quantification (DCF), total antioxidant capacity (TAC) and lipid oxidation status (TBARS). Data were statistically analyzed by one-way ANOVA, complemented by the Tukey-Kramer test (p < 0.05). RESULTS: GII and GIII exhibited lower endometrial thickness, glandular area and myometrial thickness than GI and GIV, while a higher myometrial thickness was observed in GIV compared with the other groups. Moreover, the isoflavone-treated group showed lower DCF and TBARS compared to GII, and also an improvement of TAC compared to GI and GIV. Despite the significant decrease in TBARS, no significant difference in DCF nor a decrease in TAC were observed in GIV when compared to GII. CONCLUSION: Our data show that isoflavones improve antioxidant status and counteract oxidative stress, without promoting a trophic effect in the uterus of rats.

Effects of combined zidovudine/lopinavir/ritonavir therapy during rat pregnancy: morphological aspects.

PURPOSE: To evaluate the morphological aspects in rats subjected to an association of the antiretroviral drugs zidovudine/lopinavir/ritonavir in different doses administered throughout the gestational period. MATERIALS AND METHODS: Forty pregnant rats were randomly allocated into four groups: control (Ctrl) and experimental (Exp1, Exp2, and Exp3), which received zidovudine/lopinavir/ritonavir in the doses of 10/13.3/3.3, 30/39.9/9.9, and 90/119.7/29.7 mg/kg per day from the first to the 20th day of pregnancy, respectively. At term, the animals were euthanized and maternal and fetal organ samples were removed for morphological analysis. RESULTS: No major changes were identified in the group treated with the lowest dosing compared with the control. In group Exp2, the authors found hepatocytes with eosinophilic cytoplasm, pyknotic nuclei, and vasodilation. The proximal convoluted tubules of maternal kidneys showed eosinophilic areas and hyperchromatic nuclei, as well as signs of vasodilation. In the group treated with the highest dose (Exp3); the morphological changes in the maternal kidneys and livers were similar and more pronounced than those found in Exp2. The maternal pancreas of groups Exp2 and Exp3 evidenced moderate and progressive signs of tissue damage. The morphological features of all fetal livers, kidneys, and pancreases were normal. CONCLUSION: High doses of zidovudine/lopinavir/ritonavir association during the entire rat pregnancy period can cause definite morphological changes in maternal liver, kidneys, and pancreas. On the other hand, the corresponding fetal organs were not affected.

Administration of lopinavir/ritonavir association during rat pregnancy: maternal and fetal effects.

PURPOSE: To evaluate the effects of the association of lopinavir and ritonavir administered during the whole period of rat pregnancy. METHODS: 62 Wistar rats of the EPM-1 variant weighing about 200 g were randomly divided into five groups: two controls (Ctrl = stress control, n = 10; and Ctr2 = drug vehicle control, n = 10) and three experimental ones which were treated with an oral solution of lopinavir/ritonavir (Exp1 = 12.8/3.2 mg/kg b.w., n = 14; Exp2 = 38.4/9.6 mg/kg b.w., n = 14; Exp3 = 115.2/28.8 mg/kg b.w., n = 14) from 'day 0' up to the 20th day of pregnancy. Maternal body weight was recorded at the start of the experiment and on the 7th, 14th and 20th day thereafter. At term (20th day), upon laparotomy and hysterotomy, the rats were anesthetized and the amount of implantations, reabsorptions, living fetuses, placentae and intrauterine deaths were recorded. The collected fetuses and placentae were weighed and the concepts were examined under a stereoscope microscope for external malformations. RESULTS: An apparent dose-unrelated lethal effect of the antiviral association on the pregnant rats was observed; notwithstanding, the body weight gain of the surviving rats had no changes, independent of the considered group. It was noted that the quantitative and qualitative intrauterine content of living term rats was indistinguishable from that of the controls. CONCLUSION: There was some degree of deleterious effects of the administration of the lopinavir/ritonavir association on pregnant rats; such effects eventually led to maternal death. However, neither the surviving rats showed toxicity nor did their concepts present any detectable change which could be related to the drug association.

Do extracts of oral soybean augment the trophic effect of estrogen on the rat uterus?

OBJECTIVE: To evaluate whether soybean extracts and estrogens present additive effects on adult rat uterus. METHODS: Fifty ovariectomized rats were randomly divided into five equal groups of ten animals: Control, treated with vehicle; SE46 and SE120, treated with 46 and 120 mg/kg soybean concentrated extract (SE), respectively; EE, treated with conjugated equine estrogens (CE) 50 µg/kg; SE120 + EE, treated with 50 µg/kg (CE) plus 120 mg/kg SE. The substances were administered daily by gavage for 21 consecutive days. Thereafter the animals were weighed and killed by decapitation; trunk blood was collected for hormone determinations. Uteri were removed immediately and fixed in 10% formaldehyde, followed by dehydration, embedding in paraffin and 6-m sections staining with hematoxylin and eosin for histomorphometric analyses of myometrium and endometrium. After ANOVA analysis of the data, the study was complemented with the Tukey-Kramer test for multiple comparisons. RESULTS: The concentrated extract of soybean at high concentration (SE 120 kg/mg) and estrogens proved to have a trophic effect on the uterus (endometrium and myometrium) of castrated rats. In groups SE120, EE and SE120 + EE, all morphometric parameters examined (number of glands, eosinophils, blood vessels and the glandular area) were increased. No significant addictive effects of soybean extract plus estrogens were detected in the SE120 + EE group. CONCLUSIONS: Our results indicate that soy extract has a trophic effect on rat uterine structures. Treatment of ovariectomized rats with a concentrated soy extract in combination with conjugated estrogens had no addictive effect on the uterine response.

Tomografia computadorizada da matriz óssea mineralizada heteróloga fragmentada e metilmetacrilato na reparação de falhas ósseas segmentares produzidas em tíbia de coelhos / Computed tomography to evaluate the association of fragmented heterolog cortical bone and methylmethacrylate to repare segmental bone defect produced in tibia of rabbits

Foi realizada falha segmentar de 6mm na região metafisária medial da tíbia de 12 coelhos, seguida de preenchimento desta por matriz óssea mineralizada heteróloga fragmentada conservada em glicerina (98%) e metilmetacrilato autoclavado, bem como avaliação por meio da tomografia computadorizada de feixe cônico (cone beam) aos 30, 60 e 90 dias. Houve incorporação gradativa do implante no leito receptor em relação ao tempo em 100% dos casos, o que mostra ser este biologicamente compatível, ao promover reparação da falha óssea, sem sinais de infecção, migração e/ou rejeição, caracterizando-se, assim, como nova opção de substituto ósseo para preenchimento de falhas ósseas.

A 6mm segmental defect was performed on the metaphyseal region of the tibia of 12 rabbits and the autoclaved fragmented heterolog cortical bone conserved in glycerin (98%) and methylmethacrylate was used as a bone graft for the reconstruction. The graft was placed in the receptor bed and its integration was evaluated by computed tomography after 30, 60 and 90 days. There was gradual bone graft incorporation in the receptor bed during the time in 100% of the cases. Fragmented cortical bone heterograft and methylmethacrylate was biologically compatible and promotes bone defect reparation without signs of infection, migration and or rejection, featuring a new option of osseous substitute to fill in bone defects.

Effects of daily intake of zidovudine-stavudine on rat pregnancy outcome: biological essay.

PURPOSE: To evaluate the effects at term of a highly active antiretroviral drug association when administered for the whole period of rat pregnancy. METHODS: Forty pregnant rats weighing about 200 g were randomly divided into four groups: a control group (Ctr = drug vehicle control, n=10) and three experimental groups, which were treated with an oral solution of zidovudine-stavudine (Explx = 10/1 mg/kg b.w., n=10; Exp3x = 30/3 mg/kg b.w., n=10; Exp9x = 90/9 mg/kg b.w., n=10) from "day 0" up to the 20th day of pregnancy. Maternal body weights were recorded at the start of the experiment and on the 7th, 14th and 20th day thereafter. At term (20th day) the rats were anesthetized and submitted to hysterotomy. Implantations, reabsorptions, living fetuses, placentae and intrauterine deaths were looked for and recorded. The collected fetuses and placentae were weighed and the concepts were examined by a stereoscopic microscope looking for external malformations. RESULTS: No significant alterations due to the antiretroviral drug treatment could be detected regarding the number of implantations, fetuses, placentae, absorptions and malformations nor regarding maternal and fetal mortality. CONCLUSIONS: Administration of the association zidovudine/stavudine for the whole period of rat pregnancy did not interfere with the maternal, fetal and placental weight gain as well as abnormalities detectable by the employed methodology.

Effects of the association zidovudine plus ritonavir on the liver and kidneys of pregnant rats. Morphological and biochemical aspects.

PURPOSE: To evaluate biochemical and morphological effects on rats submitted to three different doses of the association zidovudine and ritonavir administered throughout pregnancy. METHODS: Forty pregnant EPM-1 Wistar rats weighing about 200 g were randomly divided into the control group (Ctr = drug vehicle control, n = 10) and three experimental ones which were treated with an oral solution of zidovudine/ritonavir (Exp1 = 10/20 mg/kg bw, n = 10; Exp2 = 30/60 mg/kg bw, n = 10; Exp3 = 90/180 mg/kg bw, n = 10) from 'day 0' up to the 20th day of pregnancy. At term (20th day) the rats were anesthetized. Blood and fetal and maternal organ samples (livers and kidneys) were taken for morphological and biochemical analyses. RESULTS: Upon histological examinations fetal livers and kidneys appeared normal. In contrast the maternal samples revealed structural alterations. Maternal kidneys of the three experimental groups exhibited progressive and dose-dependent histological alterations; liver alterations were detected only in Exp3. Blood levels of AST and ALT were not significantly different from the control group but urea and creatinine levels were lower in groups Exp3 and Exp1. CONCLUSIONS: The administration of zidovudine plus ritonavir throughout rat pregnancy can cause morphological as well as functional changes in maternal kidneys.

Chronic action of association of zidovudine, lamivudine and ritonavir on pregnant rats. A biologic assay.

PURPOSE: To evaluate at term the effects of a highly active antiretroviral (HAAR) drug association administered during the entire period of rat pregnancy. METHODS: Three groups (n = 10 each) of adult pregnant rats were treated with an oral solution of HAAR (Exp 1 = 10/5/20 mg/kg b.w.; Exp 2 = 30/15/60 mg/kg b.w.; Exp 3 = 90/45/180 mg/kg b.w.) from day "0" up to the 20th day of pregnancy. A fourth group served as a control. At term (20th day) the rats were killed under deep anesthesia and the number of implantations, resorptions, living fetuses, placentae and intrauterine deaths were recorded. RESULTS: The highest HAAR doses caused lower maternal weight gain, lower litter weights, and lower placental weights compared to the control group. CONCLUSIONS: HAAR during the entire period of rat pregnancy can reduce maternal body weight gain and lower term placental weight.

Role of L-arginine, a substrate of nitric oxide biosynthesis, on intestinal ischemia-reperfusion in rabbits.

To study whether treatment with L-arginine (ARG), a substrate of nitric oxide biosynthesis, attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rabbits treated with ARG (100 mgxkg(-1), intravenously) or saline solution (SS) prior to I (60 minutes) by occlusion of superior mesenteric artery and/or during R (120 minutes). After I or I/R, 2-cm jejunal segments were isolated and mounted in an organ bath to study of neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained (hematoxylin and eosin) for analysis by optical microscopy. Compared to the sham group, jejunal contractions were similar in I + ARG, but reduced in I + SS, I/R + SS, and I/R + ARG groups. The jejunal enteric nerves were damaged in I + SS, I/R + SS, and I/R + ARG, but not in I + ARG group, suggesting that ARG can attenuate intestinal dysfunctions due to I, but not to R.

Intestinal ischemia-reperfusion is attenuated by treatment with atenolol in rabbits.

To study whether treatment with the beta-blocker atenolol (AT) attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rabbits were treated with AT (1 mg.kg(-1), introvenously) or saline solution (SS) prior to I (60 minutes), which was produced by occlusion of the superior mesenteric artery, and/or R (120 minutes). After I or I/R, 2-cm jejunal segments were mounted in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained hematoxylin and eosin for analysis by optical microscopy. Compared to the sham group, the jejunal contractions were similar in the I + AT and the I/R + AT groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS groups, but not in the I + AT and the I/R + AT. These results suggest that AT may attenuate intestinal dysfunction caused by I and I/R.

Role of adenosine on intestinal ischemia-reperfusion injury in rabbits.

To study if the treatment with adenosine (ADO), an agonist of adenosine receptors, attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), we treated rabbits with ADO (15 mg x kg(-1), intravenously) or saline solution (SS) to I (60 minutes) before occlusion of superior mesenteric artery and/or R (120 min). After I or I/R, isolated jejunal segments (2 cm) were mounted in an organ bath to study nerve-mediated contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained (hematoxylin and eosin) for analysis by optical microscopy. Compared to the sham group, the jejunal contractions were similar in I + ADO, but reduced in I + SS, I/R + SS, and I/R + ADO groups. We concluded that the jejunal enteric nerves were damaged in I + SS, I/R + SS, and I/R + ADO, but not in I + ADO group. These results suggested that ADO attenuated intestinal dysfunction due to I, but not to R.