Ovariectomized Research Articles

Interrogating the estrogen-mediated regulation of adrenocortical Klotho expression using ovariectomized albino rat model exposed to repeated restraint stress.

Reproductive aging is associated with altered stress response and many other menopausal symptoms. Little is known about the adrenal expression of the anti-aging protein Klotho or how it is modulated by estrogen in ovariectomized stressed rats. Fifty-six Wistar female rats were assigned into seven equal groups. Sham-operated (Sham), sham stressed (Sham/STS), ovariectomized (OVR), ovariectomized stressed (OVR/STS), ovariectomized stressed rosiglitazone-treated (OVR/STS/R), ovariectomized stressed estrogen-treated (OVR/STS/E), and ovariectomized stressed estrogen/GW9662 co-treated (OVR/STS/E/GW) groups. All stressed rats were subjected daily to a one-hour restraint stress test for 19days.At the end of the experiment, blood was collected for serum corticosterone (CORT) analysis. Adrenal tissues were obtainedand prepared for polymerase chain reaction (PCR) assay, hematoxylin and eosin (H&E), immunohistochemistry-based identification of Klotho and PPAR-γ, and Oil Red O (ORO) staining. The rise in serum CORT was negligible in the OVR/STS group, in contrast to the Sham/STS group. The limited CORT response in the former group was restored by estrogen and rosiglitazone and blocked by estrogen/GW9226 co-administration. ORO-staining revealed a more evident reduction in the adrenal fat in the OVR/STS group, which was reversed by estrogen and counteracted by GW. Also, there was a comparable expression pattern of Klotho and PPAR-γ in the adrenals. The adrenal Klotho decreased in the OVR/STS group, but was reversed by estrogen treatment. GW9226/estrogen co-treatment interfered with the regulatory effect of estrogen on Klotho. The study suggested modulation of the adrenal Kotho expression by estrogen, in the ovariectomized rats subjected to a restraint stress test. This estrogen-provided adrenal protection might be mediated by PPAR-γ activation.

The hormonal environment and estrogen receptor signaling alters Chlamydia muridarum infection in vivo.

Genital Chlamydia is the most common bacterial sexually transmitted infection in the United States and worldwide. Previous studies indicate that the progression of chlamydial infection is influenced by various factors, including the female sex hormones estrogen and progesterone. Sex hormone levels naturally fluctuate in women throughout their menstrual cycle. Varying concentrations of estrogen and progesterone may impact the progression of chlamydial infection and the host's immune response to Chlamydia. Estrogen signals through estrogen receptors (ERs), ERα and ERβ. These receptors are similar in structure and function, but are differentially expressed in tissues throughout the body, including the genital tract and on cells of the immune system. In this study, we used ovariectomized (OVT) BALB/c mice to investigate the impact of long-term administration of physiologically relevant concentrations of estrogen (E2), progesterone (P4), or a combination of E2/P4 on the progression of and immune response to C. muridarum infection. Additionally, we used ERα and ERβ knockout C57/BL6 mice to determine the how ERs affect chlamydial infection and the resulting immune response. Estrogen exposure prevented C. muridarum infection in vaginally infected OVT mice exposed to E2 alone or in combination with P4, while OVT or Sham mice exposed to hormone free, P4 or depo-medroxyprogesterone acetate shed similar amounts of chlamydiae. The hormonal environment also altered T cell recruitment and IFNϵ production the genital tracts of infected OVT and Sham mice on day 10 post infection. The absence of ERα, but not ERβ, in ER knockout mouse strains significantly changed the timing of C. muridarum infection. ERαKO mice shed significantly more chlamydiae at day 3 post infection and resolved the infection faster than WT or ERβKO animals. At day 9 post infection, flow cytometry showed that ERαKO mice had more T cells present and targeted RNA sequencing revealed increased expression of CD4 and FOXP3, suggesting that ERαKO mice had increased numbers of regulatory T cells compared to ERβKO and WT mice. Mock and chlamydia-infected ERαKO mice also expressed more IFNϵ early during infection. Overall, the data from these studies indicate that sex hormones and their receptors, particularly ERα and ERβ, differentially affect C. muridarum infection in murine models of infection.

Role of the antioxidant pathway in the healing of peptic ulcers induced by ischemia-reperfusion in male and female rats treated with Eugenia punicifolia.

Ischaemia and reperfusion (I/R)-induced gastrointestinal disorders are caused by free radicals, resulting in organ damage and functional disarrangement. This study aimed to investigate the healing effects of hydroalcoholic extracts from the leaves of Eugeniapunicifolia (Kunth) DC. (HEEP) in male and female Wistar rats with I/R-induced peptic injuries, and the role of antioxidants in improving this response. After I/R-induced gastric and duodenal injuries, male and female [intact (INT) and ovariectomized (OVZ)] rats were orally treated with HEEP for 6 days. Biochemical analysis was used to determine the catalase (CAT), superoxide dismutase (SOD), and myeloperoxidase (MPO) activities, as well as malondialdehyde and reduced glutathione levels, to measure the gastric and duodenal healing process. Six days of HEEP treatment significantly decreased the I/R-induced gastric [male (73.68%), INT (52.83%), and OVZ (43.13%)] and duodenal damage [male (57.03%), INT (56.04%), and OVZ (54.83%)] in all groups. In OVZ rats, the healing effect of HEEP occurred because of the increased activity of SOD (2x) and CAT (1.16x) in the gastric mucosa. In the duodenal mucosa of INT rats, the extract reduced MPO (20.83%) activity. The 6-day HEEP treatment improved the healing of I/R-induced peptic ulcer injury, with the system acting differently in males and females. The antioxidant system is an important component of the HEEP activity during post-I/R mucosal recovery. This result revealed the importance of antioxidant compounds in minimizing the severity of I/R-related events.

A high dose of estrogen can improve renal ischemia-reperfusion-induced pulmonary injury in ovariectomized female rats.

Renal ischemia-reperfusion injury (RIRI) as a pathological process induces remote organ injury such as lung complications and it is regulated in a hormone-dependent manner. This study investigates the effect of estrogen on RIR-induced pulmonary injury in ovariectomized (OV) rats. A total of 60 female Wistar rats were divided into six groups: (i) intact sham, (ii) OV sham, (iii) OV sham + estradiol valerate (E), (iv) intact ischemia, (v) OV ischemia, and (vi) OV ischemia + E. Bilateral ischemia was performed for 45min in all groups except sham. Before the ischemia, OV groups received an intramuscular (i.m.) injection of E. After reperfusion, blood samples were collected for serum analysis and kidney and lung tissue were separated for pathological experiment and malondialdehyde (MDA) and nitrite measurement. The left lung was weighed to measure pulmonary edema. Estrogen deficiency caused a greater increase in blood urea nitrogen and creatinine levels during IRI. Ischemia reduced nitrite of serum and lung tissue. The increased level of MDA during ischemia, returned to normal levels via estrogen injection. The severity of renal and lung damage in ischemic groups increased significantly, and estrogen improved this injury. Estrogen as an antioxidant agent can reduce oxidative stress and may improve renal function and ameliorating lung damage caused by RIR.

Differential Expression of Estrogen Receptors in the Hypothalamus Underlies the Bimodal Effects of Estradiol on Luteinizing Hormone Release

Low 17β-estradiol (E2) levels suppress luteinizing hormone (LH) release, while high E2 stimulates an LH surge in the positive-feedback required for ovulation. Kisspeptin (Kp) neurons in the anteroventral periventricular (AVPV) and arcuate (ARC) nuclei of hypothalamus have been implicated in E2 positive- and negative-feedback effects, respectively. However, how E2 differentially regulates these two neuronal populations remains unknown. We investigated whether neurons in the AVPV and ARC are differently responsive to changes in E2 levels and the regulatory role of estrogen receptors (ERs). Ovariectomized (OV) rats received oil or E2 at doses of 4 (OVE-4), 40 (OVE-40), or 80 (OVE-80) µg/kg. Rats on diestrus (DI) and proestrus (PRO) were used as physiological controls. OV rats were also treated with 0.02, 0.2 or 2.0 mg/kg of propyl pyrazole triol (PPT), or 6 mg/kg of diarylpropionitrile (DPN). Serial blood samples were collected for hormonal measurements. Brains were processed for immunohistochemistry and qPCR analyses in the AVPV and ARC. The E2 doses gradually increased plasma E2, with PRO levels being attained in OVE-80 rats. OVE-80 rats displayed a PRO-like LH surge, while LH levels were constantly suppressed in OVE-4 rats. Progesterone receptor (PR) was used as an index of E2 responsiveness. PR expression was increased in the AVPV of PRO and OVE-80 rats, associated with c-Fos expression and occurrence of LH surge. In the ARC, both low and high E2 induced PR expression and reduced the number of Kp-immunoreactive (ir) neurons, consistent with the negative feedback effects on LH. E2 at 4 or 80 µg/kg equally induced PR expression in 90% of ARC Kp-ir neurons. Despite the higher sensitivity to E2 in the ARC, the percentage of neurons expressing ERα was lower in the ARC compared with AVPV. However, Esr1 expression was 2-fold higher in the ARC than in AVPV for low E2 levels, whereas both Esr1 and Esr2 were more expressed in the AVPV under high E2 status. Notably, Esr1/Esr2 ratio was twice as high in the ARC as in the AVPV regardless of E2 levels, suggesting a stronger ERβ inhibition over ERα in the AVPV. Accordingly, ERα selective activation with PPT increased PR in the ARC at the doses of 0.2 and 2.0 mg/kg, reducing plasma LH, while only the highest dose was able to stimulate PR expression in the AVPV. ERβ activation with DPN, in turn, had no effect in OV rats but amplified the induction of AVPV PR and the size of the LH surge in OVE-80 rats. Thus, we provide evidence that ARC and AVPV neurons are responsive to low and high E2 levels, respectively. ARC is 10 times more sensitive to ERα activation than AVPV, whereas ERβ positively modulates AVPV responsiveness to high E2. These differential responses to E2 seem to be related to differences in the relative Esr1 and Esr2 expression in the ARC and AVPV. Our findings suggest that hypothalamic differences in the relative expression of ERs play a key role in the bimodal regulation of LH release by E2.

In vivo protective effect of rosemary ethanol extract on osteoporosis through regulation of osteoclast differentiation and bone resorption activity

Bone is dynamic tissue that is constantly destroyed or resorbed by osteoclasts and then replaced by osteoblasts in physiological process referred to as bone remodeling. In this study, the protective effect of rosemary ethanol extract (REE) on osteoporosis was investigated using RANKL-induced osteoclasts and ovariectomized rats. In animal study, the total of sixty 8 week-old female Spraque-Dawley rats were randomly divided into sham-operated group and four ovariectomized (OVA) groups: OVA, OVA + 17β-estradiol (E2, 50 μg/kg/day) and OVA + REE (125 or 250 mg/kg/day). Daily oral administration of E2 or REE began 3 weeks after surgery and lasted for 12 weeks. REE inhibited the decrease in total BMD and BMC of the femur induced by OVA, which was accompanied by a significant reduction in bone remodeling. The bone turnover markers such as BALP, PICP, OPG, RANKL, TRAP, and ICTP were regulated by REE treatment. In addition, TRAP and bone resorption activity were dose-dependently by REE in RANKL-induced osteoclast differentiation. In conclusion, the protective of REE on osteoporosis can be accomplished by attenuating RANKL-induced osteoclast differentiation and bone resorption activity. These results indicate that REE may utilized as a therapeutic agent for the prevention of bone metabolism-related diseases as osreoporosis

Protective effects of tamoxifen and raloxifene on apoptosis and oxidative stress in the kidney and liver of ovariectomized rats

In the postmenopausal period, women undergo physical and morphological changes that may result in insufficiency and deterioration in physiological functions. It is accepted that oxidative stress is involved in the etiology of postmenopausal changes. It is known that the decrease in ovarian hormones, especially 17β-estradiol (17-β) after menopause induces apoptosis and oxidative stress in many tissues. It is well known that 17-β has an antioxidant role in non-menopausal women. Recently, we observed that the treatments of 17-β, raloxifene (RAL), and tamoxifen (TAM) diminished apoptotic factors, oxidative stress, and mitochondrial membrane depolarization in the brain and dorsal root ganglia of ovariectomized rats. There is no enough information about the effects of triple therapy [17-β, and selective estrogen receptor modulators (TAM and RAL)] effects on liver and kidney tissues. We aimed to investigate the effects of 17-β, TAM, and RAL on apoptosis, cell viability (MTT), and oxidative stress in the kidney and OV+TAM, and OV+RAL. 17-β, TAM, and RAL were subcutaneously given to three groups (OV+17-β, OV+TAM, and OV+RAL) for 14 days after ovariectomy. While kidney and liver cells lipid peroxidation levels were high in the OV group, they were low in the OV+17-β, OV+TAM, and OV+RAL groups. The treatments of 17-β, TAM, and RAL in the groups of OV+17-β, OV+TAM, and OV+RAL increased the glutathione peroxidase (GSH Px) activity and glutathione (GSH) levels in the cells of kidney and liver. In addition, the MTT level of kidney and liver cells was low in the OV group and higher in the OV+17-β, OV+TAM, and OV+RAL groups. The treatments of OV+17-β, OV+TAM, and OV+RAL decreased the apoptosis and ROS levels in kidney and liver cells. In conclusion, we observed that 17-β, TAM, and RAL administrations were beneficial on cell viability (MTT), apoptosis, and ROS levels in the kidney and liver cells of OV rats by modulating antioxidant systems. liver of bilateral ovariectomized (OV) rats. Forty female rats used in the experiment, and they were divided into five groups as control, OV, OV+17-β,

Tamoxifen protective role in ovariectomy related- metabolic disorders in rats

Background: postmenopausal women are more susceptible to insulin resistance. Many studies reported that estrogen (E2) contributes in insulin sensitivity improvement. As a result of postmenopausal estrogen replacement therapy (ERT) hazards, tamoxifen (TAM) as an alternative to estrogen are now applicable. There are no published data distinguishing the effects of TAM on insulin sensitivity in non-diabetic post menopause women. Objectives: Test whether TAM acts as E2 in improving insulin sensitivity in post- menopausal period and to what extent the effect would be similar for both, together with exploring the underlying mechanism. Material & method: Forty female albino rats were divided into 4 groups (10 rats each): sham (SH), ovariectomized (OV), ovariectomized E2 (OVE) treated and ovariectomized TAM (OVT) treated groups. At the end of experiment, blood samples were taken for estimation of fasting blood glucose (FBG), serum concentration of insulin, homeostasis model assessment of insulin resistance (HOMA-IR), lipid parameters and tumour necrosis factor α (TNFα), then adipose tissues were removed for measurement of MDA and SOD. Also, histopathological and immunohistochemical examination of adipose tissue were done. Results: Ovariectomy worsened glycemic state, insulin resistance and lipid profile. TAM was like E2 induced glucose metabolic improvement, decreased insulin resistance alongside with lipid profile improvement. These metabolic changes might assert to oxidative state and inflammatory response improvement accompanying apparent histopathological and immunohistochemical changes on adipose tissue. Conclusion: TAM can counterbalance the metabolic disorders in postmenopausal period and this may improve metabolic disorders as E2 with avoiding the undesired effects of ERT.

Exercise training attenuates diabetes-induced cardiac injury through increasing miR-133a and improving pro-apoptosis/anti-apoptosis balance in ovariectomized rats.

Objective(s):The useful and effective role of exercise program to prevent cardiac tissue apoptosis and fibrosis in ovariectomized type 2 diabetic (T2DM) rats (OVR.D) is well known. The current study aimed to investigate the simultaneous effects of T2DM and swimming plan on the expression of some apoptotic, anti-apoptotic biomarkers and glycogen changes in the cardiac muscle tissue of ovariectomized (OVR) rats.Materials and Methods:Forty rats were randomly sorted into 4 equal categories; sham, OVR, OVR.D and diabetic ovariectomized with an 8 week of swimming plan (OVR.D.E). Lipid profile and miR-133, Bcl-2, Bax, caspase-3 and caspase-8 levels were evaluated in the cardiac tissue.Results:Ovariectomy significantly (P-value<0.05) increased cholesterol, triglyceride, LDL, Bax, caspase-3, caspase-8 and decreased (P-value<0.05) HDL, miR-133, Bcl-2 in the cardiac tissue and a further reduction in the expression of miR-133, Bcl-2 and an enhancement in Bax, caspase-3 and caspase-8 in OVR.D rats was observed (P-value<0.01). However, exercise training significantly reversed all the measured parameters (P-value<0.05). Also, exercise training improved abnormal tissue structure, fragmentation and irregular form of glycogen granules in the OVR.D.E compared to OVR and OVR.D animals.Conclusion:Exercise training could prevent the cardiac disturbance, enhance the expression of anti-apoptotic markers and decrease apoptotic biomarkers in the hearts of OVR.D animals. Therefore, based on the findings of this study suggested using the exercise’s beneficial effects for prevention of the cardiac cell death in OVR.D animals.

The Effect of Testosterone and Estradiol on Renal Function Markers in Two Protocols of Cisplatin Induced Nephrotoxicity Models in Surgically Orchiectomized and Ovariectomized Rats

Background: The major side effect of cisplatin (CP) therapy in patients with cancer is nephrotoxicity, which limits the treatment. In two protocols of CP treatments, we tested 3 weeks of hormone therapy against CP induced nephrotoxicity in bilateral orchiectomized (OR) and ovariectomized (OV) rats. Methods: A total of 101 OR and OV rats were subjected to receive 3 weeks of testosterone (Ts, 10 mg/kg/week) and estradiol (Es, 250 µg/kg/week), respectively, followed by two protocols of CP therapies; continuous (divided) doses (3 mg/kg/day for period of 5 days) as protocol 1 and single dose (7.5 mg/kg) as protocol 2. The measurements were performed by the end of the 4th week. Results: CP increased the serum levels of blood urea nitrogen (BUN) and creatinine (Cr) in both OR and OV rats, which were related to the protocols of CP treatments. Es (not Ts) in protocol 2 attenuated the serum levels of BUN and Cr. Ts significantly increased body weight loss in protocol 1 compared with control group (P < 0.05). Es did not attenuate kidney tissue damage score (KTDS) in protocol 1 treated animal, but KTDS was decreased by Es in protocol 2 treated Rats. Hormone replacement therapy did not alter Cr clearance compared with control group. Conclusions: It seems that hormone therapy could not protect the kidney against CP induced nephrotoxicity.

Can the gastric healing effect of Eugenia punicifolia be the same in male and female rats?

Ethnopharmacological relevanceEugenia punicifolia (Kunth) DC. (Myrtaceae), an Amazonian medicinal plant known as “pedra-ume-caá,” is popularly used as a natural remedy for inflammation, wounds, infections, diabetes, fever, and flu. Its anti-inflammatory, antinociceptive, and gastroprotective effects have already been characterized. We evaluated the gastric healing effect of the hydroalcoholic extract of the leaves of E. punicifolia (HEEP) in male and female Wistar rats against nonsteroidal anti-inflammatory drugs (NSAIDs) and ethanol. Materials and methodsThe healing effect of HEEP on the gastric mucosa of adult male and female Wistar rats was measured after the chronic application of aggressive factors such as NSAIDs or 80% ethanol. Male, and intact and ovariectomized (OVZ) female rats were treated with HEEP for two days (NSAIDs) or one, two, four, and six days (80% ethanol). The stomachs were analyzed macroscopically for ulcerative lesions (mm2), and the healing process was measured using biochemical analysis with anti-inflammatory and antioxidant parameters. ResultsMacroscopic evaluation of the gastric mucosa showed that gastric lesions induced by NSAIDs were significantly healed (66%) and pro-inflammatory interleukin 5 cytokine level was decreased after two-day oral treatment with HEEP compared with those in the negative control group (p < 0.05). However, the gastric lesions induced by NSAIDs did not heal in HEEP-treated female rats (p > 0.05). In addition, four-day treatment with HEEP significantly healed the gastric lesions induced by ethanol in male and female rats (63% and 78%, respectively) compared to those of the negative control group (p < 0.05). However, the OVZ group required six days of HEEP treatment to heal gastric ulcers (67% compared to the control group). HEEP exerts the healing effect against ethanol by significantly reducing neutrophil infiltration into the gastric mucosa by decreasing myeloperoxidase activity in male and OVZ rats after four and six days of treatment, respectively (p < 0.05). Four-day treatment with HEEP also increased the level of a non-enzymatic antioxidant, reduced glutathione in intact females compared to that of the negative control group (p < 0.05). ConclusionThese findings indicated that HEEP was effective in promoting the healing of gastric ulcers induced by NSAIDs or ethanol. The gastric healing effects of this extract could be affected by female sex hormone interference; in future, comprehensive studies should be performed by considering sex differences.

Interaction of Sex Hormones and the Renin-Angiotensin System in Ovariectomized Rats Subjected to Ischemia-Reperfusion Induction.

Backgrounds:Ischemia-reperfusion (IR) injuries occur in a variety of clinical conditions, which lead to kidney damage. Most of the tissue damages after IR are due to the activation of the renin–angiotensin system (RAS). Hence, in this study, the interaction of sex hormones and RAS in ovariectomized (OV) rats subjected to IR induction has been studied.Materials and Methods:The animals were divided into different groups. Groups 1 (OV + E, OV rat + estradiol) and 2 (OV rat) each one consisted of three separate IR-induced subgroups treated with losartan, angiotensin 1–7 (Ang 1–7), and their combination, Group 3, as control and Group 4, as sham. Next, 72 h after IR, blood samples were collected, the right kidneys were homogenized, and left kidneys were fixed in 10% formalin.Results:Findings show that serum blood urea nitrogen, creatinine, and kidney tissue damage score levels increased significantly with induction of IR (P < 0.05). Mean serum levels of these factors in OV + E groups are higher than those of the OV. The presence or absence of estradiol did not affect the levels of antioxidants in the different groups receiving Los, Ang 1–7, and their combination. Los, Ang 1–7, and their combination reduced serum and kidney malondialdehyde levels in both OV and OV + E groups.Conclusion:Estrogen not only fails to improve renal functioning but it can also exacerbate it. While the treatments used in this study, in the absence of estradiol, it had a better effect on kidney damages and improved its functions.

Respiratory muscle blood flow during exercise: Effects of sex and ovarian cycle.

Sex and ovarian cycle have been speculated to modify respiratory muscle blood flow control during exercise, but the findings are inconclusive. We tested the hypotheses that females would have higher respiratory muscle blood flow and vascular conductance (VC) compared with males during exercise and that this difference would be accentuated in proestrus vs. ovariectomized (OVA) females. Mean arterial pressure (carotid artery catheter) and respiratory muscle blood flow (radiolabeled microspheres) were measured during moderate-intensity (24 m/min, 10% grade) exercise in male (n = 9), female (n = 9), and OVA female (n = 7) rats and near-maximal (60 m/min, 5% grade) exercise in male (n = 5) and female (n = 7) rats. At rest, diaphragm, intercostal, and transversus abdominis blood flow were not different (P = 0.33) among groups. During moderate-intensity exercise, diaphragm (M: 124 ± 16; F: 140 ± 14; OVA: 140 ± 20 ml·min-1·100 g-1), intercostal (M: 33 ± 5; F: 34 ± 5; OVA: 30 ± 5 ml·min-1·100 g-1), and transversus abdominis blood flow (M: 24 ± 4; F: 35 ± 7; OVA: 35 ± 9 ml·min-1·100 g-1) significantly increased in all groups compared with rest but were not different (P = 0.12) among groups. From rest to moderate-intensity exercise, diaphragm (P < 0.03) and transversus abdominis (P < 0.04) VC increased in all groups, whereas intercostal VC increased only for males and females (P = 0.01). No differences (P > 0.13) existed in VC among groups. During near-maximal exercise, diaphragm (M: 304 ± 62; F: 283 ± 17 ml·min-1·100 g-1), intercostal (M: 29 ± 8; F: 40 ± 6 ml·min-1·100 g-1), and transversus abdominis (M: 85 ± 14; F: 86 ± 9 ml·min-1·100 g-1) blood flow and VC were not different (P > 0.27) between males and females. These data demonstrate that respiratory muscle blood flow and vascular conductance at rest and during exercise are not affected by sex or ovarian cycle in rats.NEW & NOTEWORTHY It has been proposed that sex and ovarian cycle modulate respiratory muscle blood flow control during exercise. We demonstrate herein that neither sex nor ovarian cycle influences respiratory muscle blood flow or vascular conductance at rest or during exercise in rats.

CARDIOPROTECTIVE PROPERTIES OF PROGESTINES: INFLUENCE OF DROSPIRENONE ON MYOCARD IN EXPERIMENTAL HEART FAILURE

Aim. To assess the influence of synthetic progesterone — drospirenone, on remodeling of the left ventricle myocardium (LV) in ovariectomized (OE) female rats under circumstances of experimental heart failure (EHF). Material and methods. The study was done on 25 female Wistar rats, mass 260-300 g. Twenty animals (in 2 months after bilateral ovariectomy) underwent modeling of EHF by subcutaneous load of 0,1% mesaton solution for 14 days with following swimming to profound exhaustion. Four rats were removed on 14th day of EHF. Sixteen experimental animals with EHF were selected to 3 groups: 10 underwent 14 days subcutaneous load of drospirenon (Sigma-Aldrich, USA), dose 2 mg/kg (n=5) and 0,5 mg/kg (n=5), 6 were being loaded saline 0,2 mL daily. On 28th day the animals were removed from the experiment. With light microscopy method, immune cytochemistry, morphometry the LV myocardium was investigated. Results . In OE rodents on the 14th day of EHF there was clear and significant heteromorphism of contractile cardiomyocytes (CMC) with the signs of hypertrophy and dystrophy; increase of the volume density (VD) of stroma, reorganized extracellular matrix (EM), expression of metalloproteases-2,9 (MMP-2,9) and tissue inhibitor of metalloproteases-1 (TIMP-1), CMC with apoptosis. After remodeling of EHF at 28th day in myocardium there was further increase of CMC number with significantly changed morphology and tinctorial properties, degradation of EM components. In rats receiving 14 days drospirenon, regardless of dosage, there was regression of pathological changes, decrease of CMC hypertrophy grade, as the nuclei, decrease of CMC with the signs of apoptosis, and stabilized EM components. Conclusion. The cardioprotective properties of drospirenon are discussed, that even in minimal therapeutic concentrations facilitates structural and functional rehabilitation of myocardium under conditions of gonade hormones deficiency and EHF.

Features of the Action of Combined Administration of NAN-190 and Ketanserin with Low-Dose 17β-Estradiol on Depression-Like Behavior in Prenatally Stressed Rats

The aim of the present work was to compare the effects of blockade of 5-HT1A or 5-HT2A/2C serotonin receptors on depression-like behavior in adult female rats with experimental estrogen deficiency whose mothers had been subjected to prenatal stress during pregnancy. Two weeks after removal of the ovaries, ovariectomized (OE) prenatally stressed female rats received chronic administration of the 5-HT1A serotonin receptor antagonist NAN-190 (0.1 mg/kg, i.p.) or the 5-HT2A/2C serotonin receptor antagonist ketanserin (0.1 mg/kg, i.p.) alone or in combination with a low dose of 17β-estradiol (0.5 μg/rat, s.c.) for 14 days before behavior tests started and then until tests were completed. The behavioral methods used were the Porsolt test and the open field test. The results showed that chronic administration of NAN-190 to OE prenatally stressed females led to a prodepressive effect, while the combination of NAN-190 with low-dose 17β-estradiol, conversely, had an antidepressant effect in the Porsolt test. In the open field test, these two experimental groups of rats showed decreases in the amounts of grooming reactions, vertical motor activity, and exploratory activity. Administration of ketanserin to OE prenatally stressed females produced an antidepressant effect, as compared with control animals. However, combined administration of ketanserin and low-dose 17β-estradiol to OE prenatally stressed females had no positive effect on the behavior of the animals in the Porsolt test.

In vitro and In vivo Protective Effect of Artemisia capillaris Extract on Osteoporosis through Regulation of Osteoclast Differentiation and Bone Resorption Activity

Bone is dynamic tissue that is constantly destroyed or resorbed by osteoclasts and then replaced by osteoblasts in physiological process referred to as bone remodeling. In this study, the protective effect of Artemisia capillaris extract (ACE) on osteoporosis was investigated using RANKL‐induced osteoclasts and ovariectomized rats. In animal study, The total of sixty 8 week‐old female Spraque‐Dawley rats were randomly divided into sham‐operated group and four ovariectomized (OVA) groups: OVA, OVA + 17β‐estradiol (E2, 50 μg/kg/day) and OVA + ACE (125 or 250 mg/kg/day). Daily oral administration of E2 or ACE began 3 weeks after surgery and lasted for 12 weeks. ACE inhibited the decrease in total BMD and BMC of the femur induced by OVA, which was accompanied by a significant reduction in bone remodeling. The bone turnover markers such as BALP, PICP, OPG, RANKL, TRAP, and ICTP were regulated by ACE treatment. In addition, the underlying mechanism of anti‐osteoporotic effect of ACE was studied using scoparone, its major bioactive compound. The TRAP and bone resorption activity were dose‐dependently by scoparone in RANKL‐induced osteoclast differentiation. The suppressive effect of scoparone on RANKL‐induced osteoclast differentiation was executed by down‐regulating ROS production through NADPH oxidase 1 and mitochondria and by scavenging generated ROS. In conclusion, the protective of ACE on osteoporosis can be accomplished by attenuating RANKL‐induced osteoclast differentiation and bone resorption activity. These results indicate that ACE may utilized as a therapeutic agent for the prevention of bone metabolism‐related diseases.

Effects of an Agonist and an Antagonist of Nα7-Cholinoreceptors on Active Learning and Sex Hormone Levels in Ovariectomized Female Rats

The effects of combined administration of an agonist and an antagonist of Nα7-cholinoreceptors with a low dose of 17β-estradiol on the dynamics of the acquisition and extinction of an active avoidance reflex and behavior in the open field test, as well as on the levels of trophic and peripheral sex hormones, in ovariectomized (OE) female rats. The Nα7-cholinoreceptor agonist RJR-2403 (1.0 mg, i.p.) and the antagonist of these receptors mecamylamine (1.0 mg/kg, i.p.) were given chronically (14 days) alone or combined with a low dose of 17β-estradiol (0.5 μg per animal, s.c.) in female rats after ovariectomy. RJR-2403 in combination with low-dose 17β-estradiol completely restored the dynamics of active learning and increased investigative activity and grooming reactions in the open field test in OE females. This group of rats showed decreases in serum follitropin (FSH) and lutropin (LH) levels, along with increases in the estradiol level. Conversely, mecamylamine given alone or in combination with a low dose of 17β-estradiol had no significant effect on the nature of active learning or behavior in the open field test in OE females. The results obtained here provide evidence of the positive effects of stimulating Nα7-cholinoreceptors on the background of low-dose 17β-estradiol on active learning and on the concentrations of gonadotropins and estradiol in conditions of estrogen deficiency.

Grape powder supplementation improves blood pressure, anxiety‐like behavior and learning and memory function in ovariectomized rats.

Estrogen is of prime importance to normal brain function; and its depletion at menopause may account, at least in part, for cognitive decline as well as hypertension. Here, we examined the effect of grape powder treatment on anxiety‐like behavior, learning and memory impairment and blood pressure in ovariectomized (OVR) rats. Four groups of Wistar female rats were used. Group 1 and 2 included controls for sham and sham‐grape powder treated, group 3 was OVR, and group 4 was OVR and grape powder treated for 2 weeks. At the end of the 2 weeks, body weights, food and water intake, blood pressure were recorded, anxiety‐like behavior (open‐field and light‐dark) and learning‐memory (radial water maze) tests were conducted. We observed a significant increase in systolic and diastolic blood pressure in OVR rats as compared to sham‐controls. Furthermore, ovariectomy increased anxiety‐like behavior and caused learning and memory impairment in rats as compared to the sham‐control group. Interestingly, supplementation with grape powder to OVR rats for 2 weeks was marked with restoration of both systolic and diastolic blood pressure, improvement in the anxiety‐like behavior and learning and memory function. This supports our hypothesis that grape powder may be an attractive target for estrogen replacement therapy. Oxidative stress data points towards interesting mechanistic clues to these observations.Grant Support: NIH R15 G103327

Protective effects of estrogen on chronic ocular hypertension-related rabbit retinal damages

Objective To investigate the protective effects of estrogen on rabbit retinal damages induced by chronic ocular hypertension. Methods A total of 18 white New Zealand female rabbits were randomly divided into ovariectomized (OV) group and sham OV (SOV) group. Bilateral ovaries were remove in OV group while only the adipose tissue around ovarian were remove in SOV group. Chronic ocular hypertension was induced by anterior chamber injection of carbomer. Retinal cell apoptosis was measured by terminal deoxynucteotidyl transferase-mediated dUTP nick end labeling (TUNEL), the expression of bcl-2,bax were detected by immunohistochemistry. The images were captured under microscope and analyzed with computer-image-analysis system. Results Four, six and eight weeks after ocular hypertension modeling,the OV retinas have less retinal ganglion cells, thinner optic nerve fiber layer and inner nuclear layer and more TUNEL positive cells (t = 3. 285, 4. 012, 3. 624; P< 0.01). The OV retinas also have less bcl-2 expression (t=4. 256,3. 867,3. 459;P<0. 01), more bax positive cells (t=3. 211,3. 625,3. 253;P<0. 01).Bcl-2 expression was negatively correlated with TUNEL positive cells indicating bcl-2 can inhibit apoptosis.Bax expression was positively correlated with TUNEL positive cells indicating bax induce apoptosis.Conclusion Estrogen has a neuroprotection role to rabbit retina under chronic ocular hypertension by reducing apoptosis. Key words: Estrogens/physiology; Retinal ganglion cells; Apoptosis; Bcl-2-associated X protein; Animal experimentation

Influence of Reproductive Season upon Plasma Biochemistry Values in Green Iguanas

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