Decrease In Uterine Weight Research Articles

Safety of Oral Carica papaya L. Leaf 10% Ethanolic Extract for Acute and Chronic Toxicity Tests in Sprague Dawley Rats.

Carica papaya L. leaves, traditionally utilized in dietary supplements and pharmaceuticals, exhibit a broad spectrum of potentially therapeutic properties, including anti-inflammatory, antimalarial, and wound healing properties. This study examined the acute and chronic toxicity of 10% ethanolic-extracted C. papaya leaf in Sprague Dawley rats. The acute toxicity assessment was a single oral dose of 5000 mg/kg body weight, while the chronic toxicity assessment included daily oral doses of 100, 400, 1000, and 5000 mg/kg over 180 days. Systematic monitoring covered a range of physiological and behavioral parameters, including body and organ weights. End-point evaluations encompassed hematological and biochemical analyses, along with gross and histopathological examinations of internal organs. Findings revealed no acute toxicity in the C. papaya leaf extract group, although a significant decrease in uterine weight was observed without accompanying histopathology abnormalities. In the chronic toxicity assessment, no statistically significant differences between the control and the C. papaya leaf extract groups were detected across multiple measures, including behavioral, physiological, and hematological indices. Importantly, histopathological examination corroborated the absence of any tissue abnormalities. The study results indicate that C. papaya leaf extract exhibited no adverse effects on the rats during the 180-day oral administration period, affirming its potential safety for prolonged usage.

Endometrial stromal PRMT5 plays a crucial role in decidualization by regulating NF-κB signaling in endometriosis

Decidualization is a prerequisite for successful embryo implantation, in which elongated fibroblast-like endometrial stromal cells differentiate into more rounded decidual cells. Accumulating evidence has stressed the important role of the defective eutopic endometrium in infertility in endometriosis patients. However, the role of arginine methylation in the process of physiological decidualization and pathological decidualization defects is not clear. Here, we observed that the expression level of PRMT5, the main type II PRMT, was decreased in the endometrium of endometriosis patients, predominantly in stromal cells. Compared with the undecidualized state, PRMT5 was increased in the stromal cells of normal secretory endometrium in humans and in the decidua of normal pregnant mice or mice with artificially induced decidualization. The inhibition of PRMT5 resulted in a significant decrease in uterine weight and decidualization-related regulator expression, including FOXO1, HOXA10 and WNT4, in mice and IGFBP1 and prolactin levels in human endometrial stromal cells. Transcriptome analysis showed that decreased PRMT5 activity led to NF-κB signaling activation by inducing p65 translocation to the nucleus, which was also observed in endometriosis patients. Finally, overexpression of PRMT5 rescued the defective expression of IGFBP1 and prolactin in primary endometrial stromal cells from endometriosis patients. Our results indicate that promotion of PRMT5 may provide novel therapeutic strategies for the treatment of decidualization defects in infertile women, such as those with endometriosis.

EGCG exposure during pregnancy affects uterine histomorphology in F1 female mice and the underlying mechanisms

Although epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, has been shown to have many benefits, the effect of EGCG exposure in utero on adult uterine development is unclear. In this study, pregnant C57BL/6 mice were exposed to 1 mg/kg body weight (bw) EGCG dissolved in drinking water from gestational days 0.5–16.5. A significant decrease in uterine weight was observed in the adult female mice, accompanied by uterine atrophy, inflammation, and fibrosis in the endometrium. Uterine atrophy was attributed to the thinning of the endometrial stromal layer and a significant reduction in endometrial cell proliferation. The expression levels of related proteins in the NF-κB and RAF/MEK/ERK signaling pathways were significantly increased, which might be responsible for the occurrence of inflammation. Activation of the transforming growth factor beta (TGF-β1)/Smad signaling pathway might be involved in the development of endometrial fibrosis. The changes in the expression of estrogen receptor α, β (ERα, ERβ), progesterone receptor (PGR), and androgen receptor (AR) might lead to changes in the aforementioned signaling pathways. The promoter region methylation level of Esr2 was increased, and the expression of DNMT3A was evaluated. Our study indicates a risk of EGCG intake during pregnancy affecting uterine development in offspring.

Protection against Osteoporosis by Fermented Mulberry Vinegar Supplementation via Inhibiting Osteoclastic Activity in Ovariectomized Rats and Osteoclastic Cells

Menopause increases the osteoporosis risk, to which phytoestrogen intake can be beneficial. This study hypothesized that mulberry vinegar had a preventive effect on osteoporosis by decreasing osteoclastic activity. The hypothesis was tested in ovariectomized (OVX) rats and RANKL-differentiated osteoclast cells. OVX rats were given 0(OVX-CON), 0.5(OVX-MVL), 1(OVX-MVM), and 2(OVX-MVH) fermented mulberry vinegar (MV) mL/kg body weight (BW) daily for 12 weeks. Sham-operated rats had no MV supplementation (Normal-CON). The osteoporosis-related biomarkers were measured, and Micro-CT determined the bone mass of the femur. RANKL-differentiated Raw 264.7 cells were treated with MV (0–100 μg/mL). The cell viability, osteoporosis-related mRNA expression, and protein contents were measured. MV contained Acetobacter pasteurianus (7.31 log CFU/mL), citric acid (106 mg/mL), lactic acid (19.2 mg/mL), acetic acid (15.0 mg/mL), and rutin (0.36 mg/mL). OVX-MVM elevated the serum 17β-estradiol concentration similar to the Normal-CON group, but it did not prevent the decrease in uterine weight. OVX-MVM prevented the increase in osteoclastic-related parameters, including cathepsin K(CtsK), receptor activator of NF-κB ligand (RANKL), and tartrate-resistant acid phosphatase (TRAP) in the circulation. OVX-MVH also lowered C-telopeptide of type Ⅰ collagen as much as the Normal-CON group (p < 0.05). By contrast, OVX-MVH increased the serum osteoprotegerin concentration, an inhibitor of osteoclasts, better than the Normal-CON group (p < 0.05). These changes were integrated to alter the bone mineral density (BMD) in Micro-CT analysis: OVX-MVM and OVX-MVH prevented BMD decrease after OVX as much as the Normal-CON. In RANKL-differentiated osteoclast cells, the MV treatment for 24 and 48 h decreased RANKL-induced differentiation in osteoclast cells dose-dependently up to 100 µg/mL. Its decrease was related to inhibiting the TRAP activity and reducing TRAP-positive multinucleated cells during the five-day administration of RANKL. MV treatments also decreased mRNA expression of osteoclast-related genes (TRAP, Ctsk, OSCAR, and NFATc1). MV suppressed the protein contents of NFATc1 and c-FOS-related osteoclast. In conclusion, MV intake (1 mg/kg bw) protected against BMD loss mainly by inhibiting the osteoclastic activity (RANKL/RANK/TRAP) in OVX rats. MV may develop as a functional food for anti-osteoporosis in menopausal women.

GnRHa Before Single-Port Laparoscopic Hysterectomy in a Large Barrel-Shaped Uterus.

Background and Objectives:Laparoscopic hysterectomy for a large barrel-shaped uterus is difficult. We assessed the feasibility of single-port laparoscopic hysterectomy in a large barrel-shaped uterus after gonadotropin-releasing hormone agonist (GnRHa).Methods:We retrospectively reviewed 39 patients with a large barrel-shaped uterus who were treated with GnRHa (leuprolide acetate) before single-port laparoscopic hysterectomy. During the same period, 134 patients without GnRHa pretreatment were included as control subjects.Results:Patients with GnRHa treatment had an average increase in hemoglobin of 3.0 mg/dL and a decrease in uterine weight of 330.9 g (40.1%). Ancillary ports were required in 2 patients in the treatment group and none in the control group. There were no differences in uterine weights, operative time, and estimated blood loss in the 2 groups of patients. The estimated average operative time was shortened by 34 min after GnRHa treatment. However, bladder and ureter injuries were marginally higher (10.3% versus 2.2%) and days of hospital stay (3.7 versus 3.1) were significantly longer in the treatment group compared with controls. Complication rates were correlated with previous operative history, pelvic adhesion, and larger uterine weight but not with GnRHa treatment and operative sequence.Conclusions:GnRHa pretreatment in patients with a large barrel-shaped uterus during SPH is feasible with shortened operative time. However, the higher complication rates in these patients suggest that a weight-reduced barrel-shaped uterus that is achieved with GnRHa treatment could still be difficult and should be handled in cautious.

Design, synthesis, estrogenic and antiestrogenic activities of some triarylpyrazole derivatives

New triarylpyrazole derivatives, substituted with basic side chain, polar group or heterocyclic ring were designed and synthesized. Nineteen compounds were tested for their in vivo uterotrophic activity. Animals treated with compounds 9, 15a, 15c, 19a, 19f, 20a, and 21b showed pronounced increase in uterine weight. It is worth mentioning that compound 19f was more active than estradiol as an estrogenic compound as evidenced by the increased dry uterine weight. Additionally, compound 19a produced 128.25% increase in dry uterine weight relative to estradiol. On the other hand, eight compounds were screened for their in vivo antiuterotrophic activity. Animals treated with compounds 5e, 5f, 8, and 13b showed pronounced decrease in uterine weight. The highest antiuterotrophic effect was observed in mice receiving compound 13b, which was as potent as the positive control, tamoxifen as evident by the decrease in the uterine wet weight.

Toxicity assessment of molindone hydrochloride, a dopamine D2/D5 receptor antagonist in juvenile and adult rats

Neuroleptic drug molindone hydrochloride is a dopamine D2/D5 receptor antagonist and it is in late stage development for the treatment of impulsive aggression in children and adolescents who have attention deficient/hyperactivity disorder (ADHD). This new indication for this drug would expand the target population to include younger patients, and therefore, toxicity assessments in juvenile animals were undertaken in order to determine susceptibility differences, if any, between this age group and the adult rats. Adult rats were administered molindone by oral gavage for 13 weeks at dose levels of 0, 5, 20, or 60 mg/kg-bw/day. Juvenile rats were dosed for 8 weeks by oral gavage at dose levels of 0, 5, 25, 50, or 75 mg/kg-bw/day. Standard toxicological assessments were made using relevant study designs in consultation with FDA. Treatment-related elevation in serum cholesterol and triglycerides and decreases in glucose levels were observed in both the age groups. Organ weight changes included increases in liver, adrenal gland and seminal vesicles/prostate weights. Decreases in uterine weights were also observed in adult females exposed to the top two doses with sufficient exposure. In juveniles, sexual maturity parameters secondary to decreased body weights were observed, but, were reversed. In conclusion, the adverse effects noted in reproductive tissues of adults were attributed to hyperprolactinemia and these changes were not considered to be relevant to humans due to species differences in hormonal regulation of reproduction. On the whole, there were no remarkable differences in the toxicity profile of the drug between the two age groups.

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Honey has antimicrobial, antitumor, antioxidant, and anti-inflammatory effects. However, there have been few studies regarding the effects of manuka honey on bone metabolism and gut microflora. This study investigated the effects of manuka honey combined with α-cyclodextrin, Manuka Honey with CyclopowerTM (MHCP) on bone metabolism and caecal bacterial contents in ovariectomized (OVX) mice. Seven-week-old female Balb/c-strain mice were divided into four groups: sham-operated (sham) group, OVX group, and OVX mice that were fed a diet containing 5% or 10% (w/w) MHCP. After 9 weeks, the mice were sacrificed, and serum, uterus, caecum, and femur samples were obtained. Successful removal of the ovaries and induction of the osteoporotic process in OVX mice were demonstrated by a significant decrease in uterine weight and a significant increase in receptor activator of NF-κB ligand (RANKL) mRNA expression of the femur, compared to sham, respectively. Compared to the OVX group, MHCP reduced serum C-terminal telopeptide of type Ι collagen concentration as well as RANKL and nuclear factor of activated T-cells c1 (NFATc1) mRNA expression of the femur. Furthermore, MHCP increased caecal bifidobacteria and bacteroides contents. These results suggest that the MHCP expressed prebiotic effects, which might reduce bone resorption in OVX mice.

Non-Nuclear–Initiated Actions of the Estrogen Receptor Protect Cortical Bone Mass

Extensive evidence has suggested that at least some of the effects of estrogens on bone are mediated via extranuclear estrogen receptor α signaling. However, definitive proof for this contention and the extent to which such effects may contribute to the overall protective effects of estrogens on bone maintenance have remained elusive. Here, we investigated the ability of a 17β-estradiol (E2) dendrimer conjugate (EDC), incapable of stimulating nuclear-initiated actions of estrogen receptor α, to prevent the effects of ovariectomy (OVX) on the murine skeleton. We report that EDC was as potent as an equimolar dose of E2 in preventing bone loss in the cortical compartment that represents 80% of the entire skeleton, but was ineffective on cancellous bone. In contrast, E2 was effective in both compartments. Consistent with its effect on cortical bone mass, EDC partially prevented the loss of both vertebral and femoral strength. In addition, EDC, as did E2, prevented the OVX-induced increase in osteoclastogenesis, osteoblastogenesis, and oxidative stress. Nonetheless, the OVX-induced decrease in uterine weight was unaltered by EDC but was restored by E2. These results demonstrate that the protection of cortical bone mass by estrogens is mediated, at least in part, via a mechanism that is distinct from the classic mechanism of estrogen action on reproductive organs.

Anti-osteoporotic activity of methanolic extract of an Indian herbal formula NR/CAL/06 in ovariectomized rats

The present study was aimed to evaluate the anti-osteoporotic activity of methanolic extract of NR/CAL/06 in ovariectomized (OVX) rats. Bilateral ovariectomy was performed in female Sprague-Dawley rats under aseptic conditions and the rats were divided into five groups (n=10). Two different doses of methanolic extract of NR/CAL/06 (200 and 400 mg/kg, per oral (p.o.)) were evaluated for anti-osteoporotic activity and raloxifene (5.4 mg/kg, p.o.) was used as a reference standard. Treatment was given for 90 d. Anti-osteoporotic potential of NR/CAL/06 was evaluated based on various parameters, namely, body weight, organ weight, bone weight, bone mineral content, bone strength, calcium and phosphorus in serum and urine, and serum alkaline phosphatase (ALP). External diameter, length and thickness of the femur bone were measured by using scanning electron microscopy (SEM). The bilateral ovariectomy in rats resulted in decreased bone strength, bone mineral content and bone weight. The SEM images showed porous, perforated and disintegrated femur bone architecture and decreases in bone length and thickness in OVX rats. These changes were associated with elevated serum levels of calcium, phosphorus and ALP. Increases in body weight and adipose weight and a decrease in uterine weight were also observed and the changes were highly significant when compared with the sham-control group. Treatment with methanolic extract of NR/CAL/06 (200 and 400 mg/kg, p.o.) for 90 d dose-dependently restored the ovariectomy-induced alterations in bone weight, bone mineral content, bone strength, serum calcium, phosphorus and ALP, body weight and adipose weight nearly to normal levels. Furthermore, the SEM images of the femur bones of NR/CAL/06 (200 and 400 mg/kg, p.o.)-treated rats showed reduced pore formation and improved bone compactness compared with the OVX-control group. These findings suggest that the methanolic extract of NR/CAL/06 possesses significant anti-osteoporotic activity and may be useful in the treatment of osteoporosis.

Cardioprotective effects of aqueous Schizandra chinensis fruit extract on ovariectomized and balloon-induced carotid artery injury rat models: Effects on serum lipid profiles and blood pressure

The fruit from Schizandra chinensis, a member of the Magnoliaceae family, has been used to treat menopause-related symptoms. We have previously reported that an aqueous extract of Schizandra chinensis fruit (ScEx) caused vascular relaxation via the production of endothelial nitric oxide. Estrogen-like molecules are known to play a protective role in cardiovascular diseases through several mechanisms, but the cardioprotective effects of ScEx have not been clearly demonstrated. Therefore, we investigated the vasculoprotective effects of ScEx on ovariectomized (OVX) and balloon-induced carotid artery injury rat models. An aqueous extract of Schizandra chinensis (ScEx) was examined for its cardioprotective effects. To test the arterial response to injury, we applied the balloon-induced carotid artery model to OVX Sprague-Dawley (SD) rats. Rats were subcutaneously administered vehicle, 17β-estradiol (E2; 0.02 or 0.2mg/kg/day), or ScEx (0.2 or 2.0mg/kg/day) over the course of the study. Vessel morphology was assessed two weeks after injury. To identify the cardioprotective effects after ScEx treatment, we measured serum lipid profiles and blood pressure levels in the OVX- and sham-operated normotensive and spontaneously hypertensive rats (SHR). Serum lipid profiles were measured in OVX rats after five weeks of treatment with vehicle, E2 (0.5mg/kg/day), or ScEx (0.5 or 5.0mg/kg/day). Tail systolic blood pressure in OVX SHR was measured weekly. In the balloon-induced carotid artery injury model, treatment with E2 (0.2mg/kg/day) or ScEx (2.0mg/kg/day) reduced the intimal area and the intima-to-media ratio compared to control animals. Injection of ScEx or E2 reduced body weight gain but did not inhibit the decrease in uterine weight. Treatment with ScEx (5.0mg/kg/day) or E2 (0.5mg/kg/day) in OVX SD rats reduced total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), TC/high-density lipoprotein cholesterol (HDL-C), and TC-(HDL-C)/HDL-C compared to control animals. In OVX rats, treatment with ScEx or E2 also significantly reduced LDL-C compared with the OVX control rats, and systolic blood pressure was significantly attenuated compared to OVX control and the sham control rats. ScEx treatment restored endothelial function in rats that underwent balloon-induced carotid artery injury, and it reduced serum cholesterol levels in OVX rats. Similar to E2, ScEx exhibited hypotensive effects in OVX SHR. Therefore, ScEx and E2 exhibited similar cardioprotective effects, thereby suggesting that ScEx is a potential candidate to replace estradiol in the prevention and treatment of cardiovascular diseases.

Pharmacological profile of MEN 11066, a novel potent and selective aromatase inhibitor

MEN 11066 is a new non-steroidal compound which potently inhibits human placenta ( K i=0.5 nM) and rat ovarian ( K i=0.2 nM) aromatase in vitro. In vivo, a single oral dose of 0.3 mg kg −1 significantly decreased uterus weight in immature rats after stimulation of uterus growth by androstenedione. MEN 11066 reduced in a dose-dependent manner plasma estradiol levels in adult female rats treated with pregnant mare serum gonadotropin (PMSG). After 2 weeks of repeated daily treatment in adult rats, a significant decrease in uterine weight was observed together with a 65% decrease in plasma estradiol, whereas plasma levels of testosterone, progesterone, aldosterone, corticosterone, cholesterol, LH and FSH were not affected. The lack of any effect by MEN 11066 on adrenal steroids was confirmed by the unchanged plasma corticosterone and aldosterone levels in immature rats and also in adult rats when the repeated treatment with MEN 11066 (15 days) was followed by the administration of a synthetic ACTH analogue. No change in 11β-hydroxylase or 21-hydroxylase activities was produced in vitro by the addition of 10 μM MEN 11066. Fifteen-day treatment with MEN 11066 did not produce changes in several rat hepatic enzymatic activities involved in the metabolism of xenobiotics. These results demonstrated that MEN 11066 is a potent inhibitor of aromatase which does not interfere with the cytochrome P450 involved in the synthesis of other steroids or in the metabolism of xenobiotics.

Suppression of uterine decidualization correlated with reduction in serum progesterone levels as a cause of preimplantation embryonic loss induced by diphenyltin in rats

In our previous study, diphenyltin dichloride (DPTCl) at 16.5 mg/kg and higher on days 0–3 of pregnancy was found to induce preimplantation embryonic loss in rats. In the present study, the effects of DPTCl on uterine decidualization in pseudopregnant rats, effects of ovarian hormones on uterine decidualization in ovariectomized rats, and effects of progesterone on the DPTCl-induced preimplantation embryonic loss in pregnant rats were determined. Female rats were given DPTCl by gastric intubation at 4.1, 8.3, 16.5, or 24.8 mg/kg on days 0–3 of pseudopregnancy and the decidual cell response was induced on day 4 of pseudopregnancy. The uterine weight on day 9 of pseudopregnancy served as an index of uterine decidualization. A significant decrease in uterine weight, which indicates suppression of uterine decidualization, was detected at 16.5 and 24.8 mg/kg. Ovarian weight and number of corpora lutea in the DPTCl-treated groups were comparable to the controls. A significant decrease in the serum progesterone levels was found at 16.5 and 24.8 mg/kg in pseudopregnant rats. The hormonal regimen consisting of progesterone and estrone-supported decidual development in ovariectomized rats given DPTCl. Pregnancy rate and number of implantations were significantly lower in the intact mated groups given DPTCl at 16.5 and 24.8 mg/kg on days 0–3 of pregnancy than in the control group and significantly higher in the groups given DPTCl plus progesterone than in the groups given DPTCl alone. These results show that reduction in serum progesterone levels is correlated with suppression of uterine decidualization and progesterone protects against preimplantation embryonic loss induced by DPTCl.

Rutin inhibits ovariectomy-induced osteopenia in rats.

Several studies suggest that polyphenols might exert a protective effect against osteopenia. The present experiment was conducted to observe the effects of rutin (quercetin-3-O-glucose rhamnose) on bone metabolism in ovariectomized (OVX) rats. Thirty 3-month-old Wistar rats were used. Twenty were OVX while the 10 controls were sham-operated (SH). Among the 20 OVX, for 90 days after surgery 10 were fed the same synthetic diet as the SH or OVX ones, but 0. 25% rutin (OVX + R) was added. At necropsy, the decrease in uterine weight was not different in OVX and OVX + R rats. Ovariectomy also induced a significant decrease in both total and distal metaphyseal femoral mineral density, which was prevented by rutin consumption. Moreover, femoral failure load, which was not different in OVX and SH rats, was even higher in OVX + R rats than in OVX or SH rats. In the same way, on day 90, both urinary deoxypyridinoline (DPD) excretion (a marker for bone resorption) and calciuria were higher in OVX rats than in OVX + R or SH rats. Simultaneously, plasma osteocalcin (OC) concentration (a marker for osteoblastic activity) was higher in OVX + R rats than in SH rats. High-performance liquid chromatography (HPLC) profiles of plasma samples from OVX + R rats revealed that mean plasma concentration of active metabolites (quercetin and isorhamnetin) from rutin was 9.46+/-1 microM, whereas it was undetectable in SH and OVX rats. These results indicate that rutin (and/or its metabolites), which appeared devoid of any uterotrophic activity, inhibits ovariectomy-induced trabecular bone loss in rats, both by slowing down resorption and increasing osteoblastic activity.

Disaccharide-trehalose inhibits bone resorption in ovariectomized mice

A method for the large-scale production of trehalose has been recently developed which has enabled us to investigate the biological functions of trehalose. In this study, we have investigated the effect of trehalose on bone resorption in ovariectomized mice as a model of osteoporosis. In ovariectomized ddY mice which were administered 100 mg/kg of trehalose orally during the 4 weeks after ovariectomy, the decrease in bone weight and in the contents of calcium and phosphorus of the femur attributed to estrogen deficiency were significantly suppressed when compared with that of ovariectomized mice administered vehicle only. Morphological observations of the tibia of ovariectomized mice revealed a marked decrease in trabecular bone compared with that of sham-operated mice. However, trabecular bone of ovariectomized mice receiving trehalose was clearly preserved. In experiments to examine the effects of trehalose on osteoclast formation from bone marrow cells, treatment resulted in a suppression of osteoclast differentiation, while a significant increase in osteoclast number was detected in ovariectomized mice receiving vehicle only. Furthermore, since administration of trehalose had no effect on the decrease in uterine weight which is due to estrogen deficiency, it seems unlikely that trehalose has an estrogen-like function. These results indicate that administration of trehalose to ovariectomized mice inhibits the increase of the osteoclast differentiation from the bone marrow leading to the prevention of the femoral bone loss attributed to estrogen deficiency, and further imply that ingestion of trehalose could be effective on the prevention of osteoporosis.

Effect of chronic administration of an aromatase inhibitor to adult male rats on pituitary and testicular function and fertility.

The aim of the present study was to evaluate the effects of the administration of a potent non-steroidal aromatase inhibitor, anastrozole, on male reproductive function in adult rats. As anastrozole was to be administered via the drinking water, a preliminary study was undertaken in female rats and showed that this route of administration was effective in causing a major decrease in uterine weight (P<0.02). In an initial study in male adult rats, anastrozole (100 mg/l or 400 mg/l) was administered via the drinking water for a period of 9 weeks. Treatment with either dose resulted in a significant increase ( approximately 10%) in testis weight and increase in plasma FSH concentrations (P<0.01) throughout the 9 weeks. Mating was altered in both groups of anastrozole-treated rats, as they failed to produce copulatory plugs. Histological evaluation of the testes from anastrozole-treated rats revealed that spermatogenesis was grossly normal. In a more detailed study, adult rats were treated with 200 mg/l anastrozole via the drinking water for periods ranging from 2 weeks to 1 year. Plasma FSH and testosterone concentrations were increased significantly (P<0.001) during the first 19 weeks of treatment. However, LH concentrations were increased only at 19 weeks (P<0.001) in anastrozole-treated rats, and this coincided with a further increase in circulating and intratesticular testosterone concentrations (P<0.05). No consistent change in inhibin-B concentrations was observed during the study. Suppression of plasma oestradiol concentrations could not be demonstrated in anastrozole-treated animals, but oestradiol concentrations in testicular interstitial fluid were reduced by 18% (P<0.01). Mating was again inhibited by anastrozole treatment, but could be restored by s.c. injection of oestrogen, enabling demonstration that rats treated for 10 weeks or 9 months were still fertile. Testis weight was increased by 19% and 6% after treatment for 19 weeks and 1 year, respectively. Body weight was significantly decreased (P<0.01) by 19 weeks of anastrozole treatment; after 1 year the animals appeared to have less fat as indicated by a 27% decrease in the weight of the gonadal fat pad. The majority of anastrozole-treated animals had testes with normal spermatogenesis but, occasionally, seminiferous tubules showed abnormal loss of germ cells or contained only Sertoli cells. Ten percent of anastrozole-treated animals had testes that appeared to contain only Sertoli cells, and one rat had 'giant' testes in which the tubule lumens were severely dilated. Morphometric analysis of the normal testes at 19 weeks showed no difference in the number of Sertoli cells or germ cells, or the percentage volumes of the seminiferous epithelium, tubule lumens and interstitium between control and anastrozole-treated rats. On the basis of the present findings, oestrogen appears to be involved in the regulation of FSH secretion and testosterone production, and is also essential for normal mating behaviour in male rats. Furthermore, these data suggest that the brain and the hypothalamo-pituitary axis are considerably more susceptible than is the testis to the effects of an aromatase inhibitor. Anastrozole treatment has resulted in a model of brain oestrogen insufficiency.

Effects of Ovariectomy on Cerebral Blood Flow of Rats

Recent reports suggest that estrogens may enhance cognitive function in postmenopausal women and women suffering from dementia of the Alzheimer’s type. One of several proposed mechanisms of action of estrogen has been an improvement in cerebral blood flow (CBF). The current study examined the effects of estrogen deprivation resulting from ovariectomy on the CBF of rats using the quantitative autoradiographic ¹⁴C-iodoantipyrine technique. CBF was assessed in passively restrained, awake adult rats at 6 weeks following ovariectomy (n = 10) or sham surgery (n = 10). Rats demonstrated marked endometrial atrophy and a decrease in uterine weight (mean 78%) in response to ovariectomy. Ovariectomized animals did not differ from control animals both in the magnitude and the topography of cortical or subcortical CBF, including the medial preoptic area, amygdala, arcuate nucleus and anterior hypothalamus, areas previously associated with high estrogen binding. These results suggest that in young, surgically ovariectomized animals, hormonal factors do not significantly contribute to changes in basal CBF.

Inhibition of ovarian compensatory hypertrophy by the administration of methyl parathion in hemicastrated albino rats

Methyl parathion, an organophosphorus pesticide that is a potent acetylcholinesterase inhibitor in animals, was administered IP in graded doses from 2.5 to 5.0 mg/kg body weight to normal hemicastrated virgin rats for 15 consecutive days. Sham-operated and hemicastrated control groups were treated with a similar quantity of olive oil vehicle. The vaginal smears and body weights of treated and control groups were recorded daily and rats were sacrified on the 16th day. The ovaries, adrenals, liver, kidney, and uterus were removed and weighed, and the ovary from each animal was serially sectioned and stained for histologic studies. The hemicastrated control group revealed a significant increase in ovarian weight with 45% hypertrophy and a significant increase of total healthy and atretic follicles when compared with sham-operated control rats. Treatment with 2.5 and 3.5 mg methyl parathion revealed no change in the ovarian weight with 48 and 42% hypertrophy, respectively, and no change in healthy and atretic follicles when compared with hemicastrated oil-treated controls. However, treatment with 4.0 and 5.0 mg methyl parathion resulted in a significant decrease in ovarian weight gain with 13 and 8% hypertrophy, respectively, a significant decrease in the number of healthy follicles, and no change in the atretic follicles. The number of estrous cycles and duration of each estrous cycle were affected significantly with 3.5, 4.0, and 5.0 mg methyl parathion treatment when compared with controls. There were no significant changes in adrenal, liver, kidney, or uterine weight in the methyl parathion-treated groups except a decrease in uterine weight with 5.0 mg treatment when compared with oil-treated hemicastrated controls.

Effects of the Progesterone Antagonists Onapristone (ZK 98 299) and ZK 136 799 on Surgically Induced Endometriosis in Intact Rats

The effects of the progesterone antagonists (antiprogestins) onapristone (ZK 98 299) and ZK 136 799 on surgically induced endometriosis were studied in intact female rats. Endometriosis was induced by transplanting homologous endometrium to the parietal peritoneum of the abdominal wall (location A) and to the mesentery of the small intestine (location B). The animals were treated daily for 4 weeks at doses of 0.4 and 2.0 mg onapristone or ZK 136 799. The growth of the endometriosis-like foci was measured with a calliper during both pre- and post-treatment laparotomy. Both antiprogestins exerted inhibitory effects on the growth of the endometriosis-like foci in terms of complete remission. A 40 and 50% remission of endometriosis was observed at each location after the administration of 2.0 mg onapristone, whereas 50 and 63% (location A) and 50 and 75% (location B) remissions were found after the administration of 0.4 and 2.0 mg of ZK 136 799 respectively. ZK 136 799 was also more potent than onapristone in growth inhibition (85 versus 48% for location B) in animals with persistent endometriosis. Growth inhibition of the endometriosis-like foci was confirmed by histology and immunohistochemical staining of the proliferating cell nuclear antigen. The antiprogestins caused a reduction in glandular and luminal epithelial cells in the ectopic endometrium. Both antiprogestins tended to cause a decrease in uterine weight. Unlike the inhibitory effects in the ectopic endometrium, both onapristone and ZK 136 799 exhibited some stimulatory effects on the epithelial cells within the eutopic endometrium. Serum 17 beta-oestradiol concentrations did not vary significantly among the different treatment groups. No antiglucocorticoid effect of the antiprogestins was observed at either dose. This study indicates that the antiprogestins onapristone and ZK 136 799 exhibit antiproliferative effects in the ectopic but not the eutopic endometrium via mechanisms which remain to be established. The better efficacy of ZK 136 799 is more likely caused by its higher antiprogestagenic activity than its partial androgenic activity. These findings may be a further indication of the future potential of antiprogestins such as onapristone and ZK 136 799 in the treatment of endometriosis.

Estrogenic and antiestrogenic properties of clomiphene citrate in laboratory mice

The estrogen agonistic and antagonistic properties of clomiphene citrate were investigated in the mice. Clomiphene citrate was tested at various doses of 0.1, 1.0, 10 and 100 μg for three consecutive days in immature and mature bilaterally ovariectomized mice. Clomiphene citrate showed uterotrophic activity in both immature and ovariectomized conditions. The lower doses of 0.1 and 1.0 μg were ineffective to show any uterotrophic stimulation. Clomiphene citrate at 10 μg dose produced 305.56% increase in uterine weight i.e., 27.70 ± 0.24 vs 6.83 ± 0.06 in immature and 182.27% i.e., 42.68 ± 1.12 vs 15.12 ± 0.57 in ovariectomized mice. Clomiphene citrate at 100 μg dose showed significant uterotrophic effect e.g., 435.57% i.e., 36.58 ±0.34 vs 6.83 ± 0.06 in immature and 586% i.e., 103.80 ± 0.60 in ovariectomized mice. When clomiphene citrate was administered in combination with 0.32 μg of estradiol 17-β it caused significant antagonistic effect (decrease in uterine weight) at 10 and 100 μg respectively. Clomiphene citrate at 10 μg dose produced 32% i.e., 28.93 ± 0.43 vs 38.04 ± 2.68 in immature and 35% i.e., 59.64±1.44 vs 83.34 ±0.25 in ovariectomized mice respectively. Histological observation clearly showed that clomiphene citrate at 10 and 100 μg doses did not cause any differential hypertrophy of the epithelial layer. Similar doses in combination with estradiol produced significant antagonistic effect on uterine weight and luminal epithelial cell height.