Stereological study of the effects of letrozole and estradiol valerate treatment on the ovary of rats

Noorafshan, Ali; Ahmadi, Maryam; Mesbah, Fakhroddin; Karbalay‐Doust, Saied

doi:10.5653/cerm.2013.40.3.115

Cited by 31 publications

(40 citation statements)

References 17 publications

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“…Despite the lack of significant differences between the two groups regarding preantral and antral follicles, similar to other studies (14,20,21), the preovulatory follicle and corpora lutea were significantly lower in EV-treated mice. This can be related to the reduced ovulatory rate or anovulation, explaining the poor fertility rate in this group.…”

Section: Body Weight and Fertility Ratesupporting

confidence: 68%

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Polycystic Ovary Morphology (PCOM) in Estradiol Valerate Treated Mouse Model

Amini¹,

Tehranian²,

Movahedin³

et al. 2016

IJWHR

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IntroductionPolycystic ovary syndrome (PCOS) is one of the most common endocrinopathies found among 5%-10% of reproductive age women. It is a common cause of infertility due to anovulatory (1) and hyperandrogenism (2). The name of PCOS is based on ovarian morphological changes in women who suffer from menstrual disturbances and hyperandrogenism symptoms, so polycystic ovary morphology (PCOM) can be a notable feature of PCOS (3). PCOM is revealed by some ovarian morphological abnormalities such as polycystic and enlarged ovaries (4). Although many extra ovarian causes are raised in the pathophysiology of PCOS, ovarian dysfunction plays the most important role in this field (5). Although all women with PCOS are in risk of hormonal and glucose metabolism disturbances, insulin resistance, dyslipidemia, metabolic syndrome, cardiovascular disease, and endometrial hyperplasia (4), it seems that PCOS women with PCOM are in risk of elevated serum DHEA-S levels and also taking a higher daily dose of insulin in comparison to PCOS women without PCOM (6).There are many hypotheses for the etiology of PCOS (7), but the exact initiating event in the pathophysiology of the syndrome is not entirely clear and remains poorly understood. Since the study of pathophysiology or any manipulation for treatment of PCOS/PCOM in human faces some serious logistic and ethical limitations; animal modeling is a good choice to improve the understanding of the abstruse aspects of PCOS (8). Since the 1960s, many animal models such as rodents, sheep and nonhuman primates have been applied for this purpose. Using the mouse models can provide an all-purpose tool for studying and understanding the comprehensive biologic mechanisms of PCOS/PCOM. They have stable genetic backgrounds, shorter reproductive and estrous cycle and generation times, and reasonably priced. Besides, these models have shown same reproductive and metabolic conditions as human PCOS (9). Different procedures have been suggested to produce PCOS model including prenatal or pre-pubertal androgen exposure (10,11), aromatase inhibitor or estradiol administration (11-13), and transgenic models (11). AbstractObjectives: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age. Polycystic ovary (PCO) is a criterion for PCOS. Several animal models of polycystic ovary morphology (PCOM) are developed in order to study PCOS aspects. The present study aimed to develop a polycystic ovarian model in mice. Materials and Methods: Thirty-four young adult female mice were divided equally into estradiol valerate (EV) treated and control groups. Mice in experimental group (n = 18) received a single dose injection of EV (IM, 4 mg/kg). Weight and fertility rate of all mice were recorded. Morphology of ovarian follicles was assessed too. Chi-square and independent t test were used for comparison between groups. P value less than 0.05 was considered as significant level. Results: After 60 days, the weight of EV-treated mice was significantly lower than control (P ...

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Section: Body Weight and Fertility Ratesupporting

confidence: 68%

“…Mice in experimental group (n = 14) received an IM injection of EV (4 mg/kg dissolved in 0.4 ml of sesame oil) (Aburaihan Co., Iran), to induce PCOM (14). Mice body weight was measured on the first day and 60th day of the study before removal of the ovaries.…”

Section: Methodsmentioning

confidence: 99%

Polycystic Ovary Morphology (PCOM) in Estradiol Valerate Treated Mouse Model

Amini¹,

Tehranian²,

Movahedin³

et al. 2016

IJWHR

View full text Add to dashboard Cite

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“…Where ln refers to the distances from the sampling point to the edge of the particle (such as the nucleus or the cell) (Calado et al, 2003;Myers et al, 2004;Noorafshan et al, 2013).…”

Section: Article In Pressmentioning

confidence: 99%

“…Using Cavalieri method, the total volume of the ovary was estimated: is the total number of superimposed points on the cortex. In turn, the volume density (Vv) was multiplied by the total volume of ovary to estimate the volume of cortex and medulla (Howard and Reed, 1998;Karbalay-Doust and Noorafshan, 2012;Noorafshan et al, 2013;Soleimani Mehranjani et al, 2010).…”

Section: Estimation Of the Volume Of Ovary Cortex And Medullamentioning

confidence: 99%

N-acetylcysteine improves function and follicular survival in mice ovarian grafts through inhibition of oxidative stress

Mahmoodi

Mehranjani

Shariatzadeh

et al. 2015

Reproductive BioMedicine Online

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The effect of N-acetylcysteine (NAC) on mouse ovary heterotopic autotransplantation was investigated. Mice (age 4-5 weeks) were divided into the following groups: control; autograft plus NAC (150 mg/kg daily intraperitoneal injection) and autograft plus saline (n = 6 per group). Groups were treated from 1 day before until 7 days after transplantation. After 28 days, ovary compartments were estimated stereologically. Plasma malondialdehyde, progesterone, oestradiol concentrations and the percentage of apoptotic follicles were measured to evaluate the rate of oxidative stress and ovarian graft function. The mean total volume of ovary, cortex and the number of follicles was significantly higher (all P < 0.001) in the autografts plus NAC group compared with the saline group. In the autografts plus NAC group, the mean percentage of apoptotic follicles (P < 0.001) and malondialdehyde concentration (P < 0.001 day 7; P < 0.05 day 28) were significantly lower, whereas oestradiol concentration was significantly higher (P < 0.05) compared with the saline group. Although NAC cannot compensate the above parameters to the control level, it considerably improves follicular survival and development and also the structure and function of transplanted ovaries, through reducing oxidative stress and apoptosis.

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“…However, after a single injection of the EV, it will take about 8–12 weeks to induce PCOS, therefor the stress of injection is reduced, it is well known that stress causes irregularities in the menstrual cycle. The EV-induced PCOS model displays characteristic morphological alterations in the ovary [ 26 ], particularly the multi-cystic follicle; as previously shown [ 27 , 28 ], and mention shortly in results section, which is typically observed in human PCOS. In addition, the EV-induced PCOS model is used in many laboratories, develops hypertension and increases sympathetic activity [ 29 ]; these effects lead to increased blood glucose as in this study and it is utilized for autoimmune disorder responses in PCOS [ 30 ].…”

Section: Discussionmentioning

confidence: 84%

Does metformin improve in vitro maturation and ultrastructure of oocytes retrieved from estradiol valerate polycystic ovary syndrome-induced rats

et al. 2015

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BackgroundMetformin decreases polycystic ovary syndrome (PCOS) symptoms, induces ovulation, and may improve developmental competence of in vitro oocyte maturation. This study was designed to define the effects of metformin on the characteristics of in vitro oocyte maturation in estradiol valerate (EV) PCOS-induced rats.MethodsForty-five adult female Sprague–Dawley rats were randomly divided into control; sham and PCOS-induced (treated by a single dose of estradiol valerate, 4 mg/rat, IM) groups. The body weight was measured weekly for 12 weeks. At the end of week 12, the serum levels of testosterone, estrogen, progesterone, LH, and FSH and blood glucose of all the rats were measured. About 380 cumulus oocyte complexes (control, 125; sham, 122; PCOS-induced rats, 133) were incubated in Ham’s F10 in the absence and/or presence of metformin (M 5−10) for 12, 24, 36, and 48 h. The cumulus cells expansion and nuclear and cytoplasmic maturation of the oocytes was evaluated using 1 % aceto-orcein staining, and transmission electron microscopy (TEM).ResultsNo significant differences were observed in the body weight of the rats. The serum level of testosterone was reduced, and progesterone and LH were significantly increased in the PCOS-induced rats (p < 0.05). However, no significant differences were observed in the serum levels of estrogen and FSH among the groups. Blood glucose level was higher in the PCOS-induced rats than control, (p < 0.01). The expansion of cumulus cells was observed in the metformin-treated oocytes. The oocytes retrieved from PCOS-induced rats show a stage of meiotic division (GVBD, MI, A-T, and MII) in 57.12 % of metformin-untreated and fairly significantly increased to 64.28 % in metformin-treated oocytes, (p < 0.05), but no differences were observed in the MII stage within groups. The redistribution of some cytoplasmic organelles throughout the ooplasm, particularly the peripheral cortical granules, was defined in the metformin-treated oocytes.ConclusionsSingle dose of EV can creates a reversible PCO adult rat model. Metformin enhances the COCs to initiate meiotic resumption at the first 6 h of IVM. In our study the metformin inability to show all aspects of in vitro oocyte maturation and may be resulted from deficiency of EV to induce PCOS.

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Stereological study of the effects of letrozole and estradiol valerate treatment on the ovary of rats

Cited by 31 publications

References 17 publications

Polycystic Ovary Morphology (PCOM) in Estradiol Valerate Treated Mouse Model

Polycystic Ovary Morphology (PCOM) in Estradiol Valerate Treated Mouse Model

N-acetylcysteine improves function and follicular survival in mice ovarian grafts through inhibition of oxidative stress

Does metformin improve in vitro maturation and ultrastructure of oocytes retrieved from estradiol valerate polycystic ovary syndrome-induced rats

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