Atretic Ovarian Follicles Research Articles

The Effect of Tamoxifen Citrate on Granulosa Cells of Ovarian Follicles in Adult Female Rats: Light Microscopic Study.

Tamoxifen is a drug that has been used extensively as a chemotherapeutic agent for breast cancer. It should be taken for a long period, from few weeks up to many years, so it can induce gynecological and nongynecological complications. Present study was conducted to clarify the histopathological effects of tamoxifen intake on the ovarian follicles of rats and evaluate the promising recovery after drug withdrawal. Adult female albino rats (n = 24) were randomly divided into four groups. Group I: Control rats without treatment. Group II: Rats received olive oil vehicle. Group III: Rats received 5 mg/kg daily of tamoxifen dissolved in olive oil by oral administration for 4 weeks. Group IV: Rats received tamoxifen as in Group III then will be kept for another 4 weeks without treatment for recovery. Then, the rats were anaesthetized and the ovaries were removed and prepared for histological assessment by light microscope. The ovarian histological findings in the ovary of Group III revealed an increase in atretic ovarian follicles, appearance of cystic ovarian follicles, and cystic corpus luteum. The granulosa cells of ovarian follicles were disorganized with vacuolation of their cytoplasm, increased number of pyknotic nuclei, fragmented nuclei, and apoptotic bodies. After the withdrawal of drug, the ovarian tissue showed slight improvement with the appearance of some atretic follicles with degenerated oocyte and stromal hyperplasia. Based on the results, tamoxifen induced marked histological changes in the ovary. If tamoxifen is mandatory for the prevention of breast cancer, frequent gynecological examination should be carried out to detect any side effects.

High Housing Density-Induced Chronic Stress Diminishes Ovarian Reserve via Granulosa Cell Apoptosis by Angiotensin II Overexpression in Mice.

Repeated and prolonged stress causes hypothalamic-pituitary-adrenal (HPA) dysregulation. Excessive hypothalamic-pituitary-adrenal axis activity has been linked to inadequate activation of the hypothalamus-pituitary-ovarian axis, which controls the growth and development of ovarian follicles and oocytes. Therefore, we assessed the ovarian reserve under high-housing-density-induced prolonged stress, and investigated the mechanisms underlying diminished ovarian reserve in this study. Eight-week-old female C57BL/6 mice were housed for 10 weeks under different housing densities. We then assessed hormone levels, performed histology and immunohistochemistry analyses of ovarian follicles, evaluated ovarian mRNA expression, and measured angiotensin II-mediated apoptosis in vitro. More densely housed mice presented increased corticosterone levels and decreased follicle-stimulating and luteinizing hormone levels. Moreover, mice exposed to prolonged ordinary stress showed a reduced level of serum anti-Müllerian hormone and an increased number of atretic ovarian follicles. Stressed mice showed increased levels of angiotensinogen and angiotensin II in the ovaries and serum. Furthermore, our in vitro study confirmed that high-housing-density-related stress induced granulosa cell apoptosis, resulting in diminished ovarian reserves. Collectively, our findings highlight the importance of women managing everyday stress to maintain their reproductive health.

An autofluorescence-based survey of late follicular atresia in ovaries of a teleost fish (Thunnus thynnus).

In this study, the authors examined late atretic follicles in the ovaries of Atlantic bluefin tuna, Thunnus thynnus (Linnaeus 1758), at different times of the year using transmitted light and epifluorescence microscopy. Atresia (degeneration and resorption of developing ovarian follicles) is a natural process involved in fecundity downregulation in teleosts and is substantially enhanced in stressful conditions. Early (α and β) atretic stages of yolked oocytes have a relatively short duration in seasonally reproducing species, whereas later (γ and δ) atretic follicles (LAF) persist for longer time in the ovary, serving as a sign of previous vitellogenic activity. LAF can thus be used as reliable markers of maturity during non-reproductive periods. Lipofuscin granules accumulate in the cytoplasm of LAF cells as a result of lysosomal digestion of oocyte components. Taking advantage of the well-known autofluorescent properties of lipofuscins, LAF may be identified in unstained histological sections under fluorescence microscopy using appropriate excitation and emission wavelengths. The authors explore in this study the applicability of fluorescence microscopy to provide a fast and effective method to assess late atresia in fishes. This method may be particularly useful to determine sexual maturity in individuals sampled long after the spawning season, where LAF are difficult to detect in standard histological sections. Furthermore, LAF autofluorescence provides a rapid way to quantify late atresia in fishes using image analysis.

Expression of PGC-1ɑ in Ovarian Tissue of PCOS Rat Model

To investigate the expression of peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) in the ovarian tissue of polycystic ovary syndrome (PCOS) rat model and obese PCOS rat model, and the possible mechanism of PCOS. Thirty SD rats were randomly divided into control group, PCOS rat model group and obese PCOS rat model group. DHEA dissolved in 0.2 mL soybean oil was injected daily into the rats of two PCOS groups for 21 d. Rats in obese PCOS model group were added with high-fat diet based on DHEA modeling, and each group had 10 rats. Body mass were measured before and on the 22 nd day after modeling. The serum testosterone (T) levels were measured by abdominal aortic blood, and the ovarian tissues of rats were taken for histological changes were observed by HE staining, immunohistochemical staining and Western blot to detect PGC-1ɑ protein expression. The body mass of rats in each group increased after modeling, and the body mass of rats in PCOS group and obese PCOS group increased significantly ( P<0.05). The serum T concentration of two PCOS model groups was higher than that of control group ( P<0.01). The serum T concentration in obese PCOS model group was higher than that in the PCOS group ( P<0.05). The results of HE staining of rat ovarian tissue showed that there were follicles and a small amount of corpus luteum at different developmental stages in the control group, and the granulosa cells were arranged in 4-6 layers. The number of immature small follicles in the two PCOS groups was significantly increased. The granulosa cells were arranged in 1-3 layers, relatively looser, and some follicles were atresia. In the obese PCOS group, the diameter of ovarian atretic follicles increased, the number of granulocyte layers decreased, and oocytes disappeared more obviously. Immunohistochemical staining showed that the PGC-1ɑ protein was mainly expressed in the cumulus and granulosa cells of ovarian tissue in the control group. The mean gray level of PGC-1ɑ protein expression in PCOS group (0.53±0.06) and obese PCOS group (0.36±0.03) was lower than that of the control group (0.75±0.03), with the statistical difference ( P<0.05). PGC-1ɑ expression in the obese PCOS group was lower than that in the PCOS group ( P<0.01). The results of Western blot were consistent with those of immunohistochemical staining. PGC-1ɑ is associated with damage of ovarian granulosa cells in high-fat environment. The decrease of PGC-1ɑ expression in granulosa cells of ovarian follicles may be an important cause of PCOS development.

Pregabalin induced reproductive toxicity and body weight changes by affecting caspase3 and leptin expression: Protective role of wheat germ oil

Pregabalin (PGB) drug abuse is common among the youth. It substituted tramadol before its recent schedule as a controlled drug since April 2019. PGB is an antiepileptic drug acting on the central nervous system. It blocks calcium channels regulating the action of neurotransmitters and causing prolonged depolarization. The present study aimed to investigate the toxic effect of long term pregabalin abuse on the reproductive function and body weight in both male and female albino rats and to evaluate the ameliorative effect of wheat germ oil (WGO). Forty-eight rats were randomly divided into eight groups. The first four groups were males and they were treated as follows: control group (1.5 mL saline), WGO group (1.5 mL L/kg), PGB group (300 mg/kg), and protective group (PGB + WGO). All doses were administrated once per day for 60 days by gastric gavage. The second four groups were females. They were divided and treated the same as the male groups. Pregabalin caused significant weight loss, decreased serum triglyceride level, and increased leptin gene expression in all rats. PGB affected male rats reproduction by decreasing total testosterone serum level and inhibiting spermatogenesis. Reproductive toxicity in females was caused by decreasing pituitary steroids, increasing gonadal hormones, and increasing the number of atretic ovarian follicles. Mechanism of toxicity may be attributed to the PGB oxidative stress effect that induced apoptosis and caused diffuse gonadal atrophy. WGO showed a protective effect on PGB induced toxicity as all measured parameters were relatively improved.

Effects of pituitary extract, ovaprim, and bitter leaf (Vernonia amygdalina) on the histopathology of African catfish (Clarias gariepinus)

The development of aquaculture in Nigeria is constrained by the inadequate supply of high quality of fingerlings of African catfish (Clarias gariepinus). There are conflicting reports on the reproductive efficacy of Vernonia amygdalina when compared with the synthetic hormone Ovaprim (OV) and Pituitary Extract (PE) on C. gariepinus. The histopathology of select organs in catfish treated with generic Ovaprim (OV), Pituitary Extract (CPE), and aqueous extract of Vernonia amygdalina (VAE) were evaluated. Sixteen female C. gariepinus (average weight of 1 kg) wereevenly and randomly distributed to four groups. Fish in groups A, B, C, and D were injected intramuscularly with aqueous solutions of OV (0.5 mL/kg), PE (5 mg/kg), VAE (10 mg/kg), and distilled water (DW; 0.5 ml), respectively. Histological examinations of the ovary, liver, kidney, and spleen were carried out. Histopathology revealed that OV- and PE-treated groups showed synchronous and synchronous ovarian development, vacuolar change of hepatocytes, thinning of hepatic cords, reduced renal haemopoietic compartments, tubular degeneration and necrosis, and decrease in splenic periarteriolar lymphoid sheaths (PALS). VAE-treated groups had asynchronous ovarian development with atretic ovarian follicles, widespread vacuolar change of hepatocytes, intact renal tubular and hemopoietic compartments, and preponderance of large and coalescing splenic PALS. We conclude that VAE is an ineffective spawning agent, especially when compared with OV and PE, as VAE could not induce synchronous gonadal development. However, VAE may have immunopotentiating, nephroprotective, and haemopoietic properties.

Pengaruh Monoklonal Antibodi Bovine Zona Pelusida 3 (bZP3) terhadap Diameter dan Atresia Folikel Ovarium Mencit (Mus musculus)

Objectives: To identify the effect of monoclonal antibody bZP3 at ovarian follicles that undergo atresia and diameter of various ovarian follicles.Materials and Methods: This is a true experimental research with post only control group design. Samples were 36 female mices (Mus musculus) which is divided into 6 groups, there are 3 control groups (group 1, 2, and 3) injected by Phospatase Buffer Saline (PBS) 50µl and 3 treatment groups (group 4, 5, and 6) injected by Mab bZP3 50µl. Group 1 and 4 terminated at 5th day, group 2 and 5 terminated at 10th day, and group 3 and 6 terminated at 20th day. Evaluation of atretic ovarian follicles and diameter of ovarian follicles performed by hematoxylin eosin (HE) and the data processed by parametric statistic.Results: There are no significant in different among groups in the aspect of atretic follicles and diameter of folicles (p&gt;0.05), but descriptively, number of follicles undergo atresia of the follicle primary, secondary, and tertiary treatment group was higher than the control group, except on the 20th day of observation time.Conclusion: administration of Mab bZP3 had no effect to amount of atretic follicles and diameter of folicles during observation time.

Effects of bisphenol A on ovarian follicular development and female germline stem cells.

Bisphenol A (BPA), one of the most frequently detected emerging pollutants in the environment, has been implicated in adverse effects in male and female reproduction at extremely low concentrations. This study aimed to investigate the effects and potential mechanism of BPA on mouse ovarian follicular development and female germline stem cells (FGSCs). Female CD-1 adult mice were administered gradient concentrations of BPA (12.5, 25, and 50mg/kg/day) by intraperitoneal injection. We found that the number of atretic ovarian follicles was significantly increased at high BPA concentrations. Additionally, the numbers of primordial follicles, primary follicles, and corpus luteum (CL) were significantly reduced at high BPA concentrations. Interestingly, the number of FGSCs was remarkably reduced in BPA-treated ovaries. Furthermore, the increased apoptotic rate of FGSCs in vitro was triggered by BPA accompanied by increased BPA concentrations. To investigate the mechanism of BPA in ovarian follicular development, 193 differentially expressed proteins were identified in BPA-treated ovaries by the isobaric tags for relative and absolute quantification-coupled 2D liquid chromatography-mass spectrometry technique. A total of 106 proteins were downregulated and 85 proteins were upregulated. Among these proteins, the apoptosis-related protein SAFB-like transcriptional modulator (SLTM) was remarkably upregulated, and this result was consistent with western blotting. Taken together, our results suggest that an ovarian follicular development, especially, the development of primordial follicles, primary follicles, and the CL, is inhibited by high BPA concentrations, and the ovarian follicle atresia is initiated by BPA through upregulated expression of SLTM. Furthermore, BPA induces apoptosis of cultured FGSCs. The effect of BPA on ovarian follicular development and FGSCs, especially the effect on FGSCs, suggests a novel mechanism of how BPA causes female infertility.

Atretic Ovarian Follicles Morphology and Immunolocalization of Active Caspase-3 in Algerian Bedouin Goat (Capra hircus) Ovaries

Atretic Ovarian Follicles Morphology and Immunolocalization of Active Caspase-3 in Algerian Bedouin Goat (Capra hircus) Ovaries

Reproductive biology of the cockfish, Callorhinchus callorynchus (Chondrichthyes: Callorhinchidae), in coastal waters of the northern Argentinean Sea

ABSTRACT The cockfish, Callorhinchus callorynchus, is a widely distributed holocephalan in the south-western Atlantic and an important resource for Argentinean fisheries. The reproductive characteristics of this species were studied in northern Argentinean coastal waters, where specimens arrive seasonally (winter-spring). Sexual dimorphism in maximum precaudal length (PCL) and total body mass (TM) was found, being females (PCL=630 mm; TM=3330 g; n=167) larger and heavier than males (PCL=482 mm; TM=1630 g; n=19). Maturity size for females was 466.22 mm PCL, representing 74% PCL of the largest female sampled. The mean number of ovarian follicles was 8.37 (± 4.84). The highest values of ovarian follicles diameter, gonadosomatic and oviducalsomatic indices were found in spring. A high proportion of mature females (44%) had atretic ovarian follicles, suggesting that they were in the resting stage of their reproductive cycle. The low number of mature males recorded and the absence of mature females with spermatophore masses or egg cases indicate that the study area would not be a reproductive zone. The seasonal presence of C. callorynchus in this region could be related to trophic movements. These results, obtained in an area with high fishing pressure on chondrichthyans, will be useful for implementing conservation and management measures.

Lysophosphatidic acid expression in theca cells depends on the type of bovine ovarian follicle.

Lysophosphatidic acid (LPA) exerts various actions on the mammalian reproductive system. In cows, LPA stimulates the synthesis and secretion of luteotropic factors in the ovary, which affects the growth and development of ovarian follicles. The role of LPA in granulosa cells, oocyte and oocyte-cumulus complex (COC) has previously been investigated; but its role in the theca layer, which is an important structural and functional component of the ovarian follicle, is still unclear. The goal of this study was to investigate the expression of LPA in theca cells originating from different bovine ovarian follicle types. Theca cells were separated from healthy, transitional and atretic ovarian follicles, based on intrafollicular estradiol: progesterone ratios. LPA concentration in the follicular fluid (FF) in different follicle types was measured, and expression of the enzymes responsible for LPA synthesis (autotaxin [AX], phospholipase A2 [PLA2]) and receptors for LPA (LPAR1-4) were determined. The obtained results confirmed the follicle-type dependent presence of LPA in the FF of the bovine ovarian follicles. The highest concentration of LPA was detected in follicles classified as healthy and dominant. LPAR1-4, PLA2 and AX expression in theca cells in all of the types of follicles examined were detected at mRNA and protein level. These results suggest that theca cells can be a source of LPA synthesis other than granulosa cells and COCs, as well as the target for its action in the bovine ovarian follicle, with PLA2 and LPAR4 playing major roles in LPA synthesis and action.

GOSSYPOL PROMOTES THE DEGENERATION OF CHICKEN OVARIAN FOLLICLES IN VITRO

Gossypol, a phenolic compound produced by the pigment glands of cotton, is known to affect male reproduction. In females, exposure to gossypol has been associated with interference with the estrous cycle and embryo development. In laying hens fed cottonseed, gossypol was found to reduce egg production and weight and to cause discoloration of the egg yolk and/or albumen. It is probable that gossypol directly affects ovarian follicles, but this has not been confirmed experimentally yet. Thus, the aim of the present study was to determine if gossypol affected cultivated ovarian follicles of the chicken. Ovarian follicles of adult female chickens were cultivated with different concentrations of gossypol (0, 5, 10 and 20 μg/mL) and classified according to the stage of development as primordial, transitional, primary, secondary or antral, and as viable or atretic. The percentages of viable and atretic follicles in the ovaries cultivated for 24 hours in the presence of gossypol were significantly different from those of the controls for all types of follicles except for secondary follicles, but in all types after cultivation for 7 days. The percentage of viable follicles was higher than that of atretic follicles in ovaries cultivated without gossypol. In contrast, ovaries cultivated with gossypol showed a predominance of atretic follicles. Gossypol increased the proportion of atretic follicles at all stages of development in cultivated chicken ovaries. Thus, gossypol may affect ovarian follicular viability and maturation, which might interfere with female fertility.

Reproductive toxicity of chlorpyrifos tested in zebrafish (Danio rerio): Histological and hormonal end points.

This study was carried out to find out whether exposure to environmentally relevant concentration of chlorpyrifos (CP) modulates reproductive competence. To understand this, eight adult male and eight adult female zebrafish (Danio rerio) were exposed to 200 µg/L of CP for 24, 48, 72, and 96 h. Vitellogenin levels did not show much change in female fish, whereas in male the levels increased with increasing exposure time thereby indicating estrogenecity of the toxicant. Attenuation of serum 11-ketotestosterone in male and serum 17β-estradiol in female was noticed in the exposed fish and thus signified interference of CP in the reproductive endocrine system. Structural damage common to both the gonads was vacuolization. Elongation of seminiferous tubules in testes and atretic follicles in ovary was also observed.

Ultrastructural features of atretic ovarian follicles in buffalo (Bubalus bubalis)

The process of follicular development and features of morphological changes are essential to understand the factors involved during folliculogenesis and to improve fertility in buffalo. Hence the objective of the present study was to report ultrastructural features of atretic ovarian follicles in buffalo. In the early stage of atresia, the involvement of mitochondria was observed and whereas in the later stages of atresia, involvement of macrophages were observed. The granulosa cells of buffalo atretic tertiary follicles were observed to contain undulation of the nuclear membrane, crescent formation of the pyknotic nuclei and loopiness and undulations of the basal lamina. These features are similar to the reports in other species. The involvement of mitochondria in the early stage of atresia suggested the probable role of a reactive oxygen free radical induced damage.

Adverse effects of monosodium glutamate on the reproductive organs of adult Female albino rats and the possible ameliorated role of carob (Ceratonia Siliqua).

Monosodium glutamate (MSG) is a sodium salt of glutamic acid that enhances the flavor of certain foods. It plays an important role in the pathogenesis of anovulatory infertility. This study was carried out to evaluate the histological, histochemical as well as immunohistochemical effects of MSG on the ovaries, uterus and vagina of adult female Wistar rats and the possible ameliorative role of carob (Ceratonia Siliqua). In the present work, twenty- four Wistar rats were divided into four groups (n=6): Control group received 0.5ml saline solution, carob-group, feeding on diet containing 5% carob powder, MSG- treated group received 400 mg/kg b.wt and ameliorative group received MSG 400mg/kg b.wt simultaneously with feeding on diet containing 5% carob powder. In MSG treated rats, the serum estrogen level was significantly decreased. The histopathological results showed ovarian atretic follicles, fragmented oocyte, vascular congestion, and vacuolated stroma. The uterus exhibited a comparative reduction in the endometrial thickness and loss of endometrial glands associated with cellular hyperplasia and reduced vacuolated cells. In MSG treated group, the vaginal epithelium appeared relatively thin, folded and hypertrophied with sign of cornification. Histochemically, a weak reaction for PAS stain was remarked in investigated sections of MSG- treated rats. On the other side, an intense positive reaction for silver stain was recorded in the ovarian stroma and peripheral layers of atretic follicles as well as spreading in endometrium of uterus and lumina sheath of vagina. Immunohistochemically, MSG-treated group exhibited intense positive reaction for CD31and CD68 and activated caspase3 compared to carob-ameliorated MSG and the control. The authors concluded that, feeding of MSG-treated group on diet containing 5% carob powder led to marked amelioration of histopathological lesions induced in ovaries, uterus and vagina by MSG attributed to the biological benefits of its phytochemical components.

The effect of water quality on the immunoreactivity of stress-response cells and gonadotropin-secreting cells in the pituitary gland of Nile tilapia, Oreochromis niloticus.

The present experiments investigated the effect of water quality characteristics on the condition factor, the ovarian activity, cortisol level, and the immunoreactivity of stress-response cells (adrenocorticotropic hormone; ACTH- and melanin stimulating hormone; MSH- and somatolactin; SL- secreting cells) and gonadotropin (GTH)-secreting cells in the pituitary gland of Nile tilapia, Oreochromis niloticus. After 3 months of exposure to mixtures of water from different sources (Tap and Lake Manzalah waters), with high levels of minerals and heavy metals, water quality affected the number, size, and immunostaining of stress-response-immunoreactive (ir) cells and GTH-ir cells, which showed a dramatic decrease in their size. The integrated optical density (IOD) of immunoreactivity of MSH- and GTH- cells was significantly increased; however, it was significantly decreased for ACTH- and SL- cells. Also, high levels of cortisol were observed in females exposed to waters with high concentrations of minerals and heavy metals. In parallel, low values of gonadosomatic index (GSI%) and the ovarian histology revealed a decrease of maturing follicles concomitant with an increase of atretic follicles in females exposed to Lake Manzalah polluted water. Taken together, the increased activity of stress-response-ir pituitary cells, serum cortisol level and ovarian atretic follicles in response to elevated concentrations of minerals and heavy metals, supports the possible role of ACTH, MSH, and SL in the adaptive stress response of fish. Therefore, minerals and heavy metals must be considered when discussing tilapia aquaculture status.

Expression characteristics of MMP-2 and MMP-9 in guinea pig ovaries during the estrous cycle.

We investigated the expression characteristics of matrix metalloproteinases (MMP)-2 and MMP-9 in the ovaries of normal adult guinea pigs during the estrous cycle. The estrous cycle was classified according to the appearance of the vaginal orifice and by vaginal exfoliated cell smears. Guinea pigs that had experienced at least two normal estrous cycles were selected. Ovaries were collected from guinea pigs at proestrus or metestrus (N = 6). The expression characteristics of steroidogenic acute regulatory protein (StAR), MMP-2, and MMP-9 were investigated by hematoxylin and eosin staining and immunohistochemical staining. The results showed that MMP-2, MMP-9, and StAR were significantly expressed in the granulosa and thecal cells of the ovarian atretic follicles during proestrus, and were strongly expressed in the corpus luteum during metestrus.

Protective effect of magnesium and metformin on endometrium and ovary in experimental diabetes mellitus.

We evaluated the effect of magnesium and metformin on streptozotocin (STZ)-induced diabetes mellitus (DM) in non-pregnant female rats. The study comprised four groups, each consisting of eight, non-pregnant, adult Wistar female rats with a weight range of 170-250 g, maintained under the usual laboratory conditions. One group of female rats was the control group that received no treatment. To induce DM, the other three groups of animals received streptozotocin (STZ), 60 mg/kg i.p. (in a single dose). The first STZ group received no additional treatment. The second group received MgCl2 1 mmol/kg/day i.p. daily, for eight weeks. The third group received daily metformin, 100 mg/kg/day per os (endogastric probe), for eight weeks. Blood glucose, total plasma magnesium concentrations, and oxidative status were determined prior to, 24 hours and eight weeks after administration of the STZ. After eight weeks of treatment, the animals were anesthetized and sacrificed. The uterus and ovaries were removed and examined under optical microscopy. The data obtained were analyzed statistically using the ANOVA test. The results showed that the number of atretic ovarian follicles was 84%higher in the STZ-induced diabetes group compared to the control group (p<0.01). The number of atretic follicles found in the group receiving daily MgCl2 was 32% higher compared to the untreated control group (p<0.05). The number of atretic follicles was increased by only 27% in the metformin-treated group, as compared with the untreated control group.. The STZ-induced diabetes group presented an endometrial epithelial atrophy not seen in the control group. MgCl2 administration attenuated the degree of endometrial atrophy, there being an endometrial epithelial thickness of 19.43 ± 0.51 μm in the STZ+MgCl2 group (p<0.05), as compared to a thickness of 13.51 ± 0.27 μm in the STZ only-treated diabetic group.

Histological and immunohistochemical study of apoptosis in granulosa cells of atretic ovarian follicles of adult albino rat

Histological and immunohistochemical study of apoptosis in granulosa cells of atretic ovarian follicles of adult albino rat

Investigating the use of plasma testosterone and estradiol-17β to detect ovarian follicular atresia in farmed white sturgeon, Acipenser transmontanus

To improve quality and yield of caviar in farmed white sturgeon it is essential to correctly assess the stage of ovarian maturity and avoid harvesting females with atretic ovarian follicles. To detect atresia by changes in blood plasma sex steroids, individual females (N = 10) in the late phase of oogenesis were repeatedly bled and their ovaries biopsied before and after onset of ovarian atresia. Follicular atresia was induced by transferring females from cold (10–13 °C) to warm water (20 °C). Ovarian follicle diameter increased and oocyte polarization index decreased in sampled fish over time. Plasma testosterone concentrations in fish with normal follicles were significantly higher, compared to fish with early histological signs of follicular atresia, such as structural changes in the chorion. Plasma estradiol concentrations declined to below detection limit prior to histological signs of atresia in 55% of the fish. Ninety five percent of fish with normal ovarian follicles and 93% of fish with atretic ovarian follicles were correctly classified using a discriminant function analysis based upon plasma testosterone concentrations. Logistic regression models were developed to predict the probability of normal ovaries based on plasma concentrations of sex steroids and can be further refined to improve selection of fish with normal ovaries for caviar harvest.