Rabbit Ovary Research Articles

Tribulus terrestris Alters the Expression of Growth Differentiation Factor 9 and Bone Morphogenetic Protein 15 in Rabbit Ovaries of Mothers and F1 Female Offspring.

Although previous research has demonstrated the key role of the oocyte-derived factors, bone morphogenetic protein (BMP) 15 and growth differentiation factor (GDF) 9, in follicular development and ovulation, there is a lack of knowledge on the impact of external factors, which females are exposed to during folliculogenesis, on their expression. The present study investigated the effect of the aphrodisiac Tribulus terrestris on the GDF9 and BMP15 expression in the oocytes and cumulus cells at mRNA and protein levels during folliculogenesis in two generations of female rabbits. The experiment was conducted with 28 New Zealand rabbits. Only the diet of the experimental mothers group was supplemented with a dry extract of T. terrestris for the 45 days prior to insemination. The expression of BMP15 and GDF9 genes in the oocytes and cumulus cells of mothers and F1 female offspring was analyzed using real-time polymerase chain reaction (RT-PCR). The localization of the GDF9 and BMP15 proteins in the ovary tissues was determined by immunohistochemical analysis. The BMP15 and GDF9 transcripts were detected in the oocytes and cumulus cells of rabbits from all groups. T. terrestris caused a decrease in the BMP15 mRNA level in the oocytes and an increase in the cumulus cells. The GDF9 mRNA level increased significantly in both oocytes and cumulus cells. The downregulated expression of BMP15 in the treated mothers’ oocytes was inherited in the F1 female offspring born to treated mothers. BMP15 and GDF9 show a clearly expressed sensitivity to the bioactive compounds of T. terrestris.

Ellagitannins--compounds from pomegranate as possible effector in steroidogenesis of rabbit ovaries.

This study has observed possible effect of ellagitannins - compounds from pomegranate on process of steroidogenesis in ovaries. The aim of the study was to investigate the possible effect of punicalagin on secretion of steroid hormones - progesterone, androstenedione, testosterone and 17beta-estradiol by ovarian fragments of rabbits in vitro. Ovarian fragments from sexually mature female New Zealand white rabbits (n=20) were incubated without (control group) or with punicalagin at various doses 1, 10 and 100 microg.ml(-1) for 24 h. Hormones were evaluated by ELISA (The Enzyme-Linked Immunosorbent Assay). Data showed that progesterone and 17beta-estradiol (but not androstenedione and testosterone) release by rabbit ovarian fragments was significantly affected by punicalagin addition at various doses. Punicalagin (at 100 microg.ml(-1)) significantly (P<0.05) increased progesterone secretion. On the other hand, the release of 17beta-estradiol was significantly (P<0.005) decreased by punicalagin addition (at 10 microg.ml(-1)). Our results suggest that punicalagin could have dose-dependent impact on secretion of steroid hormones progesterone and 17beta-estradiol by rabbit ovarian fragments and it may be effector in process of ovarian steroidogenesis.

Estudios sobre los mecanismos inmunológicos de la infertilidad

Es posible producir en conejas, anticuerpos antiseminales capaces de causar infertilidad de origen inmunológico. La ovulación y fertilización en conejas inmunizadas se produce normalmente hasta la tercera división celular. La alteración del mecanismo de concepción estaría en la etapa de preimplantación o implantación inicial. Esto inmunidad es relativa, temporal y por el momento no es de alto grado de protección anticonceptiva. No se ha observado efecto teratogénico en los animales que nacieron de conejas inmunizadas.

Induction of ovulation in rabbits by adding Lecirelin to the seminal dose: In vitro and in vivo effects of different excipients

This study evaluates the effect of Lecirelin (Dalmarelin®, Fatro, Italy) diluted in different excipients (benzilic alcohol, benzoic acid and paraben) added to a seminal dose on LH concentrations, progesterone concentrations and ovarian status in rabbits. The in vitro effect on spermatozoa was also tested. A total of 100 multiparous female rabbits were divided into 5 groups, which at the moment of AI, received 0.2mL (5μg/dose) intramuscular (im) inoculation of Lecirelin (control) or the same Lecirelin dose administered intravaginally (iv) with the seminal dose alone (Lecirelin group) or with benzilic alcohol (Lecirelin BA group), benzoic acid (Lecirelin BAc group) or parabens (Lecirelin PA group) as an excipient. After 7 days, 10 rabbits per group were euthanized to analyze their ovarian status. In the control group, a high LH peak was detected 30min post AI, while in the iv groups a slight increase in LH occurred after 120min. The ovulation and fertility rate was similar in control and Lecirelin groups, while the lowest fertility rate was detected in the Lecirelin BA group. In a second experiment, the semen samples collected from male rabbits were diluted in TALP (control) or mixed with the 5μg of Lecirelin solutions used in the first experiment. The highest percentage of capacitated sperm (68.3%) was recorded in the Lecirelin PA. The lowest percentages were observed in the Lecirelin BA and BAc groups. In conclusion, the iv administration of Lecirelin represents an alternative method for simplifying rabbit insemination procedures.

In vivo imaging in the rabbit as a model for the study of ovulation-inducing factors

The study of factors responsible for eliciting ovulation in rabbits has been hampered by the lack of a suitable method of monitoring the ovaries invivo. Ovarian imaging by ultrasound biomicroscopy was used in two experiments designed to determine the effects of seminal plasma on the ovulatory response in rabbits. In Experiment 1, female rabbits were group-housed and treated intramuscularly with saline, gonadotropin releasing hormone (GnRH), or seminal plasma of llamas or rabbits (n = 4 to 6 per group). Rabbits were euthanized eight days later to evaluate the ovarian response by ultrasound biomicroscopy ex situ. No differences among groups were detected in the proportion of rabbits that ovulated or in the number and size of corpora lutea. The high incidence of ovulation in the negative control group was unexpected, and confounded determination of an ovulation-inducing effect of seminal plasma. In Experiment 2, female rabbits were caged individually, and treated as in Experiment 1 (n = 5 to 7 per group). The ovarian response was evaluated invivo by transcutaneous ultrasound biomicroscopy. Ovulation and formation of corpora lutea were detected only in rabbits given GnRH. A preovulatory surge in plasma luteinizing hormone concentration and a post-ovulatory rise in plasma progesterone concentration were detected only in rabbits treated with GnRH. Surgical translocation of the ovaries to a subcutaneous position enabled longitudinal assessment of the ovulatory response by ultrasound biomicroscopy. Results clearly documented the effect of physical/social interaction on ovulation in rabbits, and did not support the hypothesis that seminal plasma elicits ovulation in rabbits.

Effects of Crude Aqueous Extract of Origanum vulgaris in Developing Ovary of Rabbits Following in Utero, Adolescent, and Postpubertal Exposure

We evaluated the impact on rabbits after having been treated with Origanum vulgaris (Lamiaceae) (OV) at a dose level known to adversely affect ovarian functions in rodents without causing systemic toxicity. The choice of rabbits has been guided by the fact that rabbits have a relatively long phase of reproductive development and hence simulation of reproductive development is better as opposed to dealing with rodents. The use of rabbits facilitates multiple evaluations of mating ability. An attempt has also been made at determining whether OV affected ovarian development and hence the use of animal model. Rabbits were exposed to 80 mg OV/kg/day in utero (gestation days [GD] 0 to23) or during adolescence (postnatal weeks [PNW] 4 by breast feeding and orally from 4w to 12 w), and the offspring were examined at the end of the 12 W period. Another group was treated after puberty (for 12 weeks) till age of 24 [PNW] of age and examined at the conclusion of exposure and follicles were categorized as primordial, primary, small preantral, large preantral or small antral follicles. The most pronounced reproductive effects were in female rabbits group which had been exposed from in utero till post-puberty period, in weights of ovaries (at 12 and 24 weeks, down 23%; p < 0.05). Serum Gonadotropin levels were down (at 24 weeks, 32%; p < 0.05); a slight increase in histological alterations of the ovaries (p < 0.05) at 24 weeks, of abnormal follicles;Â

Farnesoid X receptor immunolocalization in reproductive tissues of adult female rabbits

Farnesoid X receptor (FXR) has been involved in lipid metabolism, cell proliferation, apoptosis, and aromatase expression, as well as in the steroid synthesis and signaling. Considering that these events occur in reproductive tissues in females, the aim of the present study was to determine the immunolocalization of FXR in the ovary, oviduct, uterus, and vagina of rabbits. Rabbits were sacrificed and their reproductive tissues were excised and histologically processed. Immunohistochemistry for FXR was done and reproductive tissues were photographed. FXR immunoreactivity was found in all types of ovarian follicles, ovarian stroma, and corpus luteum of virgin and pregnant rabbits. Also, oviductal and vaginal epithelium of virgins, as well as the oviductal smooth muscle, showed anti-FXR immunoreactivity. The uterine epithelium and musculature of virgins had scarce anti-FXR immunoreactivity. Although the role of FXR in female reproductive tissues is still not known, it is possible to consider various functions related to the reproductive tissue.

Expression pattern of Toll-like receptors (TLRs) in different organs and effects of lipopolysaccharide on the expression of TLR 2 and 4 in reproductive organs of female rabbit

Toll-like receptors (TLRs) are vital for innate immunity, and they were expressed in various immune cells, tissues and organs. Moreover, TLRs specific expression pattern in different cells, tissue and organs have been confirmed to have correlation with the ability to resistance to pathogenic challenges. The present study aimed to determine the expression profiles and levels of TLR2, 3, 4, 5, 6, 8 and 10 in the lung, trachea, intestine, stomach, liver, spleen, uterine horn and body, cervix, ovary, oviduct and hypothalamus of female rabbits, and whether the expression level of TLR2 and 4 in the ovary, oviduct, uterine horn and body, and cervix were affected by lipopolyasaccharide (LPS). The tissues of the lung, trachea, intestine, stomach, liver, spleen, uterine horn and body, cervix, ovary, oviduct and hypothalamus were collected from four rabbits which didn’t be treated as 0h. 16 rabbits in LPS group were injected with LPS (according to 0.5mg/kg body weight) and 16 rabbits in control group were injected with saline (LPS carrier), hereafter the tissues of the uterine horn and body, cervix, ovary and oviduct from 32 rabbits were collected after 1.5, 3, 6, and 12h (n=4 each group) postinjection. The expression profiles of TLRs were analyzed by reverse transcriptase polymerase chain reaction (RT-PCR), and expression level of TLRs were examined using quantitative real-time PCR (qRT-PCR). The results shown: TLR2, 3, 4, 5, 6, 8 and 10 were expressed in lung, trachea, intestine, stomach, liver, spleen, uterine horn and body, cervix, ovary, oviduct and hypothalamus of female rabbits, but their expression level had great difference in the same organs, and each TLR has different expression level in the different organs. After LPS-stimulation, the expression of TLR2 in the uterine body and horn was significantly higher than that in control group by 3h and 12h of postinjection (P<0.05) respectively. The expression of TLR4 in ovary and uterine body was significantly higher than that in control group by 3 and 12h of postinjection (P<0.05), and the expression of TLR4 in uterine body was greater than that in control by 3h postinjection (P<0.05). The results suggested LPS upregulated the expression of TLR2 and 4 in uterine body and horn, and the expression of TLR4 in ovary.

Production of somatic cell nuclear transfer embryos using in vitro-grown and in vitro-matured oocytes in rabbits

We examined growing oocytes collected from follicles remaining in superovulated rabbit ovaries, that were grown (in vitro growth, IVG) and matured (in vitro maturation, IVM) in vitro. We produced somatic cell nuclear transfer (SCNT) embryos using the mature oocytes and examined whether these embryos have the ability to develop to the blastocyst stage. In addition, we examined the effects of trichostatin A (TSA), a histone deacetylase inhibitor (HDACi), on the developmental competence of SCNT embryos derived from IVG-IVM oocytes. After growth for 7 days and maturation for 14-16 h in vitro, the growing oocytes reached the metaphase II stage (51.4%). After SCNT, these reconstructed embryos reached the blastocyst stage (20%). Furthermore, the rate of development to the blastocyst stage and the number of cells in the blastocysts in SCNT embryos derived from IVG-IVM oocytes were significantly higher for TSA-treated embryos compared with TSA-untreated embryos (40.6 versus 21.4% and 353.1 ± 59.1 versus 202.5 ± 54.6, P < 0.05). These results indicate that rabbit SCNT embryos using IVG-IVM oocytes have the developmental competence to reach the blastocyst stage.

English

Crude oil is found in water and soil due to pollution resulting from oil exploration and exploitation. It is used as traditional medicine in some countries, especially among rural dwellers in the south-south and south-eastern Nigeria. The aim of this study was to investigate the effects of Escravos crude oil on serum cholesterol, estradiol and progesterone in the ovary of Chinchilla rabbits. A total of thirty female Chinchilla rabbits of age twelve to fourteen weeks and weighing 1.2 to 1.45 kg were used. Crude oil was orally given at the dose of 15, 20, 25 and 30 mg/kg body weight, corresponding to groups B, C, D and E, respectively for 28 days while group A was the Control. The results showed a significant increase in serum levels of estradiol, cholesterol and ovary weight (p &lt; 0.05) while a significant decrease in serum level of progesterone (p &lt; 0.05) was observed. The histological findings include: ovarian cysts, fibrosis, marked lymphocytic infiltrations and hydropic cells. Therefore, Escravos crude oil could be considered as a potential endocrine disruptor which can affect the tissue architecture and the endocrine functions of the ovary. Key words: Chinchilla rabbits, Escravos crude oil, estradiol, fibrosis, hydropic cells, progesterone, ovarian cysts, total cholesterol.

Aminopeptidase activity in seminal plasma and effect of dilution rate on rabbit reproductive performance after insemination with an extender supplemented with buserelin acetate

Ovulation induction in artificially inseminated rabbits by adding GnRH synthetic analogues in the seminal doses is a welfare-orientated method to induce ovulation in rabbits and could have some advantages in field practice. This study was conducted to determine the effect of male genotype on the aminopeptidase activity in rabbit seminal plasma and the effects of dilution rate of semen on availability and reproductive performance when buserelin acetate is added to the seminal dose. To study the aminopeptidase activity, 12 mature bucks belonging to a paternal line and 12 from a maternal line were used. The bucks from the paternal line were used to study the effect of dilution rate on the availability of buserelin acetate after 2 hours of dilution and on the reproductive performance of the doses after artificial insemination of 389 commercial crossbreed does. Aminopeptidase activity in seminal plasma is dependent on the male genotype. The paternal line resulted 27% more aminopeptidase activity than the maternal line (P < 0.05). On the other hand, semen diluted 1:20 exhibited a marked increase in the availability of buserelin acetate and the fertility in this group was significantly higher than females from dilution rate 1:5 group, which showed similar results to that of the negative control group (does inseminated with semen diluted 1:20 in non–GnRH-supplemented extender). We conclude that the bioavailability of buserelin acetate when added to the seminal dose appears to be determined by the activity of the existing aminopeptidases and is consequently affected by the dilution rate used to prepare the artificial insemination doses.

Immunolocalization of GnRHRI, gonadotropin receptors, PGR, and PGRMCI during follicular development in the rabbit ovary

The aim of this study was to investigate the presence and localization of gonadotropin-releasing hormone receptor-I (GnRHRI), gonadotropin receptors (FSHR, LHR), progesterone receptor (PGR), and progesterone receptor membrane-binding component-I (PGRMCI) in the different developmental stages of the rabbit follicle. The ovaries were collected from four healthy New Zealand white rabbits, and the mRNA expression and protein levels of GnRHRI, FSHR, LHR, PGR, and PGRMCI were examined with real-time PCR and immunohistochemistry. The results showed that GnRHRI, FSHR, LHR, PGR, and PGRMCI mRNA was expressed in the ovary; furthermore, we show cell-type specific and follicular development stage-specific expression of these receptors at the protein level. Specifically, all of the receptors were detected in the oocytes from the primordial to the tertiary follicles and in the granulosa and theca cells from the secondary and tertiary follicles. In the mature follicles, all receptors were primarily localized in the granulosa and theca cells. In addition, LHR was also localized in the granulosa cells from the primordial and primary follicles. With follicular development, the expression level of all of the receptors, except GnRHRI, in the follicles showed a tendency to decrease because the area of the follicle increased sharply. The expression level of GnRHRI, FSHR, and PGR in the granulosa and theca cells showed an increasing trend with ongoing follicular development. Interestingly, the expression level of FSHR in the oocytes obviously decreased from the primary to the tertiary follicles, whereas LHR in the oocytes increased from the secondary to tertiary follicles. In conclusion, the expression of GnRHRI, the gonadotropin receptors, PGR, and PGRMCI decreased from the preantral follicles (primordial, primary, and secondary follicles) to the tertiary follicles. The expression of GnRHRI and LHR in the oocytes increased from the secondary to the tertiary follicles, whereas FSHR decreased from the primary to the tertiary follicles. The expression of GnRHRI and PGR in the granulosa and theca cells increased from the secondary to the mature follicles. These observations suggest that these receptors play roles in follicular development and participate in the regulation of follicular development.

Proliferation and apoptosis in the rabbit ovary after administration of T-2 toxin and quercetin

Proliferation and apoptosis in the rabbit ovary after administration of T-2 toxin and quercetin

Histological study of ovary through last periods( Oryctolagus cuniculus) of pregnancy in domestic rabbit

The aim of this work was to study the morphology of the ovaries of rabbit at last peroid pregnancy in order to understand the effect of pregnancy on the development of follicles. Twenty local breed pregnant does in estimated ages, five does prepared for every stage beginning from 22, 24, 26 and 30 days by which gestation occurred. Their ovaries were removed, fixed in 10% of formalin and routinely processed of histotechnique for histological studies. The observations of histological examination shown that the cortex was occupied with different types and various sizes of follicles, Corpora lutea were also observed in ovary at each stage of present study. These results show, and according statistical analyses of the numbers of primordial and primary follicles become decrease with progressive of pregnancy. The diameter of primary follicles can be different according to the average diameter of the oocyte. The results showed that decrease rate of secondary follicles formation through all pregnancy stages of present work compare with the rate of primary follicles. The ratio of follicles growth to atresia folliclea in pregnancy is lower than that of the female at cycle stages. The morphometerical result showed that the increase in rate of the tertiary follicles in last day of gestation.

A comparative study between bilateral ligation of the ovarian and the uterine arteries on the structure and function of the ovary of adult white rabbit

A comparative study between bilateral ligation of the ovarian and the uterine arteries on the structure and function of the ovary of adult white rabbit

Surgical translocation and ultrasound bio-microscopy of the ovaries in rabbits

Experiments were designed to validate the use of ultrasound bio-microscopy (UBM) as a method for assessing ovarian structures in rabbits. In Experiment 1, female New Zealand White (NZW) rabbits (n=4) were given an ovulation-inducing treatment and the ovaries were examined ex situ by UBM using a 25MHz oscillating sector transducer before being processed for histology. Pairwise correlations revealed strong relationships between UBM and histology in the number (Mean±SEM) of follicles =0.6mm (17.3±2.3 compared with19.0±1.6, respectively; r=0.96; P=0.040), CL (8.5±2.9 compared with 8.8±3.0; r=0.99; P=0.003), the diameter of follicles (1.1±0.05 compared with 1.1±0.03mm; r=0.96; P=0.035) and CL (2.1±0.7 compared with 1.8±0.6mm, r=0.99; P<0.001). In Experiment 2, the ovaries of NZW rabbits (n=12) were surgically translocated to a subcutaneous position in the flank region to permit serial examination of ovarian structures in vivo by UBM. Beginning 2 weeks after surgery, the ovaries were examined by UBM daily for at least 18 days, and again 2 months after surgery. Post-operative complications were minor, and both ovaries of each rabbit were identified consistently. The number and diameter of follicles =0.6mm were readily visualized during each examination. Multiple corpora lutea were detected in two rabbits, and serial follicular and luteal dynamics in these two rabbits were used to document the consistency of UBM and the retention of ovarian function after surgery. It is concluded that UBM is a valid tool for instant assessment of rabbit ovarian structures (follicles, corpora lutea, and cumulus-oocyte complexes) ex situ, and for serial assessment in vivo using a transcutaneous approach. Surgical translocation had no apparent untoward effect on ovarian function.

Rabbit zona pellucida composition: A molecular, proteomic and phylogenetic approach

The zona pellucida (ZP) participates in sperm-egg interactions during the first steps of fertilization. Recent studies have shown that the ZP matrix of oocytes in several species is composed of four glycoproteins, designated as ZP1, ZP2, ZP3 and ZP4, rather than the three described in mouse, pig and cow. In this study, investigations were carried out to unveil a fourth glycoprotein in the rabbit (Oryctolagus cuniculus) ZP. Using total RNA isolated from rabbit ovaries, the complementary deoxyribonucleic acid (cDNA) encoding rabbit ZP1 was amplified by reverse transcribed polymerase chain reaction (RT-PCR). The ZP1 cDNA contains an open reading frame of 1825 nucleotides encoding a polypeptide of 608 amino acid residues. The deduced amino acid sequence of rabbit ZP1 showed high identity with other species: 70% identity with human and horse ZP1, and 67% identity with mouse and rat ZP1. At the proteomic level, peptides corresponding to the four proteins were detected by mass spectrometry. In addition, a molecular phylogenetic analysis of ZP1 showed that pseudogenization of this gene has occurred at least four times during the evolution of mammals. The data presented in this manuscript provide evidence, for the first time, that the rabbit ZP is composed of four glycoproteins.

132 A NEW APPROACH TO ASSESS OVARIAN STRUCTURES IN LIVE RABBITS: SURGICAL TRANSLOCATION AND ULTRASOUND BIOMICROSCOPY

For the purpose of determining factors associated with ovulation induction in rabbits, there is a need to examine the ovaries in a serial fashion. To this end, a study was designed to develop an approach that would permit serial evaluation of ovarian structures in vivo using ultrasound biomicroscopy (UBM) while preserving ovarian function in rabbits. The use of UBM has enabled characterisation of ovarian dynamics in live mice and has recently been validated for assessing structures in excised rabbit ovaries (Cervantes et al. 2011 Reprod. Fertil. Dev. 23, 183–184). However, acoustic impedance of the body wall prevented acquisition of high-quality ovarian images in vivo by transabdominal UBM in rabbits. Female New Zealand White rabbits (5 months old; n = 12) underwent surgical ovarian translocation. Each ovary was exteriorized through a lateral flank incision on the respective sides, without compromising vascular supply. The mesovarium at each pole of the ovary was transfixed to the muscle layers of the abdominal wall to keep the ovary in a subcutaneous position. Finally, the subcutaneous and skin layers were closed. No postoperative complications were observed. The surgical site was allowed to heal for 2 weeks and the skin sutures were removed before UBM was attempted. The rabbits were wrapped in a towel for restraint without sedation. Acoustic gel was applied to the shaved skin over the translocated ovary and ovarian structures were imaged transcutaneously by UBM using a 25-MHz transducer on 3 consecutive days. Both ovaries were clearly distinguished in all 12 rabbits during each examination. Antral follicles ranging from 0.6 to 3.1 mm were detected and the number of follicles ≥0.6 mm per pair of ovaries ranged from 7 to 18. Data were analysed by one-way ANOVA. The number and diameter of follicles ≥0.6 mm per rabbit did not differ among the 3 examinations (mean ± s.e.m.; 11.0 ± 0.82, 11.8 ± 0.85 and 12.3 ± 0.75 follicles and 1.3 ± 0.07, 1.3 ± 0.07 and 1.4 ± 0.07 mm, respectively). However, follicles ≥2 mm in diameter were detected in 3 out of 12 rabbits on the first and second days and in 5 out of 12 rabbits on the third day. One or more corpora lutea were detected in the same 2 rabbits (2/12) during each of the 3 examination days. Two months after surgery, ovarian structures were clearly discernible by UBM in 11 of 24 translocated ovaries. Image deterioration was attributed to the attenuation of sound waves associated with increased skin thickness and growth of subcutaneous fat and connective tissue around the ovary, assessed at necropsy. In summary, translocated ovaries continued to function in their new location and transcutaneous UBM permitted serial visualisation of ovarian structures in live rabbits. Therefore, this new approach provides a nonterminal alternative for repetitive examination of rabbit ovaries and is particularly appropriate for experiments involving factors associated with ovulation induction in rabbits. This research was supported by the Natural Sciences and Engineering Research Council of Canada.

Role of rabbit prostate granules on sperm viability and acrosome reaction evaluated with different methods

In the present study, the role of rabbit seminal granules was observed. Their influence on motility, capacitation and acrosome reaction, as well as the presence of apoptosis and the morphology of rabbit sperm, were compared in different conditions. Ejaculated sperm from five mature New Zealand White rabbit bucks during three series of collections were studied, comparing raw semen, Percoll-selected sperm and Percoll-selected sperm plus prostate granules. We observed sperm motility kinetic traits by computer-assisted sperm analyzer (CASA) analysis in each sample. Acrosome status was evaluated by FITC-labeled Pisum sativum Agglutinin staining and chlortetracycline fluorescence assay, phosphatidylserine translocation was determined by AnnexinV/Propidium iodide assay and sperm morphology was studied using transmission electron microscopy (TEM). All traits were observed after 30 min incubation at 37 °C in 5% CO2. Data showed that sperm motility and viability markedly improved in the presence of prostate granules, whereas capacitation, acrosome reaction and phosphatidylserine translocation were lowered. TEM confirmed these results. In conclusion, the role of granules was confirmed in synchronizing sperm capacitation and acrosome reaction with egg availability; indeed, rabbit ovulation occurs only 6 to 10 h after mating.

Role of angiotensin in ovarian follicular development and ovulation in mammals: a review of recent advances

Angiotensin (Ang) II is widely known for its role in the control of systemic blood vessels. Moreover, Ang II acts on the vascular control of ovarian function, corpus luteum formation, and luteolysis. Over the past 10 years, our research group has been studying the new concept of the renin-angiotensin system (RAS) as an autocrine/paracrine factor regulating steroidogenesis and promoting different cellular responses in the ovary, beyond vascular function. We have developed and used different in vivo and in vitro experimental models to study the role of RAS in the ovary and a brief overview of our findings is presented here. It is widely accepted that there are marked species differences in RAS function in follicle development. Examples of species-specific functions of the RAS in the ovary include the involvement of Ang II in the regulation of follicle atresia in rats vs the requirement of this peptide for the dominant follicle development and ovulation in rabbits and cattle. More recently, Ang-(1-7), its receptor, and enzymes for its synthesis (ACE2, NEP, and PEP) were identified in bovine follicles, implying that Ang-(1-7) has an ovarian function. Other novel RAS components (e.g. (pro)renin receptor and renin-binding protein) recently identified in the bovine ovary show that ovarian RAS is poorly understood and more complex than previously thought. In the present review, we have highlighted the progress toward understanding the paracrine and autocrine control of ovarian antral follicle development and ovulation by ovarian tissue RAS, focusing on in vivo studies using cattle as a model.