Protective effect of kaempferol against cisplatin-induced acute ovarian damage in a mouse model / [Efeito protetor do kaempferol contra o dano ovariano agudo induzido pela cisplatina em um modelo murino]

The flavonoid kaempferol has attracted research attention as a potential adjuvant during chemotherapy. This study aimed to evaluate the protective effects of kaempferol against ovarian damage in cisplatin-treated mice. Two groups of mice received saline solution (intraperitoneal injection [i.p.]; control) or a single dose of cisplatin (5 mg/kg body weight, i.p.). Moreover, two other mice groups were pretreated with kaempferol (1 or 10 mg/kg body weight, i.p.) 30 min before of the cisplatin administration. Thereafter, their ovaries were harvested and subjected to histological (follicular morphology and activation) and fluorescence (reactive oxygen species [ROS] production, glutathione [GSH] concentration, and mitochondrial activity) analyses. Compared with cisplatin treatment alone, pretreatment with 1 mg/kg kaempferol maintained normal follicular morphology, reduced ROS production and mitochondrial damage, and enhanced GSH concentration. However, pretreatment with 10 mg/kg kaempferol did not prevent cisplatin-induced damage. The rate of primordial follicle activation was greater in mice pretreated with 1 mg/kg kaempferol than in the other treatment groups. In conclusion, pretreatment with 1 mg/kg kaempferol prevents cisplatin-induced ovarian damage and stimulates primordial follicle activation in mice.

O flavonoide kaempferol tem atraído a atenção como um potencial adjuvante durante a quimioterapia. O presente estudo objetivou avaliar os efeitos do kaempferol contra os danos ovarianos em camundongos tratados com cisplatina. Fêmeas de camundongos receberam solução salina (injeção intraperitoneal [ip]; controle) ou uma dose única de cisplatina (5 mg/kg, ip) ou foram pré-tratadas com kaempferol (1 ou 10 mg/kg, ip) 30 min antes da administração de cisplatina. Os ovários foram recuperados e destinados para as análises histológicas (morfologia e ativação folicular) e de fluorescência (produção de espécies reativas de oxigênio [ERO], concentração de glutationa [GSH] e atividade mitocondrial). Em comparação ao tratamento apenas com cisplatina, o pré-tratamento com 1 mg/kg de kaempferol manteve a morfologia folicular normal, reduziu a produção de ERO, bem como os danos mitocondriais, e aumentou a concentração de GSH. Entretanto, o pré-tratamento com 10 mg/kg de kaempferol não preveniu os danos induzidos pela cisplatina. A taxa de ativação do folículo primordial foi maior em camundongos pré-tratados com 1 mg/kg de kaempferol do que nos outros grupos experimentais. Em conclusão, o pré-tratamento com 1 mg/kg de kaempferol previne o dano ovariano induzido pela cisplatina e estimula a ativação do folículo primordial em camundongos.

Influence of the ovarian fragmentation before storage at 4o C on the apoptosis rates and in vitro development of ovine preantral follicles

The aim of this study was to evaluate the effect of ovarian tissue fragmentation before preservation at 4o C in MEM on the morphology, apoptosis, and growth of ovine preantral follicles. After collection, the ovaries were divided into two halves, being one divided into two fragments (1/4 of the ovary). One fragment was subdivided into two fragments (1/8), being one fixed for histology (fresh control). The remaining whole ovary, 1/2, 1/4 and 1/8 of the ovary were preserved in MEM at 4°C for 6, 12 or 24 h. The tissue was further destined to histology. In vitro culture and TUNEL technique were performed in treatments that showed the best results of follicular survival after preservation. Storage of 1/8 of the ovary increased the normal follicles compared with half or whole ovary. After preservation in 1/8 of the ovary and culture for 7 days, the percentage of apoptotic cells was similar to the fresh control and non-cultured fragments. The percentage of growing follicles increased after preservation of 1/8 of the ovary compared with 1/4. In conclusion, ovine preantral follicles can be preserved in fragments of 1/8 of the ovary in MEM at 4°C for 24 h, without affecting apoptosis and their ability to grow in vitro.

Influence of the ovarian fragmentation before storage at 4o C on the apoptosis rates and in vitro development of ovine preantral follicles

The aim of this study was to evaluate the effect of ovarian tissue fragmentation before preservation at 4o C in MEM on the morphology, apoptosis, and growth of ovine preantral follicles. After collection, the ovaries were divided into two halves, being one divided into two fragments (1/4 of the ovary). One fragment was subdivided into two fragments (1/8), being one fixed for histology (fresh control). The remaining whole ovary, 1/2, 1/4 and 1/8 of the ovary were preserved in MEM at 4°C for 6, 12 or 24 h. The tissue was further destined to histology. In vitro culture and TUNEL technique were performed in treatments that showed the best results of follicular survival after preservation. Storage of 1/8 of the ovary increased the normal follicles compared with half or whole ovary. After preservation in 1/8 of the ovary and culture for 7 days, the percentage of apoptotic cells was similar to the fresh control and non-cultured fragments. The percentage of growing follicles increased after preservation of 1/8 of the ovary compared with 1/4. In conclusion, ovine preantral follicles can be preserved in fragments of 1/8 of the ovary in MEM at 4°C for 24 h, without affecting apoptosis and their ability to grow in vitro.(AU)

Effect of ovarian tissue transportation in Amburana cearensis extract on the morphology and apoptosis of goat preantral follicles

The aim of the present study was to evaluate the effect of Amburana cearensis extract during caprine ovarian tissue transportation on the survival of preantral follicles in vitro. HPLC was used to determine the fingerprint chromatogram of the ethanolic extract. Five goat ovarian pairs were divided into fragments. One fragment was fixed for histology and TUNEL Analysis (fresh control). The other fragments were placed in MEM or A. cearensis extract (0.1; 0.2 or 0.4 mg/ml) and stored at 4oC for 6, 12 or 24 h. Preserved Fragments were also fixed for histology and TUNEL analysis. The presence of phenolic compounds (protocatechuic acid, epicatechin, p-coumaric acid, gallic acid and kaempferol) in the extract was confirmed using HPLC. Thepercentage of normal follicles preserved in 0.2 mg/ml A. cearensis for 6 h was similar to that observed in the fresh control. Moreover, the percentage of normal follicles was higher after preservation in 0.2 mg/ml A. cearensisFor 6 h than the other A. cearensis treatments and similar to that found in MEM. There were no differences in the percentage of apoptotic cells between fresh control and those preserved for 6 h in MEM or 0.2 mg/ml A. cearensis. In conclusion, both 0.2 mg/ml A. cearensis or MEM can be used for the preservation of goat preantral follicles for up to 6 h. The use of A. cearenses is recommended due to the higher cost of MEM.

Effect of ovarian tissue transportation in Amburana cearensis extract on the morphology and apoptosis of goat preantral follicles

The aim of the present study was to evaluate the effect of Amburana cearensis extract during caprine ovarian tissue transportation on the survival of preantral follicles in vitro. HPLC was used to determine the fingerprint chromatogram of the ethanolic extract. Five goat ovarian pairs were divided into fragments. One fragment was fixed for histology and TUNEL Analysis (fresh control). The other fragments were placed in MEM or A. cearensis extract (0.1; 0.2 or 0.4 mg/ml) and stored at 4oC for 6, 12 or 24 h. Preserved Fragments were also fixed for histology and TUNEL analysis. The presence of phenolic compounds (protocatechuic acid, epicatechin, p-coumaric acid, gallic acid and kaempferol) in the extract was confirmed using HPLC. Thepercentage of normal follicles preserved in 0.2 mg/ml A. cearensis for 6 h was similar to that observed in the fresh control. Moreover, the percentage of normal follicles was higher after preservation in 0.2 mg/ml A. cearensisFor 6 h than the other A. cearensis treatments and similar to that found in MEM. There were no differences in the percentage of apoptotic cells between fresh control and those preserved for 6 h in MEM or 0.2 mg/ml A. cearensis. In conclusion, both 0.2 mg/ml A. cearensis or MEM can be used for the preservation of goat preantral follicles for up to 6 h. The use of A. cearenses is recommended due to the higher cost of MEM.(AU)

Steady-state levels of vasoactive intestinal peptide (VIP) mRNA in goat ovaries and the effect of VIP on the in vitro development of isolated preantral follicles

The aims of this study were to verify the steady-state level of vasoactive intestinal peptide (VIP) mRNA in goat follicles at various developmental stages and to investigate the influence of VIP on the survival, antrum formation and growth of secondary follicles cultured for 6 days. Primordial, primary and secondary goat follicles and small and large antral follicles were obtained to quantify VIP mRNA by real-time reverse transcription with the polymerase chain reaction. The influence of VIP and the presence or absence of follicle-stimulating hormone (FSH) on the development of secondary follicles and on mRNA expression for VIP and FSH receptor (FSHR) were determined after 6 days of culture. Survival, antrum formation and follicular diameter were evaluated every other day of culture. The levels of VIP mRNA in primary and secondary follicles were significantly higher than in primordial follicles. Cumulus–oocyte complexes (COCs) from both small and large antral follicles had significantly higher levels ofVIP mRNA than their respective granulosa/theca cells. During culture, the addition of VIP and/or FSH had o effect on follicular development. However, the presence of FSH and/or VIP in the culture medium significantly reduced VIP mRNA levels, but did not alter FSHR mRNA levels. In conclusion, VIP mRNA was detected in all goat follicular categories and cellular types, VIP and/or FSH did not affect the development of secondary follicles and reduce the expression of VIP mRNA levels.(AU)

Steady-state levels of vasoactive intestinal peptide (VIP) mRNA in goat ovaries and the effect of VIP on the in vitro development of isolated preantral follicles

The aims of this study were to verify the steady-state level of vasoactive intestinal peptide (VIP) mRNA in goat follicles at various developmental stages and to investigate the influence of VIP on the survival, antrum formation and growth of secondary follicles cultured for 6 days. Primordial, primary and secondary goat follicles and small and large antral follicles were obtained to quantify VIP mRNA by real-time reverse transcription with the polymerase chain reaction. The influence of VIP and the presence or absence of follicle-stimulating hormone (FSH) on the development of secondary follicles and on mRNA expression for VIP and FSH receptor (FSHR) were determined after 6 days of culture. Survival, antrum formation and follicular diameter were evaluated every other day of culture. The levels of VIP mRNA in primary and secondary follicles were significantly higher than in primordial follicles. Cumulus–oocyte complexes (COCs) from both small and large antral follicles had significantly higher levels ofVIP mRNA than their respective granulosa/theca cells. During culture, the addition of VIP and/or FSH had o effect on follicular development. However, the presence of FSH and/or VIP in the culture medium significantly reduced VIP mRNA levels, but did not alter FSHR mRNA levels. In conclusion, VIP mRNA was detected in all goat follicular categories and cellular types, VIP and/or FSH did not affect the development of secondary follicles and reduce the expression of VIP mRNA levels.

Sphingosine 1-phosphate promotes activation of aprine preantral follicle in vitro / Esfingosina 1-fosfato promove ativação de folículos pré-antrais de caprinos in vitro

This study describes the effect of sphingosine 1-phosphate (S1P) for development of preantral follicle, therefore the activation and follicular viability of caprine follicles cultured in vitro. Ovarian fragments were cultured for 1 or 7 days in Minimum Essential Medium with different S1P concentrations (0, 1, 10, 50, 100 or 200ng/mL). All ovarian fragments were processed for histological analysis in optical microscopy, transmission electron microscopy and fluorescence analysis. The treatment using 1ng/mL of S1P was able to maintain the percentage of normal follicles with the progression of the culture from day 1 to 7. At end of the 7-day culture period there was a significant reduction (P<0.05) in the percentage of primordial follicles in all groups treated with S1P, compared with fresh control (FC) and Control Culture (CC), which was followed by an increase of activated follicles (intermediary, primary and secondary). In addition, the culture for 7 days with media supplemented with S1P with 1ng/mL preserved the ultrastructure of organelles and kept the preantral follicular viability when evaluated by fluorescence microscopy. In conclusion, after 7 days of culture, the 1ng/mL of S1P activates the development of preantral caprine follicles, cultured in situ and maintains the oocitary and follicular viability.(AU)

Este estudo descreve o efeito da esfingosina 1-fosfato (S1P) no desenvolvimento de folículos pré-antrais, portanto da ativação e viabilidade de folículos caprinos cultivados in vitro. Fragmentos de ovários foram cultivados por um ou sete dias em meio essencial mínimo com diferentes concentrações de S1P (0, 1, 10, 50, 100 ou 200ng/mL). Os fragmentos de ovário foram processados para análise histológica em microscopia óptica, microscopia eletrônica e microscopia de fluorescência. O tratamento usando 1ng/mL de S1P foi capaz de manter a porcentagem de folículos normais durante o período de cultivo de sete dias. Ao final do período de cultivo, houve uma redução significativa (p<0,05) na porcentagem de folículos primordiais em todos os grupos tratados com S1P, comparados com os grupos controle (FC e CC), seguida por um aumento do número de folículos ativados (intermediários, primários e secundários). Adicionalmente, na cultura por sete dias com meio suplementado com S1P (1ng/mL), houve preservação da ultraestrutura das organelas e manteve-se a viabilidade dos folículos pré-antrais avaliados por microscopia de fluorescência. Em conclusão, após sete dias de cultura, o meio suplementado com 1ng/mL de S1P ativa o desenvolvimento de folículos pré-antrais de caprino, cultivados in situ e mantém as viabilidades oocitária e folicular.(AU)

Transforming growth factor-β (TGF-β) maintains follicular ultrastructure and stimulates preantral follicle growth in caprine ovarian tissue cultured in vitro / Fator de crescimento transformante-β (TGF-β) mantém a ultraestrutura folicular e estimula o crescimento de folículos pré-antrais caprinos inclusos em tecido ovariano cultivado in vitro

The objectives of this study were to investigate whether TGF-β affect the survival, activation and further growth of goat primordial follicles enclosed in ovarian cortex after in vitro culture. Goat ovaries were collected from an abattoir and pieces of ovarian tissues were cultured for one or seven days in a supplemented alpha Minimum Essential Medium, alone or containing TGF-β (1, 5, 10 or 50ng/mL). Ovarian tissues from the fresh control as well as those cultured were processed for histological and ultrastructural studies. The results showed that when compared with fresh control, there was decrease in the percentages of histologically normal follicles in all treatments only after seven days culture. TGF-β did not affect the activation of preantral follicles regardless of its concentration, however, larger follicles diameter (P<0.05) was observed using 10ng/mL TGF-β than in the fresh control and other treatments. Moreover, this concentration maintained the normal ultrastructure after seven days of culture. In conclusion, TGF-β showed additional effect on the follicle growth and the maintenance of ultrastructural integrity of goat preantral follicles enclosed in ovarian tissue when used at 10ng/mL during seven days of culture.(AU)

O objetivo desse estudo foi investigar se o TGF-β afeta a sobrevivência, ativação e crescimento de folículos primordiais caprinos inclusos no córtex ovariano após o cultivo in vitro. Ovários de cabras foram coletados em abatedouro e fragmentos de tecido ovariano foram cultivados por um e sete dias em meio essencial mínimo alfa (α-MEM+) sozinho ou suplementado com TGF-β (1, 5, 10 ou 50ng/mL). Fragmentos ovarianos não cultivados e cultivados foram processados para análise histológica e ultraestrutural. Os resultados mostraram que, comparado ao controle fresco, houve diminuição no percentual de folículos morfologicamente normais em todos os tratamentos somente após sete dias de cultivo. O TGF-β não afetou a ativação folicular independente da concentração testada, contudo, o diâmetro folicular foi superior (P<0.05) no tratamento com 10ng/mL de TGF-β quando comparado ao controle fresco e aos demais tratamentos. Além disso, essa mesma concentração manteve a ultraestrutura normal dos folículos após sete dias de cultivo. Em conclusão, o TGF-β apresentou efeito adicional no crescimento folicular e na manutenção da integridade ultraestrutural de folículos pré-antrais caprinos inclusos no tecido ovariano quando utilizado na concentração de 10ng/mL durante sete dias de cultivo.(AU)

Involvement of vasoactive intestinal peptide (VIP) on ovarian physiology

In addition to the central nervous system, vasoactive intestinal peptide (VIP) containing nerves have been described throughout the female genital tract. VIP is reported to be produced by nerves fibers innervating follicles at all stages of development in rodents. There is growing evidence that VIP and their receptors play important roles in the local regulation of ovarian physiology mostly through cAMP pathway. It has been reported that VIP regulates the ovarian follicle survival and growth, oocyte maturation, ovulation and steroidogenesis. Studies also demonstrated that VIP inhibits apoptosis of rat follicles and is an important factor for the growth of preantral follicles enclosed in caprine ovarian tissue. Even though the addition of VIP to the culture medium did not improve in vitro maturation and fertilization of oocytes, it has been shown to stimulate ovulation in perfused rat ovaries. VIP is also involved in the regulation of steroidogenic activity. Therefore, this review aims to summarize current data on the importance of VIP on ovarian physiology.

Involvement of vasoactive intestinal peptide (VIP) on ovarian physiology

In addition to the central nervous system, vasoactive intestinal peptide (VIP) containing nerves have been described throughout the female genital tract. VIP is reported to be produced by nerves fibers innervating follicles at all stages of development in rodents. There is growing evidence that VIP and their receptors play important roles in the local regulation of ovarian physiology mostly through cAMP pathway. It has been reported that VIP regulates the ovarian follicle survival and growth, oocyte maturation, ovulation and steroidogenesis. Studies also demonstrated that VIP inhibits apoptosis of rat follicles and is an important factor for the growth of preantral follicles enclosed in caprine ovarian tissue. Even though the addition of VIP to the culture medium did not improve in vitro maturation and fertilization of oocytes, it has been shown to stimulate ovulation in perfused rat ovaries. VIP is also involved in the regulation of steroidogenic activity. Therefore, this review aims to summarize current data on the importance of VIP on ovarian physiology.(AU)

Ascorbic acid improve the survival and in vitro growth of isolated caprine preantral follicles

The present study aims to investigate the influence of two concentrations of ascorbic acid on the survival, growth , antral formation and m RNA expression of the matrix metalloproteinases - 9 (MMP - 9) and their tissue inhibitor - 2 (TIMP - 2) on caprine preantral follicles during long - term in vitro culture. Isolated preantral follicles were individ ually cultured without or with ascorbic acid at 50 μ g/ml (AA50) or 100 μ g/ml (AA100) during 18 days. The parameters evaluated were follicular viability, growth, antrum formation and extruded oocytes. The genes MMP - 9 and TIMP - 2 were quantified by real - time polymer ase chain reaction (qPCR) after 18 days of culture in the control medium (MEM + ) or ascorbic acid (50 or 100 μ g/ml) and in fresh control (non cultured) . At the end of culture, AA50 significantly increased the percentage of viable follicles compared w ith other treatments . Moreover, mean daily increase in follicular diameter (μm/day) was significantly higher in the presence of both concentrations of ascorbic acid than in MEM + alone. Higher rates of antral formation and lower percentages of extruded oocy tes were observed in medium containing AA50 compared with control medium. Real Time RT - PCR assays showed that AA50 increase s MMP - 9 expression significantly compared with fresh control and MEM + alone. In conclusion, ascorbic acid at 50 μ g/ml was very import ant for the maintenance of caprine preantral follicle viability and development after in vitro culture and influences in vitro the enzymes involved with basement membrane remodeling.

Ascorbic acid improve the survival and in vitro growth of isolated caprine preantral follicles

The present study aims to investigate the influence of two concentrations of ascorbic acid on the survival, growth , antral formation and m RNA expression of the matrix metalloproteinases - 9 (MMP - 9) and their tissue inhibitor - 2 (TIMP - 2) on caprine preantral follicles during long - term in vitro culture. Isolated preantral follicles were individ ually cultured without or with ascorbic acid at 50 μ g/ml (AA50) or 100 μ g/ml (AA100) during 18 days. The parameters evaluated were follicular viability, growth, antrum formation and extruded oocytes. The genes MMP - 9 and TIMP - 2 were quantified by real - time polymer ase chain reaction (qPCR) after 18 days of culture in the control medium (MEM + ) or ascorbic acid (50 or 100 μ g/ml) and in fresh control (non cultured) . At the end of culture, AA50 significantly increased the percentage of viable follicles compared w ith other treatments . Moreover, mean daily increase in follicular diameter (μm/day) was significantly higher in the presence of both concentrations of ascorbic acid than in MEM + alone. Higher rates of antral formation and lower percentages of extruded oocy tes were observed in medium containing AA50 compared with control medium. Real Time RT - PCR assays showed that AA50 increase s MMP - 9 expression significantly compared with fresh control and MEM + alone. In conclusion, ascorbic acid at 50 μ g/ml was very import ant for the maintenance of caprine preantral follicle viability and development after in vitro culture and influences in vitro the enzymes involved with basement membrane remodeling.(AU)

Sistemas de cultivo in vitro para o desenvolvimento de oócitos imaturos de mamíferos / Systems in vitro development of immature oocytes of mammalians

O ovário mamífero possui um grande estoque de folículos primordiais, que é uma fonte potencial de oócitos para a produção in vitro de embriões. Sendo assim, o desenvolvimento de sistemas de cultivo in vitro que explorem o grande número de oócitos imaturos oriundos de folículos pré-antrais de ovários mamíferos torna-se importante para maximizar o potencial reprodutivo das fêmeas. A presente revisão aborda os aspectos relacionados aos sistemas de cultivo in vitro para desenvolvimento de oócitos imaturos oriundos de folículos pré-antrais, bem como às técnicas para analisar sua eficiência. (AU)

The mammalian ovary has a large population of primordial follicles, which is a potential source of oocytes useful for embryo in vitro production. Due to this potential, the development of in vitro culture systems to exploit the large number of immature oocytes from the preantral follicles in the mammalian ovary becomes very important to maximize the female reproductive potential. The present review approaches related aspects of in vitro culture systems for the development of immature oocytes originated from the preantral follicles, as well the techniques to analyze their efficiency.(AU)

Sistemas de cultivo in vitro para o desenvolvimento de oócitos imaturos de mamíferos / Systems in vitro development of immature oocytes of mammalians

O ovário mamífero possui um grande estoque de folículos primordiais, que é uma fonte potencial de oócitos para a produção in vitro de embriões. Sendo assim, o desenvolvimento de sistemas de cultivo in vitro que explorem o grande número de oócitos imaturos oriundos de folículos pré-antrais de ovários mamíferos torna-se importante para maximizar o potencial reprodutivo das fêmeas. A presente revisão aborda os aspectos relacionados aos sistemas de cultivo in vitro para desenvolvimento de oócitos imaturos oriundos de folículos pré-antrais, bem como às técnicas para analisar sua eficiência.

The mammalian ovary has a large population of primordial follicles, which is a potential source of oocytes useful for embryo in vitro production. Due to this potential, the development of in vitro culture systems to exploit the large number of immature oocytes from the preantral follicles in the mammalian ovary becomes very important to maximize the female reproductive potential. The present review approaches related aspects of in vitro culture systems for the development of immature oocytes originated from the preantral follicles, as well the techniques to analyze their efficiency.

Expression of protein and mRNA encoding Insulin Growth Factor-I (IGF-I) in goat ovarian follicles and the influence of IGF-I on in vitro development and survival of caprine preantral follicles

The aim of this study was to investigate the protein and mRNA expression levels of IGF-I and the effects of IGF-I on preantral follicle survival and development, using an in vitro goat ovarian cortical culture system. The ovaries were used for immunohistochemical localization of IGF-I protein or used to demonstrate mRNA expression of IGF-I. For the latter goal, preantral and antral follicles, cumulus-oocyte complex, mural granulosa and theca cells were collected to study mRNA expression. For in vitro studies, ovarian cortex were cultured for 1 and 7 days with MEM supplemented IGF-I (0, 1, 10, 50, 100 or 200 ng/ml). Immunohistochemical results showed strong reactions for IGF-I in oocytes and granulosa cells of all follicular stages, except in granulosa cells of primordial and primary follicles. mRNA expression analysis demonstrated a discrete increase in the production of IGF-I during the transition from primordial to the primary and secondary follicle stages. After 7 days of culture, addition of 50 ng/ml of IGF-I to the medium showed the greatest percentage of normal follicles when compared with other concentrations. Furthermore, the highest percentage of primary follicles was observed after 7 days of culture in MEM+ plus 10 and 50 ng/ml of IGF-I. Culture of ovarian tissue for 7 days in MEM+ plus 50 ng/ml of IGF-I promoted the greatest increase (P < 0.05) in follicular diameter of all of the concentrations tested. In conclusion, IGF-I protein and mRNA were expressed in all follicular categories of goat. Furthermore, IGF-I maintained preantral follicle survival, promoted primordial follicle activation and stimulated the transition from intermediate to primary follicles.(AU)

Expression of protein and mRNA encoding Insulin Growth Factor-I (IGF-I) in goat ovarian follicles and the influence of IGF-I on in vitro development and survival of caprine preantral follicles

The aim of this study was to investigate the protein and mRNA expression levels of IGF-I and the effects of IGF-I on preantral follicle survival and development, using an in vitro goat ovarian cortical culture system. The ovaries were used for immunohistochemical localization of IGF-I protein or used to demonstrate mRNA expression of IGF-I. For the latter goal, preantral and antral follicles, cumulus-oocyte complex, mural granulosa and theca cells were collected to study mRNA expression. For in vitro studies, ovarian cortex were cultured for 1 and 7 days with MEM supplemented IGF-I (0, 1, 10, 50, 100 or 200 ng/ml). Immunohistochemical results showed strong reactions for IGF-I in oocytes and granulosa cells of all follicular stages, except in granulosa cells of primordial and primary follicles. mRNA expression analysis demonstrated a discrete increase in the production of IGF-I during the transition from primordial to the primary and secondary follicle stages. After 7 days of culture, addition of 50 ng/ml of IGF-I to the medium showed the greatest percentage of normal follicles when compared with other concentrations. Furthermore, the highest percentage of primary follicles was observed after 7 days of culture in MEM+ plus 10 and 50 ng/ml of IGF-I. Culture of ovarian tissue for 7 days in MEM+ plus 50 ng/ml of IGF-I promoted the greatest increase (P < 0.05) in follicular diameter of all of the concentrations tested. In conclusion, IGF-I protein and mRNA were expressed in all follicular categories of goat. Furthermore, IGF-I maintained preantral follicle survival, promoted primordial follicle activation and stimulated the transition from intermediate to primary follicles.

Regulation of ovarian folliculogenesis by Kit Ligand and the c-Kit system in mammals

The system comprised of Kit Ligand (KL) and its receptor c-Kit has proven to play a role in normal female reproduction and fertility in mammals. Gene expression studies have revealed that biological activities of ligands and receptors of the KL/c-Kit system are important in controlling apoptosis and cellular proliferation in reproductive tissues. Collectively, these studies have provided a better understanding of ovarian physiology and female fertility through the establishment of the concept that the KL/c-Kit system regulates the viability of primordial germ cells and follicles, initiation of primordial follicle growth, and further oocyte and follicular development through different signaling proteins. The purpose of this article is to review the importance of the KL/c-Kit system in ovarian follicular development, especially in the preantral phase of folliculogenesis.(AU)

Regulation of ovarian folliculogenesis by Kit Ligand and the c-Kit system in mammals

The system comprised of Kit Ligand (KL) and its receptor c-Kit has proven to play a role in normal female reproduction and fertility in mammals. Gene expression studies have revealed that biological activities of ligands and receptors of the KL/c-Kit system are important in controlling apoptosis and cellular proliferation in reproductive tissues. Collectively, these studies have provided a better understanding of ovarian physiology and female fertility through the establishment of the concept that the KL/c-Kit system regulates the viability of primordial germ cells and follicles, initiation of primordial follicle growth, and further oocyte and follicular development through different signaling proteins. The purpose of this article is to review the importance of the KL/c-Kit system in ovarian follicular development, especially in the preantral phase of folliculogenesis.

Papel do Hormônio Folículo Estimulante na foliculogênese in vivo e in vitro / Role of Follicle Stimulating Hormone in folliculogenesis in vivo and in vitro

A foliculogênese é controlada por diversos hormônios e fatores de crescimento, que sinergicamente agem regulando os eventos envolvidos na fisiologia da reprodução. Dentre esses hormônios, destaca-se o Hormônio Folículo Estimulante (FSH), que é uma gonadotrofina presente em todas as fases da foliculogênese, atuando de forma direta ou indireta para promover o desenvolvimento folicular in vivo e in vitro. Nesse contexto, a revisão irá abordar o papel do FSH na regulação da foliculogênese de mamíferos, bem como a influência das diferentes origens de FSH sobre o crescimento folicular in vivo e in vitro e o seu papel na reprodução assistida.(AU)

The foliculogenesis is controlled by various hormones and growth factors, which act synergistically to regulate the events involved in the physiology of reproduction. Among these hormones, the Follicle Stimulating Hormone (FSH) is a gonadotropin which is present in all stages of folliculogenesis, acting directly or indirectly to promote the follicular development in vivo and in vitro. In this context, the review will contribute to a better understanding of the role of FSH in the regulation of folliculogenesis of mammals as well as the influence of different sources of FSH on the follicular growth in vivo and in vitro and its role in assisted reproduction.(AU)