RESUMO
This study evaluated the effect of crude protein (CP) reduction in four diets (156, 139, 132, and 127 g Kg-1 DM) maintaining constant metabolizable protein (188 g/day) on the follicular fluid and cumulus-oocyte complexes of mid-lactating Girolando cows. Twenty-two Girolando cows with average of 21.55 ±3.19 L daily milk yield, 105.30 ±22.62 days in lactation and 3.22 ±0.03 body condition score were selected. To reduce CP in diets and maintain constant metabolizable protein, urea and soybean meal were gradually replaced by lignosulfonate-treated soybean meal (SoyPass®, Cargill), resulting in an increase in rumen-undegradable protein and a reduction in rumen degradable protein. A linear and quadratic reduction was observed in the plasma and follicular fluid urea nitrogen concentration following CP reduction, with the most intense reduction occurring in the 127 g Kg-1 DM group (p<0.001). As CP reduced, there was a tendency for a linear increase in the follicular growth rate (P=0.0696), on the number and proportion of viable oocytes (P<0.09), and also a linear increase for the number (P=0.0397) and proportion (P<0.09) of grade I viable oocytes. Plus, there was a linear effect for the number of cumulus oophorus cells. Cows fed with the lowest amount of CP had cumulus-oocyte complexes with higher numbers of cumulus oophorus cells (P=0.0238). Also, the reduction of diet crude protein was followed by a decrease in the probability of oocytes' DNA degradation. In conclusion, the reduction of CP in the diet of mid-lactating Girolando cows, reduces urea nitrogen concentration in both blood plasma and follicular fluid, and, as a consequence, increases the viability of oocytes and the number of cumulus oophorus cells while reducing oocytes' DNA degradation of follicular included cumulus-oocyte complex. The reduction on dietary CP may improve in vivo oocytes' embryo development impacting fertility of lactating dairy cows.(AU)
Assuntos
Animais , Feminino , Bovinos/fisiologia , Ingestão de Alimentos/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Oócitos/fisiologia , Lactação/fisiologia , Líquido Folicular/fisiologiaRESUMO
Durante a foliculogênese ovariana, cerca de 99,9% dos folículos morrem pelo processo de atresia folicular. O processo de atresia pode ocorrer pelas vias degenerativa ou apoptótica. Este processo compromete todos os estágios de desenvolvimento folicular, sendo os folículos antrais os mais afetados. Por outro lado, os folículos préantrais são mais resistentes, em função de sua menor taxa metabólica, bem como do número reduzido de células e camadas de células somáticas, células da granulosa e/ou da teca. Embora folículos pré-antrais sejam menos afetados pelo processo de atresia, quando este evento ocorre, pode-se classificá-lo de duas formas, degeneração do tipo I e degeneração do tipo II. Na degeneração do tipo I, o oócito é o compartimento mais comprometido, apresentando núcleo picnótico, embora suas células da granulosa apresentem-se bem organizadas e sem picnose nuclear. Já na degeneração do tipo II, os folículos apresentam oócito retraído e células da granulosa edemaciadas, desorganizadas e sem aderência à membrana basal e ao oócito. É importante destacar que a degeneração do tipo I é mais comum em folículos primordiais e primários, enquanto folículos secundários apresentam mais degeneração do tipo II, ou seja, a medida que os folículos evoluem, a degeneração do tipo II é mais frequente. Considerando todos os aspectos aqui relacionados, essa revisão de literatura abordará aspectos relacionados aos processos de foliculogênese e atresia folicular, bem como as substâncias que induzem a atresia durante a foliculogenese in vitro e in vivo e, ainda, os métodos e parâmetros para análise da atresia em folículos ovarianos. Isto se deve a necessidade de desenvolvimento de protocolos mais eficientes de recuperação dos folículos ovarianos, prevenindo essa grande perda folicular e otimizando as possibilidades de utilização desses materiais biológicos no futuro.
During ovarian foliculogenesis, about 99.9% of follicles die by the follicle atresia process. The atresia process can occur via degeneration or apoptosis. This process compromises all the follicle development stages, with antral follicles being those most affected. On the other hand, the preantral follicles are more residents, since their slow metabolic rate, as well as the reduced number and layers of somatic cells, granulosa and/or thecal cells. Although preantral follicles are less affected by the atresia process, when the event occurs, we can classify it in two ways, type I or type II degenerated follicles. In the type I degeneration the oocyte is the most compromised compartment, showing the picnotic nuclei, although its granulosa cells presented well organized and no picnosis. Already in the type II degeneration, the follicles presented shrunken in the oocyte, and swollen, disorganization and no adhered granulosa cells from the basal membrane and oocyte. It is important to highlight that type I degeneration is the most common in primordial and primary follicles, while in secondary follicles present more type II degeneration, which means that the as follicle evolve, type II degeneration is more frequent. Considering all the aspects related here, this literature review will address aspects related to the folliculogenesis and the process of follicle atresia, as well as substances that induce atresia during in vitro and in vivo folliculogenesis and methods and parameters for analyzing atresia in ovarian follicles. This is due to the need to develop more efficient ovarian follicle recovery protocols, which can prevent this great follicular loss and optimizing the possibilities of use of these biological materials in the future.
Assuntos
Animais , Vacúolos , Líquido Folicular/fisiologia , Atresia Folicular/fisiologia , Folículo Ovariano/crescimento & desenvolvimento , Mamíferos/crescimento & desenvolvimentoRESUMO
An equilibrium needs to be established by the cellular and acellular components of the ovarian follicle if developmental competence is to be acquired by the oocyte. Both cumulus cells (CCs) and follicular fluid (FF) are critical determinants for oocyte quality. Understanding how CCs and FF influence oocyte quality in the presence of deleterious systemic or pelvic conditions may impact clinical decisions in the course of managing infertility. Given that the functional integrities of FF and CCs are susceptible to concurrent pathological conditions, it is important to understand how pathophysiological factors influence natural fertility and the outcomes of pregnancy arising from the use of assisted reproduction technologies (ARTs). Accordingly, this review discusses the roles of CCs and FF in ensuring oocyte competence and present new insights on pathological conditions that may interfere with oocyte quality by altering the intrafollicular environment.
Assuntos
Células do Cúmulo , Líquido Folicular/fisiologia , Oócitos/fisiologia , Animais , Células do Cúmulo/citologia , Células do Cúmulo/fisiologia , Diabetes Mellitus/patologia , Endometriose/patologia , Feminino , Líquido Folicular/citologia , Humanos , Infertilidade Feminina/etiologia , Infertilidade Feminina/patologia , Obesidade/complicações , Obesidade/patologia , Oócitos/citologia , Infecção Pélvica/complicações , Infecção Pélvica/patologia , Síndrome do Ovário Policístico , GravidezRESUMO
This study aims to investigate the effect 5-azacytidine (5-Aza) during induction of pluripotency in bovine fibroblasts and to evaluate the effects of BMP2, BMP4 or follicular fluid in the differentiation of reprogrammed fibroblasts in primordial germ cells and oocytes. It also analysis the mRNA levels for OCT4, NANOG, REX, SOX2, VASA, DAZL, cKIT, SCP3, ZPA and GDF9 after culturing 5-Aza treated fibroblasts in the different tested medium. Dermal fibroblasts were cultured and exposed to 0.5, 1.0 or 2.0 µM of 5-Aza for 18 h, 36 h or 72 h. Then, the cells were cultured in DMEM/F12 supplemented with 10 ng/ml BMP2, 10 ng/ml BMP4 or 5% follicular fluid. After culture, morphological characteristics, viability and gene expression were evaluated by qPCR. Treatment of skin fibroblasts with 2.0 µM 5-Aza for 72 h significantly increased expression of mRNAs for SOX2, OCT4, NANOG and REX. The culture in medium supplemented with BMP2, BMP4 or follicular fluid for 7 or 14 days induced formation of oocyte-like cells, as well as the expression of markers for germ cells and oocyte. In conclusion, treatment of bovine skin-derived fibroblasts with 2.0 µM 5-Aza for 72 h induces the expression of pluripotency factors. Culturing these cells in differentiation medium supplemented with BMP2, BMP4 or follicular fluid induces morphological changes and promotes expression of markers for germ cells, meiosis and oocyte.
Assuntos
Azacitidina/farmacologia , Diferenciação Celular/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/fisiologia , Marcadores Genéticos/genética , Animais , Proteína Morfogenética Óssea 2/farmacologia , Proteína Morfogenética Óssea 4/farmacologia , Bovinos , Diferenciação Celular/genética , Meios de Cultura/química , Meios de Cultura/farmacologia , RNA Helicases DEAD-box/genética , Feminino , Fibroblastos/efeitos dos fármacos , Líquido Folicular/fisiologia , Células-Tronco Pluripotentes/fisiologia , Pele/citologia , Pele/embriologia , Glicoproteínas da Zona Pelúcida/genéticaRESUMO
The aim of this work was to determine the enzymatic activity of phosphofructokinase (PFK), malate dehydrogenase (MDH) and isocitrate dehydrogenase (IDH) in boar spermatozoa and study their participation in bicarbonate-induced capacitation and follicular fluid-induced acrosome reaction. Enzymatic activity of these enzymes was determined spectrophotometrically in extracts of boar spermatozoa. Sperm suspensions were incubated in the presence of bicarbonate (40 mM), a well-known capacitation inducer, or follicular fluid (30%), as an acrosome reaction inducer, and different concentrations of oxoglutarate, oxalomalate and hydroxymalonate, inhibitors of PFK, IDH and MDH, respectively. Capacitation percentages were determined by the fluorescence technique of chlortetracycline (CTC), and true acrosome reaction was determined by trypan blue and differential-interferential contrast, optical microscopy. The activity of PFK in boar spermatozoa enzymatic extracts was 1.70 ± 0.19 U/1010 spermatozoa, the activity of NAD- and NADP-dependent IDH was 0.111 ± 0.005 U/1010 and 2.22 ± 0.14 U/1010 spermatozoa, respectively, and the activity of MDH was 4.24 ± 0.38 U/1010 spermatozoa. The addition of the specific inhibitors of these enzymes prevented sperm capacitation and decreased sperm motility during capacitation and inhibited the acrosome reaction (AR), without affecting the sperm motility during this process. Our results demonstrate the participation of PFK, IDH and MDH in bicarbonate-induced capacitation and follicular fluid-induced acrosome reaction in boar spermatozoa, contributing to elucidate the mechanisms that produce energy necessary for these processes in porcine spermatozoa.
Assuntos
Reação Acrossômica/efeitos dos fármacos , Isocitrato Desidrogenase/metabolismo , Malato Desidrogenase/metabolismo , Fosfofrutoquinases/metabolismo , Capacitação Espermática/efeitos dos fármacos , Espermatozoides/enzimologia , Animais , Bicarbonatos/farmacologia , Feminino , Líquido Folicular/fisiologia , Isocitrato Desidrogenase/antagonistas & inibidores , Malato Desidrogenase/antagonistas & inibidores , Masculino , Fosfofrutoquinases/antagonistas & inibidores , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Sus scrofa , Tartronatos/farmacologiaRESUMO
Fertility - the ability to produce offspring - is considered a prerequisite for the development and perpetuation of species. Several factors may positively or negatively affect one's reproductive capabilities, such as regular exercises and maintaining a healthy bodyweight, versus aging, obesity, and stress. Follicular fluid (FF) is a liquid composed primarily of hormones, enzymes, anticoagulants, electrolytes, reactive oxygen species and antioxidants, which fills the follicular antrum and acts as an important mediator in the communication between cells in the antral follicle while bathing and carrying nutrients to the oocyte. Thus, human FF is a key element to the success of natural fertilization present in every stage of the conception process, from the communication between gametes to the development of fully viable embryos, and a vital component in the occurrence of spontaneous pregnancies. This literature review aimed to describe the possible effects of human follicular fluid on the natural fertilization process and to assess its role in follicular growth, oocyte quality, sperm capacitation, fertilization, and early embryonic development.
Assuntos
Fertilização/fisiologia , Líquido Folicular , Feminino , Líquido Folicular/química , Líquido Folicular/metabolismo , Líquido Folicular/fisiologia , Humanos , Masculino , Gravidez , Capacitação Espermática/fisiologiaRESUMO
The objective of this study was to determine the effects of insulin-like growth factor-I (IGF-I) (0, 60, 120, 180, and 240 ng/mL) and follicular fluid (FF) derived from 2 to 5 and 6 to 10 mm diameter follicles (SpFFs and LpFFs, respectively) added during in vitro maturation (IVM) of porcine oocytes on nuclear maturation and IVF. Cumulus-oocyte complexes (COCs) were matured in NCSU-37 medium supplemented with SpFFs or LpFFs and various IGF-I concentrations. The COCs were cultured for 44 hours, and then fertilized in vitro. Maturation and IVF results were recorded 18 hours after insemination. The IVM (%) was higher (P < 0.05) in the COCs matured in LpFFs than with SpFFs when 0 (90.0 ± 6.9 vs. 76.3 ± 10.7) or 60 ng/mL IGF-I (92.0 ± 8.1 vs. 81.8 ± 10.2) was added. In SpFFs media, there was a quadratic relationship (P < 0.01) between IGF-I concentration and IVM (peak results at IGF-I = 129 ng/mL). However, when the COCs were matured with LpFFs, there was a decreasing linear effect between IGF-I concentration and IVM. At all concentrations of IGF-I, the percentage of degenerated oocytes was higher in COCs matured in SpFFs than in LpFFs. Penetration (%) did not differ (P > 0.05) between COCs matured with SpFFs or LpFFs when 60 (66.8 ± 9.4 vs. 72.7 ± 11.3) or 180 ng/mL of IGF-I (75.7 ± 10.4 vs. 73.8 ± 13.2) were used. Monospermy (%) was similar between SpFFs and LpFFs only with addition of 120 ng/mL IGF-I. The IVF performance (%) did not differ between COCs matured with SpFFs or LpFFs when IGF-I concentrations of 120 (28.5 ± 8.8 vs. 38.5 ± 8.3) and 180 ng/mL (24.3 ± 10.2 vs. 30.12 ± 8.2) were used. There was no effect of IGF-I concentration or of FF type on the number of penetrated sperm per oocyte and on male pronuclear formation. For COCs matured with SpFFs, there was a quadratic relationship between IGF-I concentration and penetration, monospermy, and IVF performance (peak results at IGF-I = 179, 122, and 135 ng/mL, respectively). Thus, on the basis of the observed quadratic relationships, we inferred that when using SpFFs, the addition of IGF-I (122-179 ng/mL) to the IVM medium produced results similar to those obtained with LpFFs without adding IGF-I. In conclusion, the addition of IGF-I to the IVM medium supplemented with SpFFs increased maturation and improved IVF results. Alternatively, IGF-I had no effect on IVM or IVF when used with LpFFs.
Assuntos
Fertilização in vitro/veterinária , Líquido Folicular/fisiologia , Técnicas de Maturação in Vitro de Oócitos/veterinária , Fator de Crescimento Insulin-Like I/fisiologia , Folículo Ovariano/citologia , Folículo Ovariano/fisiologia , Suínos , Animais , Tamanho Celular , Células Cultivadas , Feminino , Líquido Folicular/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/farmacologia , Masculino , Oócitos/efeitos dos fármacos , Oócitos/fisiologia , Oogênese/efeitos dos fármacos , Suínos/embriologia , Suínos/fisiologiaRESUMO
OBJECTIVE: A pill containing ulipristal acetate (UPA) is used for emergency contraception (EC). Considering that, following its intake, spermatozoa may be exposed to UPA in the female genital tract we intended to evaluate sperm functions after incubation with this compound. METHODS: Motile spermatozoa were selected by swim-up and were incubated under capacitating conditions with UPA (at concentrations of 1, 10, 100, 1,000, and 10,000 ng/ml) or control medium. The main outcome measures were sperm vitality, sperm protein tyrosine phosphorylation (TyrP), spontaneous acrosomal reaction (AR), and human follicular fluid (hFF)-induced AR. RESULTS: Sperm vitality and TyrP pattern were similar between spermatozoa exposed to UPA or control. In addition, spontaneous AR ranged from 14.0 ±1.5% to 18.0 ±1.9% after exposure to UPA or control medium without significant differences, and UPA did not prevent hFF-induced AR. CONCLUSIONS: Incubation of sperm with UPA at concentrations around the expected plasma levels after ingestion of this EC pill (Ë100-200 ng/ml) did not modify the signal transduction of TyrP involved in sperm capacitation. Moreover, UPA showed no agonist effect on progesterone receptors because it did not induce AR. Considering that progesterone in hFF is essential for AR induction, and UPA did not prevent the hFF-induced AR, an antagonist action of UPA on the AR is unlikely.
Assuntos
Reação Acrossômica/efeitos dos fármacos , Anticoncepcionais Sintéticos Pós-Coito/farmacologia , Norpregnadienos/farmacologia , Espermatozoides/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Líquido Folicular/fisiologia , Humanos , Técnicas In Vitro , Masculino , Fosforilação/efeitos dos fármacos , Capacitação Espermática/efeitos dos fármacos , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologiaRESUMO
The aim of this study was to evaluate the effect of follicular fluid collected from bovine dominant follicles (bFF) on the in vitro development of goat preantral follicles and determine the best time to add this supplement to the culture medium. The preantral follicles were isolated and randomly distributed into four treatments in absence (control) or presence of 10% of bFF added on Days 0 (FF0-18), 6 (FF6-18) or 12 (FF12-18) of culture onwards. After 18 days, follicular development was assessed based on follicular survival, antral cavity formation, increased follicular diameter as well as fully grown oocyte (>110 µm) viability and meiosis resumption. The oocytes from the cultured follicles were in vitro-matured and processed for fluorescence or ultrastructural analysis. The results showed that on Day 18 the treatment FF0-18 had a significantly higher (P<0.05) survival than control and FF12-18, but not FF6-18. The addition of bFF at the beginning of culture (FF0-18 and FF6-18) promoted a high percentage of follicular growth, meiosis resumption and early antrum formation. Moreover, this study described for the first time the ultrastructural analysis of caprine oocytes grown in vitro. This evaluation revealed that in the presence of bFF on (FF0-18) the in vitro-grown oocytes presented normal organelle distribution and well-defined, intact plasma and nuclear membranes. In conclusion, bFF originating from dominant follicles maintain the survival and promote the in vitro growth of goat preantral follicles when added at the beginning of culture.
Assuntos
Meios de Cultivo Condicionados/farmacologia , Líquido Folicular/fisiologia , Cabras/fisiologia , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/fisiologia , Animais , Bovinos , Crescimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Oócitos/citologia , Oócitos/efeitos dos fármacos , Oócitos/crescimento & desenvolvimento , Oócitos/ultraestrutura , Oogênese/efeitos dos fármacos , Oogênese/fisiologia , Folículo Ovariano/citologia , Folículo Ovariano/ultraestrutura , Distribuição AleatóriaRESUMO
The aim of this study was to elucidate the mechanism involved in the acrosome reaction (AR) induced by follicular fluid (FF) in spermatozoa previously exposed to peritoneal fluid (PF). The influence of progesterone was also investigated. Semen samples were from 18 normozoospermic donors. PF samples were from 13 women with unexplained infertility and from a woman treated with synthetic progestagen. FF samples were collected from six women undergoing IVF/embryo transfer and pooled. Motile spermatozoa were capacitated overnight and a kinetic and inhibition study on the FF-induced AR was performed. Spermatozoa pretreated with PF were challenged with either FF or progesterone. The ability of progesterone- and progestagen-supplemented PF to induce AR was analysed. Enzyme-digested PF was also tested. Pre-incubation with PF for 60 min completely prevented the FF-induced AR; spermatozoa treated with PF were unable to respond to FF or progesterone and this effect was not reversible. Progesterone- and progestagen-supplemented PF stimulated the AR relative to controls. Enzyme-digested PF did not have an inhibitory capacity. These data strongly suggest that there are one or more inhibitory proteins in PF that interact with spermatozoa so as to prevent access of progesterone to its receptor and thus inhibit the occurrence of the AR. The oviduct, or Fallopian tube, provides a place for spermatozoa and egg transport and storage, fertilization and early embryo development. If ovulation has not occurred, spermatozoa may reside in the oviduct for several hours or even a few days, awaiting oocyte arrival. It is assumed that fluids present in the female genital tract may have a role in synchronizing the timing required to guarantee the success of fertilization. We previously observed that the peritoneal fluid that bathes the peritoneal cavity is a suitable medium for sperm survival and we also reported that this fluid could stabilize spermatozoa. In this study we show further evidence that the exposure to peritoneal fluid modifies the response of spermatozoa to oocyte signals.