Extract of Cimicifuga racemosa (L.) Nutt protects ovarian follicle reserve of mice against in vitro deleterious effects of dexamethasone.

The present study aims to investigate if Cimicifuga racemosa (L.) Nutt extract (CIMI) reduces deleterious effects of dexamethasone (DEXA) in ovaries cultured in vitro. Mouse ovaries were collected and cultured in DMEM+ only or supplemented with 5 ng/mL of CIMI, or 4 ng/mL DEXA, or both CIMI and DEXA. The ovaries were cultured at 37.5°C in 5% CO2 for 6 days. Ovarian morphology, follicular ultrastructure, and the levels of mRNA for Bax, Bcl-2, and Caspase-3 were evaluated. The results showed that DEXA reduced the percentage of morphologically normal follicles, while CIMI prevented the deleterious effects caused by DEXA. In addition, DEXA negatively affected the stromal cellular density, while CIMI prevented these adverse effects. Ovaries cultured with DEXA and CIMI showed similar levels of mRNA for Bax, Bcl-2, and Caspase-3 compared to those cultured in control medium, while ovaries cultured with DEXA had increased expression of the above genes. Additionally, the ultrastructure of the ovaries cultured with CIMI was well preserved. Thus, the extract of CIMI was able to prevent the deleterious effects caused by DEXA on cultured mouse ovaries.

Effects of antifreeze protein from Lolium perenne L. (LpAFP) in the vitrification of in vitro-produced bovine embryos.

In the present study, the cryoprotective effects of Lolium perenne antifreeze protein (LpAFP) on the vitrification of bovine embryos were evaluated. In vitro-produced blastocysts were divided into two groups: the control group (CG) without the addition of LpAFP and the treatment group (TG) with the addition of 500 ng/ml of LpAFP in the equilibrium and vitrification solution. Vitrification was carried out by transferring the blastocysts to the equilibrium solution [7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (DMSO)] for 2 min and then to the vitrification solution (15% EG, 15% DMSO and 0.5M sucrose). The blastocysts were deposited on a cryotop device and submerged in liquid nitrogen. Warming was carried out in three steps in solutions with different sucrose concentrations (1.0, 0.5, and 0.0 M, respectively). Embryos were evaluated for re-expansion/hatching, the total cell count, and ultrastructural analysis. There was no significant difference in the re-expansion rate 24 h after warming; however, there was variation (P < 0.05) in the hatching rate in the TG and the total number of cells 24 h after warming was higher in the TG (114.87 ± 7.24) when compared with the CG (91.81 ± 4.94). The ultrastructural analysis showed changes in organelles related to the vitrification process but, in the TG, there was less damage to mitochondria and rough endoplasmic reticulum compared with the CG. In conclusion, the addition of 500 ng/ml of LpAFP during the vitrification of in vitro-produced bovine embryos improved the hatching rate and total cell number of blastocysts after warming and mitigated intracellular damage.

Extract of Cimicifuga racemosa (L.) Nutt protects ovarian follicle reserve of mice against in vitro deleterious effects of dexamethasone

The present study aims to investigate if Cimicifuga racemosa (L.) Nutt extract (CIMI) reduces deleterious effects of dexamethasone (DEXA) in ovaries cultured in vitro. Mouse ovaries were collected and cultured in DMEM+ only or supplemented with 5 ng/mL of CIMI, or 4 ng/mL DEXA, or both CIMI and DEXA. The ovaries were cultured at 37.5°C in 5% CO2 for 6 days. Ovarian morphology, follicular ultrastructure, and the levels of mRNA for Bax, Bcl-2, and Caspase-3 were evaluated. The results showed that DEXA reduced the percentage of morphologically normal follicles, while CIMI prevented the deleterious effects caused by DEXA. In addition, DEXA negatively affected the stromal cellular density, while CIMI prevented these adverse effects. Ovaries cultured with DEXA and CIMI showed similar levels of mRNA for Bax, Bcl-2, and Caspase-3 compared to those cultured in control medium, while ovaries cultured with DEXA had increased expression of the above genes. Additionally, the ultrastructure of the ovaries cultured with CIMI was well preserved. Thus, the extract of CIMI was able to prevent the deleterious effects caused by DEXA on cultured mouse ovaries.

Isolates of Bacillus thuringiensis from Maranhão biomes with potential insecticidal action against Aedes aegypti larvae (Diptera, Culicidae) / Isolados de Bacillus thuringiensis de biomas maranhenses com potencial ação inseticida contra larvas de Aedes aegypti (Diptera, Culicidae)

Abstract Entomopathogenic agents are viable and effective options due to their selective action against insects but benign effects on humans and the environment. The most promising entomopathogens include subspecies of Bacillus thuringiensis (Bt), which are widely used for the biological control of insects, including mosquito vectors of human pathogens. The efficacy of B. thuringiensis toxicity has led to the search for new potentially toxic isolates in different regions of the world. Therefore, soil samples from the Amazon, Cerrado and Caatinga biomes of the state of Maranhão were evaluated for their potential larvicidal action against Aedes aegypti. The isolates with high toxicity to mosquito larvae, as detected by bioassays, were subjected to histological evaluation under a light microscope to identify the genes potentially responsible for the toxicity. Additionally, the toxic effects of these isolates on the intestinal epithelium were assessed. In the new B. thuringiensis isolates toxic to A. aegypti larvae, cry and cyt genes were amplified at different frequencies, with cry4, cyt1, cry32, cry10 and cry11 being the most frequent (33-55%) among those investigated. These genes encode specific proteins toxic to dipterans and may explain the severe morphological changes in the intestine of A. aegypti larvae caused by the toxins of the isolates.

Resumo Os agentes entomopatógenos são alternativas viáveis e eficazes, devido à sua ação seletiva para insetos sendo inofensivos ao homem e ao meio ambiente. Dentre os entomopatógenos mais promissores, destacam-se as subespécies de Bacillus thuringiensis (Bt) amplamente utilizadas no controle biológico de insetos incluindo espécies de mosquitos vetores de agentes patogênicos ao homem. A eficiência da toxicidade de Bt incentiva a prospecção de novos isolados em diversas regiões do mundo. Desta forma, em busca de novos isolados de B. thuringiensis potencialmente tóxicos, amostras de solo provenientes dos biomas Amazônia, Cerrado e Caatinga do estado do Maranhão foram avaliadas em relação ao seu potencial larvicida para Aedes aegypti. Os isolados que provocaram elevada toxicidade para larvas do mosquito, detectada por bioensaios, foram avaliados em relação aos potenciais genes responsáveis pela atividade tóxica, além da avaliação de efeitos tóxicos no epitélio intestinal através de análises histológicas em microscopia de luz. Os novos isolados de Bt tóxicos para larva de A. aegypti amplificaram frequências diferentes de genes cry e cyt sendo os mais frequentes (55-33%) os cry4, cyt1, cry32, cry10 e cry11 dentre os investigados. Esses genes codificam para proteínas tóxicas específicas para ordem Diptera, e podem explicar as severas alterações morfológicas provocadas pelas toxinas dos isolados observadas no intestino das larvas de A. aegypti.

Isolates of Bacillus thuringiensis from Maranhão biomes with potential insecticidal action against Aedes aegypti larvae (Diptera, Culicidae).

Entomopathogenic agents are viable and effective options due to their selective action against insects but benign effects on humans and the environment. The most promising entomopathogens include subspecies of Bacillus thuringiensis (Bt), which are widely used for the biological control of insects, including mosquito vectors of human pathogens. The efficacy of B. thuringiensis toxicity has led to the search for new potentially toxic isolates in different regions of the world. Therefore, soil samples from the Amazon, Cerrado and Caatinga biomes of the state of Maranhão were evaluated for their potential larvicidal action against Aedes aegypti. The isolates with high toxicity to mosquito larvae, as detected by bioassays, were subjected to histological evaluation under a light microscope to identify the genes potentially responsible for the toxicity. Additionally, the toxic effects of these isolates on the intestinal epithelium were assessed. In the new B. thuringiensis isolates toxic to A. aegypti larvae, cry and cyt genes were amplified at different frequencies, with cry4, cyt1, cry32, cry10 and cry11 being the most frequent (33-55%) among those investigated. These genes encode specific proteins toxic to dipterans and may explain the severe morphological changes in the intestine of A. aegypti larvae caused by the toxins of the isolates.

Effects of dexamethasone on growth, viability and ultrastructure of bovine secondary follicles cultured in vitro.

This study aimed to evaluate the effects of dexamethasone on development, viability, antrum formation and ultrastructural integrity of bovine secondary follicles cultured in vitro for 18 days. Bovine ovaries were obtained from slaughterhouses and secondary follicles of ~150-200 µm diameter were isolated and cultured in the laboratory in TCM-199+ alone or supplemented with different concentrations of dexamethasone (1, 10, 100 and 1000 ng/ml). Follicle viability was evaluated after the culture period, using calcein-AM (viable) and ethidium homodimer (nonviable). Follicle diameters and antrum formation were evaluated at days 0, 6, 12 and 18. Before or after in vitro culture, follicles were fixed for histological and ultrastructural analysis. Follicle diameters were evaluated using analysis of variance and Kruskal-Wallis test, while chi-squared test was used to evaluate the percentage of viable follicles and antrum formation (P < 0.05). Follicles cultured for 6 days with all treatments increased their diameters significantly, but there was no significant difference between treatments at the end of the culture period. In vitro cultured follicles showed antral cavity formation at the end of the culture period, but no influence of dexamethasone was seen. Ultrastructural analysis showed that follicles cultured with dexamethasone (1, 10, 100 and 1000 ng/ml) had well preserved granulosa cells. However, oocytes from follicles cultured with 10, 100 or 1000 ng/ml dexamethasone showed signs of degeneration. It can be concluded that follicles cultured in vitro in the presence of dexamethasone demonstrated continuous in vitro growth, but oocytes from follicles cultured with 10, 100 or 1000 ng/ml dexamethasone had poor ultrastructure.

Effects of epidermal growth factor and progesterone on development, ultrastructure and gene expression of bovine secondary follicles cultured in vitro.

The aims of this study were to investigate the effects of epidermal growth factor (EGF) and progesterone on the development, viability and the gene expression of bovine secondary follicle culture in vitro for 18 days. Secondary follicles (∼0.2 mm) were isolated from ovarian cortex and individually cultured at 38.5 °C, with 5% CO2 in air, for 18 days, in TCM-199+ (n = 63) alone (control medium) or supplemented with 10 ng/mL progesterone (n = 64), 10 ng/mL EGF (n = 61) or both EGF and progesterone (n = 66). The effects of these treatments on growth, antrum formation, viability, ultrastructure and mRNA levels for GDF-9, c-MOS, H1foo and cyclin B1 were evaluated, significantly different (p < 0.05). The results showed that there was a progressive increase in follicular diameter in all treatments, but only follicles cultured in medium supplemented with EGF had increased significantly in diameter when compared to follicles cultured in the control medium at the end of the culture period, significantly different (p < 0.05). A positive interaction between EGF and progesterone was not observed. In addition, the presence of EGF, progesterone or both in culture medium did not influence the rate of follicle survival and antrum formation. However, the presence of only progesterone in cultured medium increased the expression of mRNAs for GDF9 and cyclin B1 in oocytes. EGF also significantly increased the levels of mRNAs for cMOS and GDF9 when compared to follicles cultured in control medium. Ultrastructural analyzes showed that cultured follicles in all treatments maintained the integrity of granulosa cells. In conclusion, the EGF promotes the development of secondary follicles cultured in vitro for 18 days and increases the expression of cMOS and GDF9, while progesterone alone or in association with EGF have not a positive effect on follicular growth. However, progesterone increases the expression of GDF9 and cyclin B1 in oocytes.

Expression of TNF-α system members in bovine ovarian follicles and the effects of TNF-α or dexamethasone on preantral follicle survival, development and ultrastructure in vitro.

This study was conducted to detect the protein expression of TNF-α system members (TNF-α/TNFR1/TNFR2) in bovine ovarian follicles and to evaluate the effects of TNF-α or dexamethasone on the survival and growth of primordial follicles in vitro, as well as on gene expression in cultured ovarian tissue. It was hypothesized that TNF-α induces follicular atresia in ovarian tissues cultured in vitro, and that dexamethasone suppresses the production of endogenous TNF-α, which can improve follicle viability in vitro. Ovarian fragments were cultured for 6days in α-MEM+ supplemented with TNF-α (0, 1, 10, 100 or 200ng/ml) or dexamethasone (0, 1, 10, 100 or 200ng/ml). After culture, the expression of mRNAs for BCL-2, BAX, P53, TNF-α, and CASP3 and CASP6 were evaluated. Immunohistochemical results showed that the TNF-α system members, were detected in bovine preantral and antral follicles. After 6days, the TNF-α (10ng/ml) treatment reduced the percentage of normal preantral follicles and increased the number of TUNEL-positive cells in cultured tissue. Dexamethasone (10ng/ml) during 6days of culture did maintain the percentage of normal follicles and the ultrastructure of follicles, while the presence of TNF-α or dexamethasone did not influence primordial follicle activation. However, TNF-α or dexamethasone had no effect on the levels of mRNA for P53, BCL-2, BAX and CASP6, in cultured tissues, but the presence of dexamethasone reduced the levels of CASP3 compared to ovarian slices cultured in control medium (α-MEM+). In conclusion, proteins of the TNF-α system are expressed at different bovine follicle stages. The addition of TNF-α in culture reduces follicle survival and increases the number of apoptotic cells in ovarian tissue, while the presence of dexamethasone maintains follicle ultrastructure in cultured tissue.

mRNA expression profile of the TNF-α system in LH-induced bovine preovulatory follicles and effects of TNF-α on gene expression, ultrastructure and expansion of cumulus-oocyte complexes cultured in vitro.

This study evaluated (1) the effects of in vivo GnRH treatment on mRNA expression of TNF-α system (TNF-α, TNFR1 and TNFR2) in granulosa cells of bovine preovulatory follicles, (2) the in vitro influence of gonadotropins on mRNA expression of TNF-α system in cultured cumulus cells, (3) the protein expression of the TNF-α system in late antral follicles and, (4) the influence of TNF-α on cumulus cells expansion, ultrastructure and on expression of HAS2, CASP3 and CASP6 in follicular cells cultured for 24 h. An increased expression of TNF-α and TNFR1 was observed after 3, 6 and 12 h of GnRH treatment when compared to 0 and 24h. Higher TNFR2 mRNA levels were observed 3, 6 and 12 h after GnRH, when compared to 0 and 24 h. Proteins of TNF-α system were also expressed in late antral follicles. In vitro, TNF-α did not affect cumulus cells expansion, but reduced the HAS2, CASP3 and CASP6 mRNA levels in cumulus cells after 12 h. After 24 h of culture, TNF-α increased the mRNA levels for CASP6 in mural granulosa cells, while the TNF-α, TNFR1 and TNFR2 mRNA levels were increased in cumulus-oocyte complexes (COCs) cultured for 12 h with gonadotropins, but not after 24 h. Ultrastructural analysis confirmed the integrity of COCs cultured in presence of TNF-α. In conclusion, TNF-α system members are present in bovine antral follicles and expression of TNF-α is influenced by gonadotropins in vivo and in vitro. In vitro, TNF-α maintained cumulus cells ultrastructure during COC culture.

Isolates of Bacillus thuringiensis from Maranhão biomes with potential insecticidal action against Aedes aegypti larvae (Diptera, Culicidae)

Abstract Entomopathogenic agents are viable and effective options due to their selective action against insects but benign effects on humans and the environment. The most promising entomopathogens include subspecies of Bacillus thuringiensis (Bt), which are widely used for the biological control of insects, including mosquito vectors of human pathogens. The efficacy of B. thuringiensis toxicity has led to the search for new potentially toxic isolates in different regions of the world. Therefore, soil samples from the Amazon, Cerrado and Caatinga biomes of the state of Maranhão were evaluated for their potential larvicidal action against Aedes aegypti. The isolates with high toxicity to mosquito larvae, as detected by bioassays, were subjected to histological evaluation under a light microscope to identify the genes potentially responsible for the toxicity. Additionally, the toxic effects of these isolates on the intestinal epithelium were assessed. In the new B. thuringiensis isolates toxic to A. aegypti larvae, cry and cyt genes were amplified at different frequencies, with cry4, cyt1, cry32, cry10 and cry11 being the most frequent (33-55%) among those investigated. These genes encode specific proteins toxic to dipterans and may explain the severe morphological changes in the intestine of A. aegypti larvae caused by the toxins of the isolates.

Resumo Os agentes entomopatógenos são alternativas viáveis e eficazes, devido à sua ação seletiva para insetos sendo inofensivos ao homem e ao meio ambiente. Dentre os entomopatógenos mais promissores, destacam-se as subespécies de Bacillus thuringiensis (Bt) amplamente utilizadas no controle biológico de insetos incluindo espécies de mosquitos vetores de agentes patogênicos ao homem. A eficiência da toxicidade de Bt incentiva a prospecção de novos isolados em diversas regiões do mundo. Desta forma, em busca de novos isolados de B. thuringiensis potencialmente tóxicos, amostras de solo provenientes dos biomas Amazônia, Cerrado e Caatinga do estado do Maranhão foram avaliadas em relação ao seu potencial larvicida para Aedes aegypti. Os isolados que provocaram elevada toxicidade para larvas do mosquito, detectada por bioensaios, foram avaliados em relação aos potenciais genes responsáveis pela atividade tóxica, além da avaliação de efeitos tóxicos no epitélio intestinal através de análises histológicas em microscopia de luz. Os novos isolados de Bt tóxicos para larva de A. aegypti amplificaram frequências diferentes de genes cry e cyt sendo os mais frequentes (55-33%) os cry4, cyt1, cry32, cry10 e cry11 dentre os investigados. Esses genes codificam para proteínas tóxicas específicas para ordem Diptera, e podem explicar as severas alterações morfológicas provocadas pelas toxinas dos isolados observadas no intestino das larvas de A. aegypti.

Expression of angiotensin II receptors in the caprine ovary and improvement of follicular viability in vitro.

This study aimed to evaluate mRNA levels of angiotensin II (ANG II) receptors (AGTR1 and AGTR2) in caprine follicles and to investigate the influence of ANG II on the viability and in vitro growth of preantral follicles. Real-time polymerase chain reaction (PCR) was used to quantify AGTR1 and AGTR2 mRNA levels in the different follicular stages. For culture, caprine ovaries were collected, cut into 13 fragments and then either directly fixed for histological and ultrastructural analysis (fresh control) or placed in culture for 1 or 7 days in α-minumum essential medium plus (α-MEM+) with 0, 1, 5, 10, 50 or 100 ng/ml ANG II. Then, the fragments were destined to morphological, viability and ultrastructural analysis. The results showed that primordial follicles had higher levels of AGTR1 and AGTR2 mRNA than secondary follicles. Granulosa/theca cells from antral follicles had higher levels of AGTR1 mRNA than their respective cumulus-oocyte complex (COCs). After 7 days of culture, ANG II (10 or 50 ng/ml) maintained the percentages of normal follicles compared with α-MEM+. Fluorescence and ultrastructural microscopy confirmed follicular integrity in ANG II (10 ng/ml). In conclusion, a high expression of AGTR1 and AGTR2 is observed in primordial follicles. Granulosa/theca cells from antral follicles had higher levels of AGTR1 mRNA. Finally, 10 ng/ml ANG II maintained the viability of caprine preantral follicles after in vitro culture.

Sildenafil (Viagra®) blocks inflammatory injury in LPS-induced mouse abortion: A potential prophylactic treatment against acute pregnancy loss?

INTRODUCTION: Recurrent pregnancy losses (RPL) are common women's health issues. Inflammatory and thrombotic events have been associated with RPL including excessive production of cytokines, in particular TNF-α. However, mechanisms behind gestational losses are not yet fully understood. Sildenafil inhibits phosphodiesterase Type-5 (PDE5). This drug increases intracellular cyclic guanosine monophosphate, having vasodilatory and, more recently described, anti-inflammatory properties. PDE5 is present in murine and human uterus and placenta. Sildenafil is already used clinically for treatment of human fetal growth restriction (FGR). Our objective was to determine if Sildenafil alone or in combination with Heparin had protective effects in pregnant Swiss albino challenged to abort by lipopolysaccharide (LPS). METHODS: Treatments (Sildenafil (50 mg/kg/day), Heparin (500 IU/Kg/day) or Sildenafil + Heparin at the same doses) were initiated the morning of copulation plug detection (gestational day (gd0)). On the 15th day of pregnancy, an intra-peritoneal injection of LPS (100 µg/kg) was administered. Untreated, pregnant mice challenged by LPS served as controls. RESULTS: Assessments at 48 h after LPS revealed that Sildenafil + Heparin prevented fetal loss. Early assessments at 2 h after LPS indicated that the pretreatments prevented induction of inflammatory cytokine production (TNF-α, IL-1ß/NF-κß) and preserved placental histopathology. DISCUSSION: Combined Sildenafil + Heparin therapy was superior to either treatment alone in most analyses. The known safety of Sildenafil and Heparin in human pregnancy suggests that usage of these combined agents may be of value for treatment of patients with impending pregnancy loss or prophylactically in women with a history of recurrent miscarriages.

Effect of sequential medium with fibroblast growth factor-10 and follicle stimulating hormone on in vitro development of goat preantral follicles.

A sequential medium with fibroblast growth factor-10 (FGF-10) and follicle stimulating hormone (FSH) was evaluated on the survival, ultrastructure, activation and growth rate of caprine preantral follicles submitted to long-term culture, aiming to establish an ideal in vitro culture system. Ovarian fragments were cultured for 16 days in α-MEM(+) alone or supplemented with FGF-10 and/or FSH added sequentially on different days of culture. Ovarian fragments were cultured during the first (days 0-8) and second (days 8-16) halves of the culture period, generating 10 treatments: α-MEM(+)/α-MEM(+) (cultured control), FSH/FSH, FSH/FGF-10, FSH/FSH+FGF-10, FGF-10/FGF-10, FGF-10/FSH, FGF-10/FSH+FGF-10, FSH+FGF-10/FSH+FGF-10, FSH+FGF-10/FSH and FSH+FGF-10/FGF-10. Follicle morphology, viability and ultrastructure were analyzed. The FSH/FGF-10 treatment showed a higher (P<0.05) percentage of normal follicles compared to all other treatments. In addition, follicles from the FSH/FGF-10 treatment maintained ultrastructural integrity after the culture period. After 16 days of culture, the FSH/FGF-10 and FSH/FSH treatments showed a higher percentage of activation compared to the cultured control (α-MEM(+)/α-MEM(+)). Moreover, the FSH/FGF-10 treatment promoted greater follicular and oocyte diameters compared to the fresh control. In conclusion, this study showed that a sequential medium with FSH followed by FGF-10 (FSH/FGF-10 and FSH/FSH) maintains follicular viability and ultrastructure and promotes transition from the primordial to primary stage (activation) and growth in goat preantral follicles cultured in vitro.

Ultrastructure evaluation of goat spermatozoa after freezing in a skim milk-based extender with Trolox supplementation.

The aim of this work was to evaluate the in vitro effect of adding Trolox in freezing extender for goat semen. Ejaculates from five bucks were evaluated, and when approved, the samples were pooled, diluted according to experimental groups [Trolox 0 (control), 30, 60 and 120 nmol ml(-1) ] and frozen in an automated system. Thawed samples (37 °C/30 s) were evaluated for plasma membrane (PMi) and acrosome integrity (Aci), mitochondrial membrane potential (MMP) and sperm kinematics by CASA system. Spermatozoa ultrastructure was evaluated in fresh and post-thawed semen. No significant difference (P > 0.05) was observed among control and Trolox groups in the analyses of PMi, Aci, MMP and CASA in goat spermatozoa after thawing. Samples of 60 and 120 nmol ml(-1) Trolox groups had a higher percentage of cells that had intact plasma membranes in spermatozoa head than in the other groups, although they did not differ (P > 0.05) before being frozen. A higher percentage (P < 0.05) of spermatozoa with intact mitochondria was observed in fresh semen, control and Trolox 60 nmol ml(-1) groups than in the other groups. Addition of Trolox to skim milk extender at 60 nmol ml(-1) ultrastructurally preserves the plasma membrane and mitochondrial sheath integrity in goat spermatozoa after cryopreservation.

Efeito da temperatura de descongelação na integridade de espermatozoides criopreservados de cães / The effect of the thawing temperature on the integrity of canine cryopreserved sperm

Avaliou-se a influência da temperatura de descongelação na integridade de espermatozoides criopreservados de cães. Foram utilizados reprodutores das raças Basset Hound (n=3) e Rottweiler (n=3), submetidos a colheitas de sêmen por manipulação peniana. As amostras de sêmen foram descongeladas a 37ºC/1min (G1) ou 70ºC/6s (G2) e avaliadas quanto à motilidade progressiva, vigor e integridade do acrossoma após 0, 30 e 60 minutos de incubação (37ºC), e ultraestrutura espermática imediatamente após a descongelação. Em todos os tempos de incubação, a motilidade progressiva dos espermatozoides descongelados a 70ºC por 6s (74,6%) foi mais alta (P<0,05) que a dos descongelados a 37ºC por 1min (64,6%). O vigor espermático não diferiu (P>0,05) entre os grupos, e o porcentual de gametas com acrossomas íntegros foi maior (P<0,05) nos espermatozoides do G1 do que no G2. Lesões ultraestruturais foram identificadas nos espermatozoides descongelados de ambos os grupos, em maior quantidade nos gametas do G2. Conclui-se que amostras congeladas de sêmen de cães devam ser descongeladas a 37ºC por 1min.

Aiming to evaluate the influence of the thawing temperature on the viability of canine cryopreserved sperm, Basset Hound (n=3) and Rottweiler (n=3) dogs were used, submitted to semen collected through manual manipulation. Semen samples were thawed at 37ºC during 1min (G1) or at 70ºC during 6s (G2), and evaluated for progressive motility, vigor and acrosome integrity, after 0, 30 e 60 minutes of incubation (37ºC), and sperm ultrastructure immediately after thawing. In all incubation times, the average of progressive motility was higher (P<0.05) in samples from G2 Group (74.6%) than from G1 (64.6%). Sperm vigor had no difference (P>0.05) between groups, and the percentage of gametes with intact acrosome was higher (P<0.05) on sperm cells from G1 than from G2. Ultrastructural changes were identified on dog sperm from both groups, and were observed in higher quantity in gametes from G2 Group. It can be concluded that samples of frozen dog sperm must be thawed at 37°C for 1min.

Phytohemagglutinin improves the development and ultrastructure of in vitro-cultured goat (Capra hircus) preantral follicles.

The objective this study was to determine the effect of phytohemagglutinin (PHA) on survival, growth and gene expression in caprine secondary follicles cultured in vitro. Secondary follicles (∼0.2 mm) were isolated from the cortex of caprine ovaries and cultured individually for 6 days in α-MEM+ supplemented with PHA (0, 1, 10, 50, 100, or 200 µg/mL). After 6 days of culture, follicle diameter and survival, antrum formation, ultrastructure and expression of mRNA for FSH receptors (FSH-R), proliferating cell nuclear antigen (PCNA), and neuronal nitric oxide synthase were determined. All treatments maintained follicular survival [α-MEM+ (94.59%); 1 µg/mL PHA (96.43%); 10 µg/mL PHA (84.85%); 50 µg/mL PHA (85.29%); 100 µg/mL PHA (88.57%), and 200 µg/mL PHA (87.50)], but the presence of 10 µg/mL PHA in the culture medium increased the antrum formation rate (21.21%) when compared with control (5.41%, P < 0.05) and ensured the maintenance of oocyte and granulosa cell ultrastructures after 6 days of culture. The expression of mRNA for FSH-R (2.7 ± 0.1) and PCNA (4.4 ± 0.2) was also significantly increased in follicles cultured with 10 µg/mL PHA in relation to those cultured in α-MEM+ (1.0 ± 0.1). In conclusion, supplementation of culture medium with 10 µg/mL PHA maintains the follicular viability and ultrastructure, and promotes the formation of antral cavity after 6 days of culture in vitro.

Accelerated growth of bovine preantral follicles in vitro after stimulation with both FSH and BMP-15 is accompanied by ultrastructural changes and increased atresia.

The objective of the present study was to determine the effects of bone morphogenetic protein (BMP)-15 and FSH on the growth, viability, and expression of mRNA for FSH (FSH-R) and BMP-15 (BMPR-IB and BMPR-II) receptors in cultured bovine secondary follicles. Secondary follicles were microdissected and cultured for 12 days in minimum essential medium-α alone or supplemented with BMP-15, sequential FSH, both BMP-15 and FSH, or BMP-15 from days 0 to 6, and FSH from days 7 to 12. Thereafter, the effect of these treatments on the follicular volume, viability, and antrum formation and the levels of mRNA for BMPR-IB, BMPR-II, and FSH-R were assessed. Compared with day 0, the follicles cultured with FSH or BMP-15, or both, had a significant and progressive increase in volume (P < 0.05). However, the follicles cultured for 12 days with both BMP-15 and FSH had the greatest volume and a greater rate of antrum formation than those in control medium, but results similar to those cultured with FSH (days 0 to 12) or BMP-15 (days 0 to 6) and FSH (days 7 to 12). Together with their accelerating effect on in vitro follicle growth, the combination of FSH and BMP-15 induced ultrastructural changes in the cultured follicles and increased atresia. However, adding either BMP-15 or FSH to the culture medium, not only promoted follicular growth and follicular antrum formation, but also maintained follicular viability during culture. Except for follicles cultured in minimal essential medium-α, the levels of mRNA for BMPR-IB were reduced, and the levels of mRNA for FSH-R were significantly greater in follicles cultured in medium supplemented with BMP-15. In conclusion, all in vitro follicle treatments supported growth of bovine preantral follicles; however, adding both BMP-15 and FSH to the culture medium (minimal essential medium-α) for 12 days provided the greatest stimulation. Furthermore, the viability and ultrastructural integrity of cultured follicles were only maintained when only BMP-15 or FSH was added to the culture medium.

Phytohemagglutinin improves the development and ultrastructure of in vitro-cultured goat (Capra hircus) preantral follicles

The objective this study was to determine the effect of phytohemagglutinin (PHA) on survival, growth and gene expression in caprine secondary follicles cultured in vitro. Secondary follicles (∼0.2 mm) were isolated from the cortex of caprine ovaries and cultured individually for 6 days in α-MEM+ supplemented with PHA (0, 1, 10, 50, 100, or 200 µg/mL). After 6 days of culture, follicle diameter and survival, antrum formation, ultrastructure and expression of mRNA for FSH receptors (FSH-R), proliferating cell nuclear antigen (PCNA), and neuronal nitric oxide synthase were determined. All treatments maintained follicular survival [α-MEM+ (94.59%); 1 µg/mL PHA (96.43%); 10 µg/mL PHA (84.85%); 50 µg/mL PHA (85.29%); 100 µg/mL PHA (88.57%), and 200 µg/mL PHA (87.50)], but the presence of 10 µg/mL PHA in the culture medium increased the antrum formation rate (21.21%) when compared with control (5.41%, P < 0.05) and ensured the maintenance of oocyte and granulosa cell ultrastructures after 6 days of culture. The expression of mRNA for FSH-R (2.7 ± 0.1) and PCNA (4.4 ± 0.2) was also significantly increased in follicles cultured with 10 µg/mL PHA in relation to those cultured in α-MEM+ (1.0 ± 0.1). In conclusion, supplementation of culture medium with 10 µg/mL PHA maintains the follicular viability and ultrastructure, and promotes the formation of antral cavity after 6 days of culture in vitro.

The effects of epidermal growth factor (EGF) on the in vitro development of isolated goat secondary follicles and the relative mRNA expression of EGF, EGF-R, FSH-R and P450 aromatase in cultured follicles.

The effects of varying concentrations of EGF were evaluated in terms of in vitro follicular development and the mRNA expression levels of EGF, EGF-R, FSH-R and P450 aromatase. After 6 days, the addition of 50 ng/mL of EGF to the culture medium increased the antrum formation rates in comparison to cultured control and after 18 days of culture produced oocytes with higher rates of meiosis resumption when compared to the other treatments (P<0.05). The daily follicular growth rates in presence of EGF (50 or 100) were increased in comparison to the cultured control (P<0.05). Treatment with EGF 50 stimulated the expression of EGF mRNA but reduced EGF-R mRNA expression and estradiol secretion as compared to the cultured control (P<0.05). After 18 days of culture, the mRNA levels for FSH-R and P450 aromatase were greater than those of the non-cultured controls (P<0.05). In conclusion, the effects of EGF treatment on the mRNA levels for EGF, EGF-R, FSH-R, and P450 aromatase varied according to the stage of follicle development.

The effects of insulin and follicle-simulating hormone (FSH) during in vitro development of ovarian goat preantral follicles and the relative mRNA expression for insulin and FSH receptors and cytochrome P450 aromatase in cultured follicles.

The actions of different concentrations of insulin alone or in combination with follicle-stimulating hormone (FSH) were evaluated by in vitro follicular development and mRNA expression of cytochrome P450 aromatase (CYP19A1) and as receptors for insulin (INSR) and FSH (FSHR) from isolated, cultured goat preantral follicles. Goat preantral follicles were microdissected and cultured for 18 days in the absence or presence of insulin (5 and 10 ng/ml or 10 µg/ml) alone or in combination with FSH. After 18 days, the addition of the maximum concentration of insulin to the culture medium reduced follicular survival and antrum formation rates significantly compared to the other treatments. However, when FSH was added to the culture medium, no differences between these two parameters were observed. Preantral and antral follicles from the fresh control as well as from all cultured follicles still presented a normal ultrastructural pattern. In medium supplemented with FSH, only insulin at 10 ng/ml presented oocytes with higher rates of meiosis resumption compared to control, as well as oocytes in metaphase II. Treatment with insulin (10 ng/ml) plus FSH resulted in significantly increased levels of INSR and CYP19A1 mRNA compared to that with other treatments. In conclusion, 10 ng/ml insulin associated with FSH was more efficient in promoting resumption of oocyte meiosis, maintaining survival, stimulating follicular development, and increasing expression of the INSR and CYP19A1 genes in goat preantral follicles.