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.

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.

The objective this study was to determine the effect of phytohemagglutinin (PHA) on survival, growth and gene expression in caprine secondary follicles culturedin 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.