Efeito da adição de glutationa peroxidase e cisteína ao diluidor de congelação do sêmen equino / Effect of glutathione peroxidase and cysteine addition in an equine frozen semen medium

Foram utilizados ejaculados (n=25) de garanhões para avaliar o efeito de glutationa peroxidase (GPx) e cisteína na viabilidade de espermatozoides congelados. O sêmen foi diluído em Botu Crio, com antioxidantes, e foram formados os grupos: G1, Controle; G2, 1U GPx ; G3, 5U GPx; G4, 0,5mM cisteína; G5, 1mM cisteína. Depois foi envasado em palhetas (0,5mL) e congelado. Após descongelação, 37°C por 30 segundos, alíquotas foram analisadas quanto à integridade de membrana plasmática (IMP) e acrossoma (IAc), potencial de membrana mitocondrial (PMM) e cinética, nos tempos zero (T0) e 60 minutos (T60). GPx 5U e cisteína 0,5mM determinaram maior (P<0,05) IAc em T0 do que em T60. Cisteína 1mM resultou em maior (P<0,05) IAc em T60 do que GPx 1 e 5U e cisteína 0,5mM. O PMM de um garanhão no T60 foi mais alto (P<0,05) do que o de dois garanhões. VCL e VAP foram maiores (P<0,05) no T0 do que no T60 do grupo controle, e um garanhão apresentou, em geral, valores cinéticos mais altos (P<0,05) do que os demais. Conclui-se que a adição de glutationa peroxidase, nas concentrações de 1U e 5U, e de cisteína, nas concentrações de 0,5mM e 1mM, não interferem na integridade de espermatozoides criopreservados de equinos, mas preservam os parâmetros cinéticos de VCL e VAP após 60 minutos de incubação. Ressalta-se, ainda, que o garanhão tem uma forte influência nas características espermáticas pós-congelação.

Ejaculates (n=25) of horses were used to assess the effect of glutathione peroxidase (GPx) and cysteine on the viability of frozen sperm cells. Semen was extended at Botu Crio with antioxidants, and divided in groups: G1, control; G2, 1 U GPx; G3, 5U GPx; G4, 0.5mM cysteine and G5, 1mM cysteine, packed in 0.5mL straws, and frozen. After thawing (37° C for 30 seconds) samples were analyzed for plasma membrane (IMP) and acrosome integrity (IAc), mitochondrial membrane potential (MMP) and kinematic, at zero (T0) and 60 minutes after (T60). GPx 5U and cysteine 0.5mM increased (P<0.05) IAc at T0, when compared to T60. Cysteine 1mM resulted in a higher (P<0.05) IAc on T60, than GPx 1 and 5U, and cysteine 0.5mM. The PMM from a stallion on T60 was higher (P<0.05) than those of two stallions. In sperm kinematic, VCL and VAP were higher (P<0.05) at T0 compared to T60 for the control group, and one stallion showed larger (P<0.05) kinematic values than other animals. It is concluded that the addition of glutathione peroxidase at concentrations 1U and 5U, and cysteine, at concentrations of 0.5mM and 1mM, does not interfere with the integrity of cryopreserved equine sperm, but preserves the kinetic parameters VCL and VAP after 60 minutes of incubation. It should be noted also that the stallion has a strong influence on sperm characteristics post-freezing.

Interferência da condição climática na integridade de espermatozoides ovinos submetidos à criopreservação / Climate condition interference on ram spermatozoa integrity submitted to cryopreservation

Avaliou-se a integridade de espermatozoides ovinos colhidos e criopreservados em diferentes situações climáticas na região semiárida do estado da Paraíba. As colheitas de sêmen foram realizadas em duas épocas do ano, período seco e período chuvoso, utilizando cinco machos adultos da raça Santa Inês, com histórico favorável de fertilidade. Os ejaculados foram avaliados quanto à motilidade, vigor, concentração e morfologia espermática, após a formação do pool e diluição em Tris-gema, na concentração final de 240x10(6) espermatozoides/mL. Motilidade total e vigor espermático não diferiram entre as épocas seca e chuvosa. Valores de integridade do acrossoma e da membrana plasmática, e o potencial de membrana mitocondrial foram mais baixos (P<0,05) na época com menor índice pluviométrico. Conclui-se que a reprodução de ovinos criados na região do semiárido paraibano sofre ação da condição climática e sugere-se que a criopreservação de espermatozoides ovinos seja realizada no período de maior índice pluviométrico na região.

Ram spermatozoa integrity collected and cryopreserved in different climatic situations in the semiarid region of Paraíba state was evaluated. Semen samples were collected in two periods: a dry and a rainy season, using five mature Santa Inês males, with favorable historical fertility. Ejaculates were evaluated for motility, vigor, concentration and morphology, after a pool formation and dilution in Tris-yolk egg, at 240x10(6)/mL final concentration. Motility and sperm vigor did not differ between dry and rainy seasons. Acrosome integrity, plasma membrane and mitochondrial membrane potential were lower (P>0.05) at the time with less rainfall. We concluded that sheep reproduction raised in semi-arid Paraiba region suffers climatic condition influence and the lowest rainfall period is deleterious to the sperm cells integrity subjected to cryopreservation process. It is suggested that ram spermatozoa cryopreservation be done in period of greatest rainfall in this region.

Acute hepatitis due to dengue virus in a chronic hepatitis patient

We present a case of acute hepatitis caused by dengue virus, with a significant increase in aspartate transferase and alanine transferase levels in a chronic hepatitis patient attended at the Cane Sugar Planters Hospital of Campos dos Goytacazes, RJ.

Effect of Ginkgo biloba on the reproductive outcome and oxidative stress biomarkers of streptozotocin-induced diabetic rats

The aim of the present study was to evaluate the effect of Ginkgo biloba treatment (EGb 761, 200 mg kg-1 day-1) administered from day 0 to 20 of pregnancy on maternal reproductive performance and on the maternal and fetal liver antioxidant systems of streptozotocin-induced diabetic Wistar rats. On day 21 of pregnancy, the adult rats (weighing approximately 250 ± 50 g, minimum number = 13/group) were anesthetized to obtain maternal and fetal liver samples for superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total glutathione (GSH-t) determinations. The uterus was weighed with its contents. The diabetic (G3) and treated diabetic (G4) groups of rats presented significant maternal hyperglycemia, reduced term pregnancy rate, impaired maternal reproductive outcome and fetal-placental development, decreased GSH-Px (G3 = G4 = 0.6 ± 0.2) and SOD (G3 = 223.0 ± 84.7; G4 = 146.1 ± 40.8), and decreased fetal CAT activity (G3 = 22.4 ± 10.6; G4 = 34.4 ± 14.1) and GSH-t (G3 = G4 = 0.3 ± 0.2), compared to the non-diabetic groups (G1, untreated control; G2, treated). For G1, maternal GSH-Px = 0.9 ± 0.2 and SOD = 274.1 ± 80.3; fetal CAT = 92.6 ± 82.7 and GSH-t = 0.6 ± 0.5. For G2, G. biloba treatment caused no toxicity and did not modify maternal or fetal-placental data. EGb 761 at the nontoxic dose used (200 mg kg-1 day-1), failed to modify the diabetes-associated increase in maternal glycemia, decrease in pregnancy rate, decrease in antioxidant enzymes, and impaired fetal development when the rats were treated throughout pregnancy (21 days).

Genetic differentiation in geographically close populations of the water rat Nectomys squamipes (Rodentia, Sigmodontinae) from the Brazilian Atlantic Forest

We examined the genetic structure and the effects of a bottleneck in populations of the water rat Nectomys squamipes, a primary host of Schistosoma mansoni. Eight microsatellite loci were studied in 7 populations from the Sumidouro region of the Brazilian state of Rio de Janeiro. Our data, covering a four-year period during which a bottleneck occurred, revealed substantial variation (6-31 alleles per locus) and high levels of both observed (0.718-0.789) and expected (0.748-0.832) heterozygosity. Most populations were in Hardy-Weinberg equilibrium without linkage disequilibrium between loci. Overall average genetic differentiation between populations (estimated with the F ST (theta) and R ST (rho) analogues was 0.037 for theta and 0.060 for rho. There was significant allelic and genotypic differentiation between populations, especially in pairwise comparisons that included the most geographically isolated population. Direct migration estimates showed a low rate of migration, indicating that infected N. squamipes populations had a limited ability to spread S. mansoni. When the pre- and post-bottleneck populations were compared there was no detectable reduction in heterozygosity or allele number, although a significant excess of heterozygosity was detected in the post-bottleneck population.