Abstract The aim of this study was to evaluate the effect of green tea extract (GTE) on the spermatic parameters of Wistar rats, submitted or not to testicular heat shock (HS). For this, 48 animals were treated according to the experimental groups (G1: not exposed to HS and untreated; G2: exposed to HS and untreated; G3: not exposed to HS and treated with GTE; G4: exposed to HS and treated with GTE). Subgroups of rats were euthanized on days 15, 30, and 60 to recover the spermatozoa. The total motility (TM), vigor, spermatic morphology and concentration, mitochondrial membrane potential, plasma membrane integrity, and acrosome integrity (ACi) were analyzed. The TM was higher in G1 and G3 than in G2 and G4 on day 30, and higher in G4 on day 60. The overall means of TM and vigor were higher in G1 and G3 than in G2 and G4, as well as TM on day 60. For the morphology, G2 and G4 were lower than G1 and G3 on day 15, and G4 was lower than G1 and G3 on day 30. Moreover, in G1 and G3 morphology was higher on days 15 and 30, and in G4 it was lower on day 30, with the overall means being higher in G1 and G3 than in G2 and G4, as well as on days 15 and 60 compared to day 30. The overall mean of ACi, on day 30, was lower than on days 15 and 60 for all the groups. Therefore, HS is shown to be widely deleterious to the gametes, and the daily administration of 100 mg/kg green tea extract does not improve the spermatic parameters of Wistar rats, submitted or not to testicular HS, although it leads to better recovery of spermatic motility and morphology at 60 days.

Objetivando-se avaliar o efeito de diferentes concentrações dos crioprotetores etileno glicol ou acetamida na viabilidade in vitro de espermatozoides congelados de ovinos, foram utilizados seis pools de sêmen de quatro reprodutores mestiços da raça Santa Inês. Após aprovação, o pool dos ejaculados foi diluído em Tris-gema, acrescido de glicerol (G1=5%; controle), etileno glicol (G2=3%; G3=5%) ou acetamida (G4=2%; G5=7%), envasado em palhetas (0,25mL; 100x106 espermatozoides) e congelado. As amostras descongeladas (37oC/30 segundos) foram avaliadas quanto a motilidade progressiva (MP), vigor, integridade da membrana plasmática (iMP), potencial de membrana mitocondrial (PMM) e integridade do acrossoma (iAC). Constatou-se que a MP do G1 foi superior (P<0,05) à dos G3, G4 e G5, e que o vigor dos G1, G2 e G3 foi maior (P<0,05) do que o dos G4 e G5. A iMP do G1 foi superior (P<0,05) à dos G2, G3, G4 e G5, assim como os G2 e G3 foram superiores (P<0,05) a G4 e G5. O PMM e a iAC não diferiram (P>0,05) entre os grupos. Conclui-se que o etileno glicol (3 e 5%) e a acetamida (2 e 7%) não são eficazes para a proteção dos espermatozoides ovinos submetidos à congelação.

Aiming to evaluate the effect of different concentrations of ethylene glycol or acetamide cryoprotectants on in vitro viability of ram frozen spermatozoa, were used six semen-pools from four Santa Inês crossbred males. After approval, the ejaculate-pool was diluted in Tris egg-yolk plus glycerol (G1=5%; control), ethylene glycol (3%=G2; G3=5%) or acetamide (G4=2%; G5=7%), loaded in straws (0.25mL; 100x106 sperm) and frozeng. Thawed samples (37oC/30 seconds) were evaluated for progressive motility (PM), vigor, plasma membrane integrity (PMi), mitochondrial membrane potential (MMP) and acrosome integrity (ACi). It was found that the PM of G1 was higher (P<0.05) than G3, G4 and G5, and that the vigor of G1, G2 and G3 was higher (P<0.05) than G4 and G5. The PMi of G1 was higher (P<0.05) than G2, G3, G4 and G5, as well as G2 and G3 (P<0.05) where high than G4 and G5. MMP and ACi were not different (P>0.05) among groups. It is concluded that ethylene glycol (3 and 5%) and acetamide (2 and 7%) don't are effectives in protecting ram spermatozoa subjected to freezing.