The cryopreservation protocols are species‐specific owing to variable sperm sensitivity towards temperature reduction and contact with cryoprotectant solutions. However, little is known about spermatic pathologies, especially after the cryopreservation process. Thus, the objective was to evaluate the effect of cryopreservation on morphological changes in semen of jundiá (Rhamdia quelen). Sperm pool of five males, with >80% motility, as collected, diluted in a cryoprotectant solution and frozen in liquid nitrogen (−196°C). There was a reduction in the percentage of normal cells and sperm motility, accompanied by an increase in the percentage of sperm abnormalities after cryopreservation of R. quelen spermatozoa, indicating a substantial fragility of the spermatozoa towards the cryopreservation process. The most frequent types of morphological changes in the cryopreserved semen were macrocephaly, folded tail, strongly curled tail and distally curled tail. This is the first study to evaluate the spermatic morphology of R. quelen before and after cryopreservation, paving way for further investigations on morphological alterations and for a new classification of these changes in fish semen due to cryopreservation.
The cryopreservation promotes cellular damage that could compromise sperm quality in terms of motility and fertility rates, which may be caused by oxidative stress. Thus, the aim of this study was to assess the effects of cysteine addition on post‐thaw sperm quality, DNA damage and indices of oxidative stress of the South American silver catfish (Rhamdia quelen) sperm, compared with the cryoprotectant solution without cysteine addition. Sperm collected from five males were cryopreserved in cryoprotectant solution (fructose 50 g/L, powdered milk 50 g/L and methanol 100 ml/L) containing different cysteine concentrations (0, 2.5, 5, 10 and 20 mM). After thawing, the following were measured: sperm motility, morphology, sperm viability, DNA damage, lipid peroxidation, concentration of carbonyl and sulfhydryl groups and the activity of SOD, CAT, GST and GPx enzymes. The lowest sperm motility was determined for semen cryopreserved with addition of 20 mM of cysteine. The control group had the lowest DNA damage and lipid peroxidation. The findings of this study show that cysteine addition had no positive effect on evaluated parameters. Therefore, the concentrations tested are not recommended for the supplementation of cryoprotectant solution for semen of R. quelen.
O presente trabalho teve como foco a elaboração de um macarrão adicionado de farinha de casca de maracujá, visando comparar os resultados da determinação de componentes nutricionais (umidade, proteínas, lipídios, fibras, minerais e carboidratos) com uma alimentação mais saudável. Os frutos foram obtidos na região metropolitana de Curitiba e o macarrão produzido de acordo com receita a base de farinha de trigo e ovos, sendo adicionada cerca de 7 % de farinha de casca de maracujá. Os testes de determinação nutricional comprovaram uma boa quantidade de fibras no produto final, caracterizando assim uma possível alternativa para uma alimentação mais saudável. Também foi realizada avaliação das características sensoriais do produto, que apresentou resultados medianos, considerados suficientes para o que diz respeito a esse trabalho.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.