The effect of glycosaminoglycans, extracted from the skin of tilapia, in the sperm freezing medium of Colossoma macropomum.

BACKGROUND: Sulfated polysaccharides from the skin of Nile tilapia (Oreochromis niloticus), added to the tambaqui (Colossoma macropomum) semen diluting medium, can be potential antioxidants and promote the maintenance of sperm quality. OBJECTIVE: To evaluate the use of different concentrations of glycosaminoglycans (GAGs) from the skin of Nile tilapia as a supplement in two cryogenic media for tambaqui semen. MATERIALS AND METHODS: Tambaqui males received a single dose of pituitary carp extract. The semen was collected for pool analysis and, later, cryopreserved in liquid nitrogen. The pools were diluted and frozen in a solution containing fish-specific powdered coconut water (ACP-104) and 10% DMSO or 5% Glucose and 10% DMSO and supplemented with different concentrations of GAGs. The controls had no GAGs addition. After 45 days, the samples were thawed by immersion in a water bath and evaluated for membrane and DNA integrity, morphology and sperm kinetics. RESULTS: The parameters of linearity (LIN), straightness (STR) and DNA integrity of sperm frozen in 5% Glucose showed better results than ACP-104. For membrane integrity, concentrations of 0 and 1.0 mg/mL were better than 5 mg/mL. Semen motility in 5% Glucose showed superior results at concentrations lower than 5 mg/mL of GAGs. For VCL and VAP, in ACP-104, 3.0 mg/mL exceeded the other treatments. In 5% Glucose, for VCL, 4.0 mg/mL showed the lowest results compared to concentrations of <3.5 mg/mL and, for VAP, it also differed from 4.5 mg/mL CONCLUSION: Therefore, the skin of Nile tilapia has GAGs, in low concentrations, capable of improving the post-thawed sperm quality of tambaqui, especially in 5% Glucose medium.

Efeito de vitaminas adicionadas ao diluente ACP-104 sobre a qualidade do sêmen criopreservado de carpa comum (Cyprinus carpio) / Effect of vitamins added to the ACP-104 extender on the quality of cryopreserved semen of common carp (Cyprinus carpio)

O objetivo da presente pesquisa foi alcançado com a divisão da pesquisa em dois experimentos: (1) aperfeiçoar o protocolo de congelação utilizando água de coco em pó (ACP-104) como diluente para a criopreservação seminal de carpa comum; (2) avaliar o efeito da suplementação das vitaminas C (ácido ascórbico) ou E (α-tocoferol) sobre os melhores diluidores testados no experimento 1 na qualidade do sêmen pós-descongelado da espécie. Para o experimento 1, foram formados oito pools de sêmen, provenientes de 14 machos selecionados. As amostras seminais coletadas foram avaliadas quanto à motilidade total, à velocidade, ao percentual de espermatozoides normais e à vitalidade espermática antes e depois da criopreservação seminal. Esta foi realizada em meio ACP-104 acrescido de dimetilsulfóxido (DMSO), ou etilenoglicol (EG), ou glicerol, ou metanol, todos à concentração de 10%, diluídos em 1:3 (sêmen:diluidor). As amostras foram, então, congeladas em vapor de nitrogênio líquido em dry shipper e estocadas em nitrogênio líquido (-196°C). Para o experimento 2, foram formados oito pools provenientes da coleta de sêmen de 15 machos. As amostras seminais foram avaliadas seguindo as mesmas análises do experimento 1, acrescentando-se a duração da motilidade total. A criopreservação seminal utilizou-se do meio ACP-104 acrescido de DMSO ou EG, suplementado ou não com vitamina C ou E. Os melhores resultados encontrados no experimento 1 foram obtidos com o DMSO e o EG. Estes não diferiram significativamente entre si para a motilidade total (24% e 28%; P>0,05) e a normalidade espermática (32% e 26%; P>0,05), respectivamente. Para o experimento 2, o EG suplementado com vitamina E produziu significativamente resultados superiores de motilidade total, normalidade espermática e duração da motilidade em relação ao DMSO, concluindo-se que o EG deve ser, portanto, o crioprotetor de escolha a ser utilizado com o ACP-104 suplementado ou não com vitamina E.(AU)

The objective was achieved by dividing the research into two experiments: (1) improving the freezing protocol using powdered coconut water (ACP-104) as a diluent for the cryopreservation seminal of common carp; (2) evaluating the effect of supplementation of vitamins C (ascorbic acid) or vitamin E (α-tocoferol) with the best extenders tested in experiment 1 on the quality of post-thawed. For experiment 1, semen pools from 14 selected males were formed. Seminal samples were evaluated for total motility, velocity, percentage of normal sperm and sperm vitality before and after the seminal cryopreservation. This was done in ACP-104 extender plus dimethyl sulfoxide (DMSO), or ethylene glycol (EG), or glycerol or methanol all at concentration 10% diluted in 1:3 (semen:extender). The samples were frozen in vapors of nitrogen into dry shippers and stored in liquid nitrogen (-196 °C). For experiment 2, eight pools were formed from the 15 males. The semen samples were evaluated following the same analysis of experiment 1 adding duration of total motility. The sperm cryopreservation was performed in extenders ACP-104 plus DMSO or EG supplemented or not with vitamin C or E. The best results found in Experiment 1 were obtained with DMSO and EG. They do not differ significantly for total motility (24% and 28%; P>0.05) and normal sperm (32% and 26%; P>0.05) respectively. For experiment 2, EG supplemented with vitamin E, produced significantly better results overall motility, sperm normality and duration of motility relative to DMSO. In conclusion, EG should be the cryoprotectant of choice for use with the ACP-104 supplemented or not with vitamin E.(AU)