Colesterol carregado pela ciclodextrina sobre a criopreservação dos espermatozoides de garanhões da raça Nordestina / Cholesterol-loaded cyclodextrin on the cryopreservation of stallion sperm of the Northeastern breed

RESUMO

Nesta pesquisa avaliou-se o efeito do colesterol sobre o sêmen de garanhões da raça Nordestina sobre a qualidade espermática. Vinte ejaculados de dois garanhões foram diluídos com BotuSemen e colesterol carreado pela ciclodextrina (CCC) adicionado no sêmen controle, 0,75mg de CCC e 1,0mg de CCC/120x106 sptz/mL, e incubado a 26°C/15min. O sêmen foi diluído 15 (v/v) com diluente Lactose-gema de ovo e resfriado a 5°C/2h, envasado em palhetas de 0,5mL, e acondicionado sob vapor de nitrogênio líquido, e depois imersos. As amostras foram descongeladas (37 °C/30s) e avaliadas. As variáveis foram avaliadas com ANOVA e teste de Tukey (P<0,05). A motilidade total e progressiva foi maior (P<0,05) no sêmen tratado com CCC comparado as amostras do grupo controle, e CCC promoveu maior percentual (P<0,05) de motilidade total e progressiva durante as 3 horas de incubação. A percentagem de espermatozoides com viabilidade e integridade foi maior (P<0,05) no sêmen tratado com CCC (81,47 e 86,07%) comparado ao controle (72,12 e 70,19%). O número de espermatozoides reativos ao teste hiposmótico foi maior (P<0,05) nas amostras de sêmen tratadas com CCC comparado ao controle. Adição de colesterol no sêmen de garanhões Nordestino melhora a qualidade espermática apos a criopreservação.(AU)

ABSTRACT

In the study effect of cholesterol was evaluated on the sperm quality of Nordestina stallion breed. Twenty semen samples were used from two stallions, diluted with BotuSemen extender and cholesterol add as follows control, 0.75mg of cholesterol-loaded cyclodextrin (CLC) and 1.0mg of CLC/120x106 sperm/mL, and incubated for 15 min at 22°C. The samples were diluted 15 with lactose-yolk egg extender and cooled to 5°C over two hours, loaded into 0.5mL straws and frozen in static liquid nitrogen vapor before being plunged into nitrogen. Samples were thawed (37°C/30s) and analyzed. The variables were analyzed by ANOVA and means compared by Tukey test (P<0.05). Higher percentages of total and progressive motile was higher for sperm treated with CLC compared to control, and CLC promoted higher percentages (P<0.05) of total and progressive motility for the 3 hours of incubation. The percentage of viability and plasma membrane integrity of spermatozoa were higher (P<0.05) in sperm treated with CLC compared to the control group. The number of spermatozoa reacted to hypoosmotic test was higher (P<0.05) in sperm treated with CLC than control. Addition of CLC in the semen of Nordestina stallion breed improve the sperm quality after cryopreservation.(AU)