Protocolos de indução hormonal com extrato bruto de hipófises de carpa e o perfil da prostaglandina F2α durante a maturação final e ovulação em Astyanax altiparanae
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Data
2019-02-25
Autores
Figueiredo-Ariki, Daniel Guimarães [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Considerando as inconsistentes informações acerca dos protocolos de indução hormonal do Astyanax altiparanae em cativeiro, o principal objetivo deste estudo foi comparar o desempenho reprodutivo utilizando ou não extrato bruto de hipófise de carpa (EBHC). Avaliamos também o efeito de diferentes doses de EBHC sobre o desempenho reprodutivo em dois distintos lotes de peixes. Em todos os experimentos, avaliamos se um eventual ganho no desempenho reprodutivo estaria associado com alterações na morfologia dos ovários e/ou com concentrações séricas de prostaglandina F2α (PGF2α). Nos experimentos 1 (lote capturado na natureza) e 2 (lote nascido em cativeiro), aplicamos 3, 6 e 9 mg.kg-1 de EBHC (T1, T2 e T3 respectivamente), e um grupo controle (C). No experimento 3 (mesmo lote do experimento 2), comparamos o desempenho reprodutivo com dose única e fracionada (10% e 90% da dose total, com intervalo de 12 horas entre as doses) de EBHC, sendo 6 mg.kg-1 em dose única (H1) ou fracionada (H2) e seus respectivos controles (C1 e C2). Nos experimentos 1 e 2 o desempenho reprodutivo foi similar entre os grupos, porém os grupos T2 e T3 apresentaram elevações de PGF2α no momento da ovulação, além de variações significativas nas frequências de estruturas ovarianas, que indicam aumento da ovulação e /ou a maturação final. No experimento 3, a dose fracionada de 6 mg.kg-1 de EBHC causou um aumento na proporção de réplicas com desova e consequentemente, no volume total de desova e no número total de embriões viáveis. Esta dose também causou um aumento na frequência de complexos pós ovulatórios e no nível de PGF2α no momento da desova. Concluímos que a indução hormonal pode potencializar a desova do lambari. Os reprodutores dos diferentes lotes apresentaram um padrão similar de resposta ao tratamento com EBHC. O fracionamento da dose de EBHC propiciou melhor desempenho que a dose única, o qual, porém, só ficou evidente em análises histológicas e de concentrações de PGF2α. Portanto, recomendamos o uso da dose fracionada de 6 mg.kg-1 de EBHC para indução hormonal desta espécie em cativeiro, usando as condições aqui aplicadas.
Considering the inconsistent information about the hormonal induction protocols of Astyanax altiparanae in captivity, the main objective of this study was to compare the reproductive performance with or without crude carp pituitary extract (EBHC). We also evaluated the effect of different doses of EBHC on the reproductive performance of two distinct broodstocks. In all experiments, we evaluated whether a possible gain in reproductive performance would be associated with changes in ovarian morphology and / or with serum prostaglandin F2α (PGF2α) concentrations. In the experiments 1 (wild caught) and 2 (born in captivity), we applied 3, 6 and 9 mg.kg-1 EBHC (T1, T2 and T3 respectively), and one control group (C). In the experiment 3 (same broodstock as in experiment 2), we compared reproductive performance with single and fractional doses (10% e 90% of the total, with 12 hours of interval between doses) of EBHC, being: 6 mg.kg-1 in single dose (H1) or fractional (H2) and their respective controls (C1 and C2). In the experiments 1 and 2 the reproductive performance was similar between groups, but groups T2 and T3 presented elevations of PGF2α at the time of ovulation, besides significant variations in the frequencies of ovarian structures, which indicates increase in ovulation and / or final maturation. In the experiment 3, the fractional dose of 6 mg.kg-1 EBHC caused an increase in the proportion of replicates with spawn events and consequently, in the total volume of eggs and the absolute number of viable embryos. This dose also caused an increase in the frequency of post ovulatory complexes and the level of PGF2α at spawning time. We conclude that the hormonal induction can potentialize the spawning of lambari. Different broodstock presented a similar pattern of response to EBHC treatment. The fractioning of the EBHC doses gave better performance than the single dose, but, however, was only evident in histological and PGF2α concentrations analyzes. Therefore, we recommend the use of the fractional dose of 6 mg.kg-1 of EBHC for hormonal induction of this species in captivity, using the conditions applied herein.
Considering the inconsistent information about the hormonal induction protocols of Astyanax altiparanae in captivity, the main objective of this study was to compare the reproductive performance with or without crude carp pituitary extract (EBHC). We also evaluated the effect of different doses of EBHC on the reproductive performance of two distinct broodstocks. In all experiments, we evaluated whether a possible gain in reproductive performance would be associated with changes in ovarian morphology and / or with serum prostaglandin F2α (PGF2α) concentrations. In the experiments 1 (wild caught) and 2 (born in captivity), we applied 3, 6 and 9 mg.kg-1 EBHC (T1, T2 and T3 respectively), and one control group (C). In the experiment 3 (same broodstock as in experiment 2), we compared reproductive performance with single and fractional doses (10% e 90% of the total, with 12 hours of interval between doses) of EBHC, being: 6 mg.kg-1 in single dose (H1) or fractional (H2) and their respective controls (C1 and C2). In the experiments 1 and 2 the reproductive performance was similar between groups, but groups T2 and T3 presented elevations of PGF2α at the time of ovulation, besides significant variations in the frequencies of ovarian structures, which indicates increase in ovulation and / or final maturation. In the experiment 3, the fractional dose of 6 mg.kg-1 EBHC caused an increase in the proportion of replicates with spawn events and consequently, in the total volume of eggs and the absolute number of viable embryos. This dose also caused an increase in the frequency of post ovulatory complexes and the level of PGF2α at spawning time. We conclude that the hormonal induction can potentialize the spawning of lambari. Different broodstock presented a similar pattern of response to EBHC treatment. The fractioning of the EBHC doses gave better performance than the single dose, but, however, was only evident in histological and PGF2α concentrations analyzes. Therefore, we recommend the use of the fractional dose of 6 mg.kg-1 of EBHC for hormonal induction of this species in captivity, using the conditions applied herein.
Descrição
Palavras-chave
PGF2α, Lambari, Hipofisação, Indução hormonal, Prostaglandina