O efeito da hCG, eCG e pFSH sobre as características morfológicas e funcionais do corpo lúteo de cabras após a indução do estro sincronizado
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Data
2018-06-25
Autores
Trevizan, Juliane Teramachi [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O presente estudo testou a hipótese de que a hCG e pFSH estimulam o desenvolvimento folicular e de corpos lúteos, equivalente aos induzidos pela eCG em fêmeas caprinas. Cento e quinze cabras Toggenburg foram dividas e submetidas ao protocolo de curta duração (60 mg MAP, 6 dias; Dia - 8) durante o período sazonal de transição. Cada grupo recebeu 24 hs antes da remoção da esponja 22.5 µg d – cloprostenol e 200 UI eCG, ou 300 UI hCG ou 30 UI pFSH. A dinâmica folicular (n = 85 cabras) foi realizada desde o momento da aplicação da gonadotrofina (Dia – 3) até a detecção da ovulação. O início do estro (Dia 0) foi monitorada para avalição do comportamento estral. As variáveis biométricas e vasculares do corpo lúteo (CL: área, diâmetro, volume, ecogeneidade, heterogeneidade, escore de vascularização e número de pixels coloridos) entre cabras prenhes e não prenhes foram avaliadas em momentos específicos (Dia 5, 8, 13, 18, 23 e 28) pela ultrassonografia bidimensional (Modo B) e Doppler Colorido. O diagnóstico de gestação foi confirmado pela detecção da vesícula embrionária, realizada sobre o Dia 28. O diâmetro do maior folículo no dia da aplicação da gonadotrofina e o tempo para o alcance do diâmetro máximo do folículo dominante foi maior e mais precoce no grupo eCG (P = 0,024 e P = 0,002; respectivamente). Cabras tratadas com eCG e pFSH apresentaram maiores dimensões foliculares (P = 0,003) e hCG, maior número de folículos ovulatórios (P = 0,004) e corpos lúteos (P = 0,0001). A ovulação ocorreu mais rápida no grupo eCG, mas todos os grupos apresentaram tempo similar entre o início do estro e ovulação (P = 0,048). Corpos lúteos de cabras prenhes do grupo hCG apresentaram diâmetro (P = 0,043) e volume (P = 0,046) menores sobre o Dia 18 (P = 0,001). A ecogeneidade do CL de cabras prenhes foi alta em todos os grupos sobre o Dia 28, comparado as avaliações iniciais (Dia 5 e 8) e baixa em CL de cabras não prenhes a partir do Dia 18 (P = 0,001). A heterogeneidade e vascularização do CL de cabras prenhes e não prenhes não foi influenciada pela interação entre tratamentos e dia da avaliação (P > 0,05). Mas independente do tratamento, CLs de cabras prenhes apresentaram maior heterogeneidade e maior área de vascularização ao longo dos dias de avaliação (P = 0,001). Ao contrário, CLs de cabras não prenhes mostraram redução dos valores de vascularização e heterogeneidade a partir do Dia 18 e 23, respectivamente (P < 0,001). A taxa de concepção média foi de 65,76 % e taxa de de prenhez equivalente a 62,72 %, não diferindo entre os grupos experimentais. A hCG e pFSH são equivalentes à eCG na indução da resposta ao estro, na taxa de ovulação, concepção e prenhez, entretanto há diferenças na dinâmica folicular e luteal. O curto intervalo de tempo entre a remoção da esponja e ovulação observado no grupo eCG, provavelmente está relacionada ao maior diâmetro do maior folículo no dia da aplicação da gonadotrofina. Desta forma, diferenças encontradas nas dimensões foliculares entre os grupos não estão exclusivamente relacionadas ao tipo de gonadotrofina, mas com o status folicular no momento da administração da gonadotrofina. Independente, hCG e pFSH foram capazes de promover o desenvolvimento folicular adequado, visto que o diâmetro do maior folículo ovulatório foram similares de cabras tratadas com eCG. Quanto as diferenças encontradas nas características biométricas e ecogênicas dos CLs, estas devem-se a maior capacidade ovulatória da hCG, que por sua vez resultaram em CLs de menor diâmetro e volume e maior valor de pixel de ecogeneidade. No entanto, estes achados não se rementem a uma anormalidade, desde que as mudanças morfológicas do CL ao longo dos dias das avaliações foram evidenciadas entre os grupos e as alterações vasculares foram distintas apenas com relação a categoria do CL (prenhe e não prenhe).
The present study tested the hypothesis that hCG and pFSH stimulate follicular and corpora lutea growth, equivalent to those induced by the eCG in goat females. Toggenburg goats (n = 115) were divided and submitted to the short duration protocol (60 mg MAP, 6 days; Day – 8) during the seasonal transition period. Each group received 22.5 µg d – cloprostenol and 200 IU eCG, or 300 IU hCG or 30 UI pFSH, 24 hours before the sponge removal. The follicular dynamics (n = 85 goats) were performed from the moment of the application of gonadotropin (Day - 3) until the detection of ovulation. The onset of estrus (Day 0) was monitored for evaluation of estrus behavior. The biometric and vascular variables of the corpus luteum (CL: area, diameter, volume, ecogeneity, heterogeneity, vascularization score and number of colored pixels) between pregnant and non-pregnant goats were evaluated at specific times (Day 5, 8, 13, 18, 23 and 28) by two-dimensional ultrasound (Mode B) and Color Doppler. The pregnancy diagnosis was confirmed by detection of the embryonic vesicle performed on Day 28. The diameter of the largest follicle on the day of application of gonadotrophin and the time to reach the maximum diameter of the dominant follicle was higher and earlier in the eCG group (P = 0.024 and P = 0.002, respectively). Goats treated with eCG and pFSH presented greater follicular dimensions (P = 0.003) and hCG, greater number of ovulatory follicles (P = 0.004) and corpora lutea (P = 0.0001). Ovulation occurred faster in the eCG group, but all groups showed similar time between the onset of estrus and ovulation (P = 0.048). Luteal bodies of pregnant goats of the hCG group presented smaller diameter (P = 0.043) and volume (P = 0.046) on Day 18 (P = 0.001). The ecogeneity of CL in pregnant goats was high in all groups on Day 28, compared to initial evaluations (Day 5 and 8) and low in CL of non-pregnant goats from Day 18 (P = 0.001). The heterogeneity and vascularization of CL from pregnant and non-pregnant goats was not influenced by the interaction between treatments and day of the evaluation (P> 0.05). However, regardless of the treatment, CLs of pregnant goats showed greater heterogeneity and greater area of vascularization during the evaluation days (P = 0.001). Unlike, CLs from non-pregnant goats showed reduced values of vascularization and heterogeneity from Day 18 and 23, respectively (P <0.001). The mean conception rate was 65.76% and the pregnancy rate was 62.72%, not differing between the experimental groups. hCG and pFSH are equivalent to eCG in inducing estrus response, ovulation rate, conception and pregnancy, however there are differences in follicular and luteal dynamics. The short interval between sponge removal and ovulation observed in the eCG group is probably related to the larger diameter of the largest follicle on the day of gonadotrophin application. Thus, differences in follicular dimensions between groups are not exclusively related to the type of gonadotrophin, but to the follicular status at the time of administration of gonadotrophin. Independent, hCG and pFSH were able to promote adequate follicular development, since the diameter of the largest ovulatory follicle were similar for goats treated with eCG. As for the differences in the biometric and echogenic characteristics of CLs, these are due to the greater ovulatory capacity of hCG, which in turn resulted in CLs of smaller diameter and volume and higher pixel value of ecogeneity. However, these findings do not reimpose an abnormality, since the morphological changes of CL throughout the days of the evaluations were evidenced between the groups and the vascular alterations were distinct only with respect to CL category (pregnant and not pregnant).
The present study tested the hypothesis that hCG and pFSH stimulate follicular and corpora lutea growth, equivalent to those induced by the eCG in goat females. Toggenburg goats (n = 115) were divided and submitted to the short duration protocol (60 mg MAP, 6 days; Day – 8) during the seasonal transition period. Each group received 22.5 µg d – cloprostenol and 200 IU eCG, or 300 IU hCG or 30 UI pFSH, 24 hours before the sponge removal. The follicular dynamics (n = 85 goats) were performed from the moment of the application of gonadotropin (Day - 3) until the detection of ovulation. The onset of estrus (Day 0) was monitored for evaluation of estrus behavior. The biometric and vascular variables of the corpus luteum (CL: area, diameter, volume, ecogeneity, heterogeneity, vascularization score and number of colored pixels) between pregnant and non-pregnant goats were evaluated at specific times (Day 5, 8, 13, 18, 23 and 28) by two-dimensional ultrasound (Mode B) and Color Doppler. The pregnancy diagnosis was confirmed by detection of the embryonic vesicle performed on Day 28. The diameter of the largest follicle on the day of application of gonadotrophin and the time to reach the maximum diameter of the dominant follicle was higher and earlier in the eCG group (P = 0.024 and P = 0.002, respectively). Goats treated with eCG and pFSH presented greater follicular dimensions (P = 0.003) and hCG, greater number of ovulatory follicles (P = 0.004) and corpora lutea (P = 0.0001). Ovulation occurred faster in the eCG group, but all groups showed similar time between the onset of estrus and ovulation (P = 0.048). Luteal bodies of pregnant goats of the hCG group presented smaller diameter (P = 0.043) and volume (P = 0.046) on Day 18 (P = 0.001). The ecogeneity of CL in pregnant goats was high in all groups on Day 28, compared to initial evaluations (Day 5 and 8) and low in CL of non-pregnant goats from Day 18 (P = 0.001). The heterogeneity and vascularization of CL from pregnant and non-pregnant goats was not influenced by the interaction between treatments and day of the evaluation (P> 0.05). However, regardless of the treatment, CLs of pregnant goats showed greater heterogeneity and greater area of vascularization during the evaluation days (P = 0.001). Unlike, CLs from non-pregnant goats showed reduced values of vascularization and heterogeneity from Day 18 and 23, respectively (P <0.001). The mean conception rate was 65.76% and the pregnancy rate was 62.72%, not differing between the experimental groups. hCG and pFSH are equivalent to eCG in inducing estrus response, ovulation rate, conception and pregnancy, however there are differences in follicular and luteal dynamics. The short interval between sponge removal and ovulation observed in the eCG group is probably related to the larger diameter of the largest follicle on the day of gonadotrophin application. Thus, differences in follicular dimensions between groups are not exclusively related to the type of gonadotrophin, but to the follicular status at the time of administration of gonadotrophin. Independent, hCG and pFSH were able to promote adequate follicular development, since the diameter of the largest ovulatory follicle were similar for goats treated with eCG. As for the differences in the biometric and echogenic characteristics of CLs, these are due to the greater ovulatory capacity of hCG, which in turn resulted in CLs of smaller diameter and volume and higher pixel value of ecogeneity. However, these findings do not reimpose an abnormality, since the morphological changes of CL throughout the days of the evaluations were evidenced between the groups and the vascular alterations were distinct only with respect to CL category (pregnant and not pregnant).
Descrição
Palavras-chave
Doppler Colorido, Ecogeneidade, Heterogeneidade, Ultrassonografia, Color Doppler, Ecogeneity