Avaliação da eficiência luteolítica de diferentes doses de cloprostenol sódico e dinoprost trometamina administradas nos dias 4 e 11 do ciclo estral de fêmeas bovinas de corte
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Data
2019-08-01
Autores
Nascimento, Gabriel Artur Marciano do
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Universidade Estadual Paulista (Unesp)
Resumo
No presente estudo os objetivos foram avaliar a resposta luteolítica de meia dose (50%) ou dose inteira (100%) de cloprostenol sódico (CS) e dinoprost trometamina (DT) administrados em fêmeas bovinas de corte não lactantes cíclicas, nas fases de metaestro e diestro do ciclo estral (4 ou 11 dias após a ovulação (D0), respectivamente), quanto a: dinâmica luteínica, vascularização central e periférica, quantificação de pixels na área vascularizada do CL e dosagem de progesterona sérica (Exp.1) e morfometria das células luteínicas, imunomarcação de caspase-3 e dosagem de progesterona (P4; Exp.2). No Exp. 1, 54 fêmeas tiveram a ovulação sincronizada e receberam os seguintes tratamentos: CS 0 µg (CS0%; n=3/ grupo), CS 250 µg (CS50%; n=5/D4 e n=7/D11), CS 500 µg (CS100%; n=5/ grupo), DT 0 mg (DT0%; n=2/ grupo), DT 12,5 mg (DT50%; n=5/D4 e n=6/D11) ou DT 25 mg (DT100%; n=5/D4 e n=6/D11). No Exp. 2, 25 fêmeas foram sincronizadas, alocadas nos tratamentos no D4 e D11: CS50%; CS100%; DT50%; DT100% (n=3/ grupo, exceto DT100% no D11, n=2) e abatidas dois dias após. Os dados foram analisados por ANOVA em arranjo fatorial (2x2x3, no Exp. 1 e 2x2x2, no Exp. 2) com medidas repetidas no tempo (exceto para morfometria e imunomarcação) e teste de Tukey, com significância a 5%. No Exp. 1, animais avaliados no D4 apresentaram redução numérica da concentração de P4, das dimensões e vascularização luteais. Já animais avaliados a partir de D11 apresentaram redução para todos os parâmetros avaliados ao longo dos momentos experimentais. A utilização de 50% ou 100% da dose dos luteolíticos causaram redução semelhante nas variáveis avaliadas comparados ao controle negativo. No Exp. 2, o número de células luteais pequenas imunomarcadas para caspase-3 foi semelhante entre os tratamentos, sendo em maior número quando administradas no D11. Animais tratados com 50% da dose apresentaram maior número de células luteais grandes comparados aos tratados com 100% da dose. Para a área das células luteais grandes, os tratamentos administrados no D11 influenciaram de maneira semelhante esta variável, enquanto que no D4 a menor área foi detectada para animais tratados com CS100%. Animais tratados com CS e com 100% da dose dos ativos no D4 apresentaram maior área de células luteais pequenas. Animais tratados com DT50% apresentaram menor área de células luteais pequenas. A administração dos tratamentos em D4 e D11 causou redução na concentração de P4. A principal diferença observada após a administração de CS e DT ocorreu no efeito exercido pelos ativos sobre as células luteais grandes e pequenas. As dimensões luteais, a vascularização do CL e as concentrações séricas de P4 foram semelhantes após a administração dos ativos avaliados. A administração dos luteolíticos em D4 foi sugestiva de luteólise parcial. Já a administração no D11 foi eficiente em induzir luteólise completa. No presente trabalhou demonstrou-se também a capacidade luteolítica do uso de 50% da dose de CS e DT, quando administradas no D11.
In the present study the objectives were to evaluate the luteolytic response of half-dose (50%) or full dose (100%) of sodium cloprostenol (SC) and dinoprost tromethamine (DT) administered in beef cattle cyclic non-lactating, at the metaestrous and diestrous stages of the estrous cycle (4 or 11 days after ovulation (D0), respectively), regarding: luteal dynamics, central and peripheral vascularization, quantification of pixels in vascularized area of CL and serum progesterone levels (Exp.1) and luteal cell morphometry, caspase-3 immunolocation and progesterone levels (P4; Exp.2). In Exp. 1, 54 females were synchronized ovulation and received the following treatments: SC0µg (SC0%; n=3/group), SC250µg (SC50%; n=5/D4 and n=7/D11), SC500µg (SC100%; n=5/group), DT0mg (DT0%; n=2/group), DT12.5mg (DT50%; n=5/D4 and n=6/D11) or DT25mg (DT100%; n=5/D4 and n=6/D11). In Exp. 2, 25 females were synchronized, assigned to treatments on D4 and D11: SC50%; SC100%; DT50%; DT100% (n=3/group, except DT100% on D11, n=2) and slaughtered two days later. Data were analyzed by ANOVA in factorial arrangement (2x2x3, in Exp. 1 and 2x2x2, in Exp. 2) with repeated measures in time (except for morphometry and immunolocation) and Tukey test, at 5% level of significance. In Exp. 1, animals evaluated in D4 showed numerical reduction of P4 levels, luteal dimensions and vascularization. Animals evaluated at D11 showed reduction for all parameters evaluated over the experimental moments. The use of 50% or 100% of the luteolytic dose caused a similar reduction in the evaluated variables compared to the negative control. In Exp. 2, the number of caspase-3 immunostained small luteal cells was similar between treatments, and large when administered on D11. Animals treated with 50% of the dose presented larger number of large luteal cells compared to those treated with 100% of the dose. For the area of large luteal cells, treatments administered on D11 influenced this variable similarly, while at D4 the smallest area was detected for animals treated with SC100%. Animals treated with SC and with 100% of the dose on D4 showed larger area of small luteal cells. Animals treated with DT50% had smaller area of small luteal cells. Administration of treatments on D4 and D11 caused a reduction in P4 levels. The main difference observed after administration of SC and DT occurred in the effect exerted by the actives on the large and small luteal cells. Luteal dimensions, CL vascularization and serum P4 levels were similar after administration of the luteolytics agents. Administration of luteolytics on D4 was suggestive of partial luteolysis. The administration on D11 was efficient in inducing complete luteolysis. The study also demonstrated the luteolytic ability to use 50% of the dose of SC and DT when administered in D11.
In the present study the objectives were to evaluate the luteolytic response of half-dose (50%) or full dose (100%) of sodium cloprostenol (SC) and dinoprost tromethamine (DT) administered in beef cattle cyclic non-lactating, at the metaestrous and diestrous stages of the estrous cycle (4 or 11 days after ovulation (D0), respectively), regarding: luteal dynamics, central and peripheral vascularization, quantification of pixels in vascularized area of CL and serum progesterone levels (Exp.1) and luteal cell morphometry, caspase-3 immunolocation and progesterone levels (P4; Exp.2). In Exp. 1, 54 females were synchronized ovulation and received the following treatments: SC0µg (SC0%; n=3/group), SC250µg (SC50%; n=5/D4 and n=7/D11), SC500µg (SC100%; n=5/group), DT0mg (DT0%; n=2/group), DT12.5mg (DT50%; n=5/D4 and n=6/D11) or DT25mg (DT100%; n=5/D4 and n=6/D11). In Exp. 2, 25 females were synchronized, assigned to treatments on D4 and D11: SC50%; SC100%; DT50%; DT100% (n=3/group, except DT100% on D11, n=2) and slaughtered two days later. Data were analyzed by ANOVA in factorial arrangement (2x2x3, in Exp. 1 and 2x2x2, in Exp. 2) with repeated measures in time (except for morphometry and immunolocation) and Tukey test, at 5% level of significance. In Exp. 1, animals evaluated in D4 showed numerical reduction of P4 levels, luteal dimensions and vascularization. Animals evaluated at D11 showed reduction for all parameters evaluated over the experimental moments. The use of 50% or 100% of the luteolytic dose caused a similar reduction in the evaluated variables compared to the negative control. In Exp. 2, the number of caspase-3 immunostained small luteal cells was similar between treatments, and large when administered on D11. Animals treated with 50% of the dose presented larger number of large luteal cells compared to those treated with 100% of the dose. For the area of large luteal cells, treatments administered on D11 influenced this variable similarly, while at D4 the smallest area was detected for animals treated with SC100%. Animals treated with SC and with 100% of the dose on D4 showed larger area of small luteal cells. Animals treated with DT50% had smaller area of small luteal cells. Administration of treatments on D4 and D11 caused a reduction in P4 levels. The main difference observed after administration of SC and DT occurred in the effect exerted by the actives on the large and small luteal cells. Luteal dimensions, CL vascularization and serum P4 levels were similar after administration of the luteolytics agents. Administration of luteolytics on D4 was suggestive of partial luteolysis. The administration on D11 was efficient in inducing complete luteolysis. The study also demonstrated the luteolytic ability to use 50% of the dose of SC and DT when administered in D11.
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Palavras-chave
Reprodução, Corpo lúteo, Luteólise, Reproduction, Corpus luteum, Luteolysis