Função luteal e hipoluteoidismo em cadelas / Función lútea y hipoluteismo en perras / Luteal function and hypoluteoidism in dogs

O controle da função luteal é realizado por um balanço de fatores luteotróficos e luteolíticos, e nenhuma luteolisina de origem uterina está envolvida na regulação do corpo lúteo cíclico canino. Todavia, ao final da gestação, um pico de PGFM reflete a síntese e secreção de PGF2α envolvida na luteólise pré-parto. Em cadelas, a prolactina e o LH, mas também a PGE2, P4 e E2, e possivelmente citocinas e fatores de crescimento agem como fatores autócrinos e parácrinos para regular a função luteal. O hipoluteoidismo é definido como uma diminuição precoce da secreção de progesterona, com concentração insuficiente para a manutenção da gestação, causando perdas gestacionais. Entretanto, o valor de corte da concentração de progesterona para o diagnóstico ainda é controverso. A suplementação exógena com progestágenos é eficaz em manter a gestação, mas nas fases iniciais da gestação pode causar efeitos teratogênicos nos fetos.(AU)

El control de la función lútea se lleva a cabo por un equilibrio de factores luteotróficos y luteolíticos, y ninguna luteolisina de origen uterino está involucrada en la regulación del cuerpo lúteo cíclico canino. Sin embargo, al final del embarazo, un pico de PGFM refleja la síntesis y secreción de PGF2α involucrada en la luteólisis anteparto. En las perras, la prolactina y la LH, pero también la relaxina, PGE2, la P4 y la E2, y posiblemente citoquinas y factores de crecimiento, actúan como factores autocrinos y paracrinos para regular la función lútea. El hipoluteismo se define como una disminución precoz de la secreción de progesterona, con una concentración insuficiente para el mantenimiento del embarazo, provocando pérdidas gestacionales. Sin embargo, el valor de corte de la concentración de progesterona para el diagnóstico sigue siendo controvertido. La suplementación exógena con progestágenos es eficaz para mantener el embarazo, pero puede causar efectos teratogénicos en los fetos.(AU)

Técnica de inseminação artificial por tração cervical e função luteal em ovelhas Santa Inês após estro sincronizado com cloprostenol ou progestágeno-eCG / Technique of artificial ins emination by cervical traction and luteal function in Santa Inês ewes after synchronized estrus with cloprostenol or progestagen-eCG

Avaliou-se a influência do protocolo de sincronização de estro na execução da técnica de inseminação artificial por tração cervical (ITC) e subsequente perfil sérico de progesterona em ovelhas Santa Inês. Um grupo foi submetido a duas aplicações de cloprostenol com sete dias de intervalo (PGF2α, n=43), outro grupo foi sincronizado com MAP-eCG (P4-eCG, n=40) e ovelhas ao estro natural (EN, n=10) formaram grupo controle. Com as ovelhas contidas em estação, foi realizada a técnica ITC utilizando um aplicador metálico e mandril. Foram avaliadas a profundidade de penetração e intensidade de reação da ovelha ao manejo da técnica. Dosagens de estradiol e progesterona foram feitas antes e depois da ITC/estro natural, respectivamente. Os níveis de estradiol foram superiores com P4-eCG vs PGF2α (P < 0,05), mas não houve influência do protocolo na execução da técnica. Ocorreram 83,5% de deposição intrauterina do sêmen, o tempo médio foi de 32 segundos e 90,7% das ovelhas apresentaram reação fraca ou moderada durante o manejo. Os níveis de progesterona foram semelhantes entre ITC e estro natural. Independente do protocolo hormonal, a técnica ITC em ovelhas Santa Inês mantidas em estação mostrou-se viável no tempo de penetração da cérvice e deposição intrauterina do sêmen, não comprometendo a função luteal subsequente.(AU)

The influence of estrus synchronization protocol was evaluated on the artificial insemination technique by cervical traction (ICT) and subsequent progesterone serum profile in Santa Inês ewes. One group was submitted to two applications of cloprostenol seven days apart (PGF2α, n=43), another group was synchronized with MAP-eCG (P4-eCG, n=40) and ewes at natural estrus (NE, n=10) formed a control group. With the ewe contained in the stand position, the ICT technique was performed using a metal applicator and mandrel. Depth of penetration and reaction intensity of the ewe to the handling of the technique were evaluated. Dosages of estradiol and progesterone were performed before and after ICT / natural estrus, respectively. Estradiol levels were higher with P4-eCG vs PGF2α(AU)

Técnica de inseminação artificial por tração cervical e função luteal em ovelhas Santa Inês após estro sincronizado com cloprostenol ou progestágeno-eCG / Technique of artificial ins emination by cervical traction and luteal function in Santa Inês ewes after synchronized estrus with cloprostenol or progestagen-eCG

Avaliou-se a influência do protocolo de sincronização de estro na execução da técnica de inseminação artificial por tração cervical (ITC) e subsequente perfil sérico de progesterona em ovelhas Santa Inês. Um grupo foi submetido a duas aplicações de cloprostenol com sete dias de intervalo (PGF2α, n=43), outro grupo foi sincronizado com MAP-eCG (P4-eCG, n=40) e ovelhas ao estro natural (EN, n=10) formaram grupo controle. Com as ovelhas contidas em estação, foi realizada a técnica ITC utilizando um aplicador metálico e mandril. Foram avaliadas a profundidade de penetração e intensidade de reação da ovelha ao manejo da técnica. Dosagens de estradiol e progesterona foram feitas antes e depois da ITC/estro natural, respectivamente. Os níveis de estradiol foram superiores com P4-eCG vs PGF2α (P < 0,05), mas não houve influência do protocolo na execução da técnica. Ocorreram 83,5% de deposição intrauterina do sêmen, o tempo médio foi de 32 segundos e 90,7% das ovelhas apresentaram reação fraca ou moderada durante o manejo. Os níveis de progesterona foram semelhantes entre ITC e estro natural. Independente do protocolo hormonal, a técnica ITC em ovelhas Santa Inês mantidas em estação mostrou-se viável no tempo de penetração da cérvice e deposição intrauterina do sêmen, não comprometendo a função luteal subsequente.

The influence of estrus synchronization protocol was evaluated on the artificial insemination technique by cervical traction (ICT) and subsequent progesterone serum profile in Santa Inês ewes. One group was submitted to two applications of cloprostenol seven days apart (PGF2α, n=43), another group was synchronized with MAP-eCG (P4-eCG, n=40) and ewes at natural estrus (NE, n=10) formed a control group. With the ewe contained in the stand position, the ICT technique was performed using a metal applicator and mandrel. Depth of penetration and reaction intensity of the ewe to the handling of the technique were evaluated. Dosages of estradiol and progesterone were performed before and after ICT / natural estrus, respectively. Estradiol levels were higher with P4-eCG vs PGF2α

Pregnancy rates and luteal phase characteristics of bovine embryo recipients treated with flunixin meglumine / Taxas de prenhez e características da fase lútea de receptoras de embriões tratadas com flunixina meglumina em bovinos

The aim of this study was to evaluate the effects of flunixin meglumine administration on pregnancy rates and luteal phase characteristics in bovine embryo recipients at the moment of embryo transfer. In experiment 1, in vitro produced embryos were transferred to 184 females divided as control and treated group (recipients treated with 1.1mg/kg flunixin meglumine). In experiment 2, 22 females were divided as control group; group 2 (animals submitted to a reproductive tract manipulation similar to an embryo transfer on the 7th day after estrous); and group 3 (females submitted to a manipulation and treatment with 1.1mg/kg flunixin meglumine). In experiment 1 no difference was observed between control and treated groups (40.2% and 44.6%, respectively) for pregnancy rates. In experiment 2 no difference was observed on the length of luteal phase between groups, however, animals in group 2 presented lower plasma progesterone concentrations than the control group and group 3. Therefore, we concluded that although the administration of flunixin meglumine at the moment of embryo transfer inhibited the reduction plasma progesterone concentrations, it was not effective in increasing pregnancy rates of bovine recipients.(AU)

O objetivo deste estudo foi avaliar os efeitos da administração de flunixina meglumina sobre as taxas de prenhez e características da fase lútea da receptora no momento da transferência de embriões em bovinos. No experimento 1, embriões produzidos in vitro foram transferidos para 184 fêmeas, divididas em grupos controle e tratado (tratados com 1,1mg/kg de flunixina meglumina). No experimento 2, 22 fêmeas foram divididas em grupo controle (n=7); grupo 2 (n=8; animais submetidos à manipulação do trato reprodutivo semelhante à transferência de embriões no sétimo dia pós-cio); e grupo 3 (n=7; fêmeas submetidas à manipulação e ao tratamento com 1,1mg/kg de flunixina meglumina). No experimento 1, não foi observada diferença nos grupos controle e tratado (40,2% e 44,6%, respectivamente) para as taxas de prenhez. No experimento 2, não houve diferença na extensão da fase lútea entre os grupos, entretanto os animais do grupo 2 apresentaram concentrações plasmáticas de progesterona mais baixas que o grupo controle e o grupo 3. Portanto, conclui-se que a administração de flunixina meglumina no momento da transferência de embriões inibiu a redução das concentrações plasmáticas de progesterona, no entanto não foi eficaz para aumentar as taxas de prenhez de receptoras em bovinos.(AU)

Pregnancy rates and luteal phase characteristics of bovine embryo recipients treated with flunixin meglumine / Taxas de prenhez e características da fase lútea de receptoras de embriões tratadas com flunixina meglumina em bovinos

The aim of this study was to evaluate the effects of flunixin meglumine administration on pregnancy rates and luteal phase characteristics in bovine embryo recipients at the moment of embryo transfer. In experiment 1, in vitro produced embryos were transferred to 184 females divided as control and treated group (recipients treated with 1.1mg/kg flunixin meglumine). In experiment 2, 22 females were divided as control group; group 2 (animals submitted to a reproductive tract manipulation similar to an embryo transfer on the 7th day after estrous); and group 3 (females submitted to a manipulation and treatment with 1.1mg/kg flunixin meglumine). In experiment 1 no difference was observed between control and treated groups (40.2% and 44.6%, respectively) for pregnancy rates. In experiment 2 no difference was observed on the length of luteal phase between groups, however, animals in group 2 presented lower plasma progesterone concentrations than the control group and group 3. Therefore, we concluded that although the administration of flunixin meglumine at the moment of embryo transfer inhibited the reduction plasma progesterone concentrations, it was not effective in increasing pregnancy rates of bovine recipients.(AU)

O objetivo deste estudo foi avaliar os efeitos da administração de flunixina meglumina sobre as taxas de prenhez e características da fase lútea da receptora no momento da transferência de embriões em bovinos. No experimento 1, embriões produzidos in vitro foram transferidos para 184 fêmeas, divididas em grupos controle e tratado (tratados com 1,1mg/kg de flunixina meglumina). No experimento 2, 22 fêmeas foram divididas em grupo controle (n=7); grupo 2 (n=8; animais submetidos à manipulação do trato reprodutivo semelhante à transferência de embriões no sétimo dia pós-cio); e grupo 3 (n=7; fêmeas submetidas à manipulação e ao tratamento com 1,1mg/kg de flunixina meglumina). No experimento 1, não foi observada diferença nos grupos controle e tratado (40,2% e 44,6%, respectivamente) para as taxas de prenhez. No experimento 2, não houve diferença na extensão da fase lútea entre os grupos, entretanto os animais do grupo 2 apresentaram concentrações plasmáticas de progesterona mais baixas que o grupo controle e o grupo 3. Portanto, conclui-se que a administração de flunixina meglumina no momento da transferência de embriões inibiu a redução das concentrações plasmáticas de progesterona, no entanto não foi eficaz para aumentar as taxas de prenhez de receptoras em bovinos.(AU)

Relação do proteinograma sérico e as fases folicular e luteal do ciclo estral em éguas / Relation of the serum proteins and the follicular and luteal phasesof the estrous cycle in mares

O objetivo deste estudo foi obter o perfil eletroforético das proteínas séricas em éguas cíclicas e verificar as diferenças entre as fases folicular e luteal do ciclo estral nesta espécie. Foram utilizadas 18 éguas, totalizando 36 amostras de soro, sendo duas de cada égua. As amostras foram colhidas no estro e no diestro. As proteínas séricas totais foram obtidas pelo método do Biureto, a partir da utilização de Kits comerciais (LABTEST®) e, as diferentes subfrações proteicas, por eletroforese em gel de poliacrilamida (SDS-PAGE). O eletroforetograma das proteínas séricas colocou em evidência a presença de 17 a 25 frações proteicas, cujos pesos moleculares variaram de 22 a 254 kDa. Identificaram-se duas proteínas ainda não nomeadas oficialmente, de massas moleculares (MM) 23 kDa e 144 kDa. Os valores médios ± SEM obtidos para cada variável no estro e no diestro, respectivamente, foram: proteínas totais (g/dL) 7,11 ± 0,07 e 7,36 ± 0,07; albumina (mg/dL) 4790,83 ± 69,10 e 5027,19 ± 69,10; α1 glicoproteína ácida (mg/dL) 4,90 ± 0,31 e 4,93 ± 0,31; ceruloplasmina (mg/dL) 15,28 ± 1,31 e 10,65 ± 1,31; haptoglobina (mg/dL) 22,70 ± 1,16 e 27,06 ± 1,16; transferrina (mg/dL) 329,00 ± 9,78 e 350,16 ± 9,78; IgA (mg/dL) 119,91 ± 6,30 e 107,03 ± 6,30; IgG (mg/dL) 1525,07 ± 40,18 e 1517,25 ± 40,18; MM 23 (mg/dL) 204,44 ± 8,61 e 219,79 ± 8,61; MM 144 (mg/dL) 22,13 ± 0,55 e 21,49 ± 0,55. Não houve diferença significativa das proteínas totais e suas frações do estro para o diestro. Conclui-se que as modificações hormonais durante as fases do ciclo estral da égua não interferem no proteinograma sérico.(AU)

This study aimed to obtain the electrophoretic profile of serum proteins in cyclic mares and to verify the differences between the follicular and luteal phases of the estrous cycle in this species. Eighteen mares were used, totaling 36 serum samples, two of each mare. Samples were collected both in estrus and in diestrus. Total serum proteins were obtained by the Biureto method, by using commercial kits (LABTEST®), while the different protein subfractions by polyacrylamide gel electrophoresis (SDS-PAGE). The electroforetogram of serum proteins evidenced the presence of 17 to 25 protein fractions, whose molecular weights ranged from 22 to 254 kDa. Two proteins that were not yet officially named were identified, of molecular weights (MW) of 23 kDa and 144 kDa. The mean values (± SEM) obtained for each variable in estrus and diestrus were, respectively: total proteins (g/dL) 7.11 ± 0.07 and 7.36 ± 0.07; albumin (mg/dL) 4790.83 ± 69.10 and 5027.19 ± 69.10; α1 acid glycoprotein (mg/dL) 4.90 ± 0.31 and 4.93 ± 0.31; ceruloplasmine (mg/dL) 15.28 ± 1.31 and 10.65 ± 1.31; haptoglobine (mg/dL) 22.70 ± 1.16 and 27.06 ± 1.16; transferrin (mg/ dL) 329.00 ± 9.78 and 350.16 ± 9.78; IgA (mg/dL) 119.91 ± 6.30 and 107.03 ± 6.30; IgG (mg/dL) 1525.07 ± 40.18 and 1517.25 ± 40.18; MW 23 (mg/dL) 204.44 ± 8.61 and 219.79 ± 8.61; MW 144 (mg/dL) 22.13 ± 0.55 and 21.49 ± 0.55. No significant difference was verified in total proteins and its fractions in estrus and diestrus. The hormonal changes during the specific stages of the estrous cycle of the mare do not interfere with the serum proteinogram.(AU)

Relação do proteinograma sérico e as fases folicular e luteal do ciclo estral em éguas / Relation of the serum proteins and the follicular and luteal phasesof the estrous cycle in mares

O objetivo deste estudo foi obter o perfil eletroforético das proteínas séricas em éguas cíclicas e verificar as diferenças entre as fases folicular e luteal do ciclo estral nesta espécie. Foram utilizadas 18 éguas, totalizando 36 amostras de soro, sendo duas de cada égua. As amostras foram colhidas no estro e no diestro. As proteínas séricas totais foram obtidas pelo método do Biureto, a partir da utilização de Kits comerciais (LABTEST®) e, as diferentes subfrações proteicas, por eletroforese em gel de poliacrilamida (SDS-PAGE). O eletroforetograma das proteínas séricas colocou em evidência a presença de 17 a 25 frações proteicas, cujos pesos moleculares variaram de 22 a 254 kDa. Identificaram-se duas proteínas ainda não nomeadas oficialmente, de massas moleculares (MM) 23 kDa e 144 kDa. Os valores médios ± SEM obtidos para cada variável no estro e no diestro, respectivamente, foram: proteínas totais (g/dL) 7,11 ± 0,07 e 7,36 ± 0,07; albumina (mg/dL) 4790,83 ± 69,10 e 5027,19 ± 69,10; α1 glicoproteína ácida (mg/dL) 4,90 ± 0,31 e 4,93 ± 0,31; ceruloplasmina (mg/dL) 15,28 ± 1,31 e 10,65 ± 1,31; haptoglobina (mg/dL) 22,70 ± 1,16 e 27,06 ± 1,16; transferrina (mg/dL) 329,00 ± 9,78 e 350,16 ± 9,78; IgA (mg/dL) 119,91 ± 6,30 e 107,03 ± 6,30; IgG (mg/dL) 1525,07 ± 40,18 e 1517,25 ± 40,18; MM 23 (mg/dL) 204,44 ± 8,61 e 219,79 ± 8,61; MM 144 (mg/dL) 22,13 ± 0,55 e 21,49 ± 0,55. Não houve diferença significativa das proteínas totais e suas frações do estro para o diestro. Conclui-se que as modificações hormonais durante as fases do ciclo estral da égua não interferem no proteinograma sérico.

This study aimed to obtain the electrophoretic profile of serum proteins in cyclic mares and to verify the differences between the follicular and luteal phases of the estrous cycle in this species. Eighteen mares were used, totaling 36 serum samples, two of each mare. Samples were collected both in estrus and in diestrus. Total serum proteins were obtained by the Biureto method, by using commercial kits (LABTEST®), while the different protein subfractions by polyacrylamide gel electrophoresis (SDS-PAGE). The electroforetogram of serum proteins evidenced the presence of 17 to 25 protein fractions, whose molecular weights ranged from 22 to 254 kDa. Two proteins that were not yet officially named were identified, of molecular weights (MW) of 23 kDa and 144 kDa. The mean values (± SEM) obtained for each variable in estrus and diestrus were, respectively: total proteins (g/dL) 7.11 ± 0.07 and 7.36 ± 0.07; albumin (mg/dL) 4790.83 ± 69.10 and 5027.19 ± 69.10; α1 acid glycoprotein (mg/dL) 4.90 ± 0.31 and 4.93 ± 0.31; ceruloplasmine (mg/dL) 15.28 ± 1.31 and 10.65 ± 1.31; haptoglobine (mg/dL) 22.70 ± 1.16 and 27.06 ± 1.16; transferrin (mg/ dL) 329.00 ± 9.78 and 350.16 ± 9.78; IgA (mg/dL) 119.91 ± 6.30 and 107.03 ± 6.30; IgG (mg/dL) 1525.07 ± 40.18 and 1517.25 ± 40.18; MW 23 (mg/dL) 204.44 ± 8.61 and 219.79 ± 8.61; MW 144 (mg/dL) 22.13 ± 0.55 and 21.49 ± 0.55. No significant difference was verified in total proteins and its fractions in estrus and diestrus. The hormonal changes during the specific stages of the estrous cycle of the mare do not interfere with the serum proteinogram.

Efeito da técnica de coleta e do estágio do ciclo estral na recuperação de oócitos de boa qualidade em felinos e caninos domésticos / The effect of recovery technique and stage of estrous cycle on the recovery of good quality oocytes in domestic felines and canines

A obtenção de oócitos de boa qualidade é essencial para o sucesso de diversas biotécnicas reprodutivas. Objetivou-se determinar o efeito de duas técnicas na recuperação de oócitos de boa qualidade em gatas e cadelas em diferentes estágios reprodutivos. Foram utilizados 43 pares de ovários de gata e 35 de cadela após realização da ovariosalpingohisterectomia eletiva. A fase do ciclo estral foi classificada em inativa, folicular ou luteal. Os ovários da fase folicular foram divididos em três grupos: PUN) punção dos folículos com agulha; PUN+FAT) fatiamento do mesmo ovário já puncionado; e FAT) fatiamento do segundo ovário. Os ovários das fêmeas em fase luteal e inativa foram submetidos ao FAT. Foram obtidos no total 974 oócitos (~23/animal) nas fêmeas felinas e 940 (~27/animal) nas caninas. O fatiamento recuperou número superior (P<0,05) de oócitos. Não houve diferença (P>0,05) entre as técnicas de coleta na qualidade de estruturas recuperadas. A quantidade de oócitos recuperados em cada fase foi similar (P>0,05). Contudo, a fase inativa foi superior à luteal (P<0,05) e semelhante à folicular na quantidade de oócitos de boa qualidade em gatas e não houve diferença em cadelas. Conclui-se que o fatiamento recupera maior quantidade de oócitos, não influenciando em sua qualidade. As fases inativa e folicular recuperam maior quantidade de oócitos de boa qualidade em gatas e não afetam a recuperação em cadelas. Portanto, para otimizar o uso das biotecnologias, deve-se levar em consideração o estágio do ciclo estral em fêmeas felinas e a técnica de coleta utilizada na recuperação de oócitos.

The recovery of good quality oocytes is essential for the success of various reproductive biotechniques. The aim of this study was to determine the effect of two techniques on the recovery of good quality oocytes in queens and bitches at different reproductive stages. A total of 43 pairs of ovaries of queens and 35 of bitches after elective ovariosalpingohisterectomy were performed. The estrous cycle phase was classified as inactive, follicular or luteal. The ovaries of the follicular phase were allocated into three groups: PUN) puncture of the follicles with a needle; PUN + SLI) slicing of the same ovary already punctured; and SLI) slicing of the second ovary. The ovaries of luteal and inactive females were submitted to SLI. A total of 974 oocytes (~23/animal) were obtained in feline females and 940 (~27/animal) in canines females. The SLI technique recovered superior number (P<0.05) of oocytes. There was no difference (P>0.05) between the collection techniques in the quality of recovered structures. The number of oocytes recovered in each phase was similar (P>0.05). However, the inactive phase was higher than luteal (P<0.05) and similar to the follicular phase in the quantity of good-quality oocytes in queens and there was no difference in bitches. In conclusion, it is preferable to perform the slicing technique to recover more oocytes in both species. Moreover, in queens it is possible to obtain good quality oocytes in the inactive phase and in bitches the estrous cycle phase does not influence the quality.

Relação do proteinograma sérico e as fases folicular e luteal do ciclo estral em éguas / Relation of the serum proteins and the follicular and luteal phases of the estrous cycle in mares

O objetivo deste estudo foi obter o perfil eletroforético das proteínas séricas em éguas cíclicas e verificar as diferenças entre as fases folicular e luteal do ciclo estral nesta espécie. Foram utilizadas 18 éguas, totalizando 36 amostras de soro, sendo duas de cada égua. As amostras foram colhidas no estro e no diestro. As proteínas séricas totais foram obtidas pelo método do Biureto, a partir da utilização de Kits comerciais (LABTEST) e, as diferentes subfrações proteicas, por eletroforese em gel de poliacrilamida (SDS-PAGE). O eletroforetograma das proteínas séricas colocou em evidência a presença de 17 a 25 frações proteicas, cujos pesos moleculares variaram de 22 a 254 kDa. Identificaram-se duas proteínas ainda não nomeadas oficialmente, de massas moleculares (MM) 23 kDa e 144 kDa. Os valores médios ± SEM obtidos para cada variável no estro e no diestro, respectivamente, foram: proteínas totais (g/dL) 7,11 ± 0,07 e 7,36 ± 0,07; albumina (mg/dL) 4790,83 ± 69,10 e 5027,19 ± 69,10; α1 glicoproteína ácida (mg/dL) 4,90 ± 0,31 e 4,93 ± 0,31; ceruloplasmina (mg/dL) 15,28 ± 1,31 e 10,65 ± 1,31; haptoglobina (mg/dL) 22,70 ± 1,16 e 27,06 ± 1,16; transferrina (mg/dL) 329,00 ± 9,78 e 350,16 ± 9,78; IgA (mg/dL) 119,91 ± 6,30 e 107,03 ± 6,30; IgG (mg/dL) 1525,07 ± 40,18 e 1517,25 ± 40,18; MM 23 (mg/dL) 204,44 ± 8,61 e 219,79 ± 8,61; MM 144 (mg/dL) 22,13 ± 0,55 e 21,49 ± 0,55. Não houve diferença significativa das proteínas totais e suas frações do estro para o diestro. Conclui-se que as modificações hormonais durante as fases do ciclo estral da égua não interferem no proteinograma sérico.

This study aimed to obtain the electrophoretic profile of serum proteins in cyclic mares and to verify the differences between the follicular and luteal phases of the estrous cycle in this species. Eighteen mares were used, totaling 36 serum samples, two of each mare. Samples were collected both in estrus and in diestrus. Total serum proteins were obtained by the Biureto method, by using commercial kits (LABTEST), while the different protein subfractions by polyacrylamide gel electrophoresis (SDS-PAGE). The electroforetogram of serum proteins evidenced the presence of 17 to 25 protein fractions, whose molecular weights ranged from 22 to 254 kDa. Two proteins that were not yet officially named were identified, of molecular weights (MW) of 23 kDa and 144 kDa. The mean values (± SEM) obtained for each variable in estrus and diestrus were, respectively: total proteins (g/dL) 7.11 ± 0.07 and 7.36 ± 0.07; albumin (mg/dL) 4790.83 ± 69.10 and 5027.19 ± 69.10; α1 acid glycoprotein (mg/dL) 4.90 ± 0.31 and 4.93 ± 0.31; ceruloplasmine (mg/dL) 15.28 ± 1.31 and 10.65 ± 1.31; haptoglobine (mg/dL) 22.70 ± 1.16 and 27.06 ± 1.16; transferrin (mg/dL) 329.00 ± 9.78 and 350.16 ± 9.78; IgA (mg/dL) 119.91 ± 6.30 and 107.03 ± 6.30; IgG (mg/dL) 1525.07 ± 40.18 and 1517.25 ± 40.18; MW 23 (mg/dL) 204.44 ± 8.61 and 219.79 ± 8.61; MW 144 (mg/dL) 22.13 ± 0.55 and 21.49 ± 0.55. No significant difference was verified in total proteins and its fractions in estrus and diestrus. The hormonal changes during the specific stages of the estrous cycle of the mare do not interfere with the serum proteinogram.

Effect of aflatoxin B1 on blood serum oestradiol-17β and progesterone concentrations during the luteal phase and the synchronized oestrus of goats

The effect of prolonged aflatoxin B1 (AFB1) administration on blood serum oestradiol-17β and progesterone concentrations in goats during the luteal phase and the synchronized oestrus was investigated. Thirty-six Greek indigenous primiparous goats were used, during the oestrus period; 12 goats received, per os, 50 μg (treated group T50) and 12 goats received 100 μg (treated group T100) AFB1/day/head, respectively, for approximately 1.5 month, while 12 goats served as controls (C). On day 36 of the experiment, each goat was injected, i.m, 0.5 ml prostaglandin F2α (PGF2α). Blood samples were collected from each goat twice a week, before PGF2α injection, as well as every 4 hours from the onset to the end of the synchronized oestrus. Oestradiol-17β and progesterone concentrations in blood serum were determined using radioimmunoassay. During the whole luteal(s) phase(s), linear regression analysis revealed a significant negative dependence (P 0.05). In conclusion, prolonged AFB1 administration at doses of 100 or even of 50 μg/day/head changes the hormonal pattern in blood during the luteal phase and the synchronized oestrus of goats, being in oestrus period.

Effect of aflatoxin B1 on blood serum oestradiol-17β and progesterone concentrations during the luteal phase and the synchronized oestrus of goats

The effect of prolonged aflatoxin B1 (AFB1) administration on blood serum oestradiol-17β and progesterone concentrations in goats during the luteal phase and the synchronized oestrus was investigated. Thirty-six Greek indigenous primiparous goats were used, during the oestrus period; 12 goats received, per os, 50 μg (treated group T50) and 12 goats received 100 μg (treated group T100) AFB1/day/head, respectively, for approximately 1.5 month, while 12 goats served as controls (C). On day 36 of the experiment, each goat was injected, i.m, 0.5 ml prostaglandin F2α (PGF2α). Blood samples were collected from each goat twice a week, before PGF2α injection, as well as every 4 hours from the onset to the end of the synchronized oestrus. Oestradiol-17β and progesterone concentrations in blood serum were determined using radioimmunoassay. During the whole luteal(s) phase(s), linear regression analysis revealed a significant negative dependence (P < 0.05) of oestradiol-17β and a significant positive dependence (P < 0.05) of progesterone over group (C = 0, T50 = 50, T100 = 100), in a dose dependent manner. During the synchronized oestrus, multiple linear regression analysis revealed a significant negative dependence (P < 0.05) of oestradiol-17β, as well as a significant positive dependence (P < 0.05) of progesterone over group (C = 0, T50 = 50, T100 = 100) and over time (hours, from the onset to the end of the synchronized oestrus). No significant differences were noticed among the three groups, regarding the body weight of the goats from the onset to the end of AFB1 administration, the occurrence or the duration of the synchronized oestrus presented by the goats (P > 0.05). In conclusion, prolonged AFB1 administration at doses of 100 or even of 50 μg/day/head changes the hormonal pattern in blood during the luteal phase and the synchronized oestrus of goats, being in oestrus period.(AU)

Sudden introduction of bucks during the late luteal phase of isolated female goats induces a biphasic change in progesterone concentrations

The aim was to determine the progesterone profile after the introduction of bucks during the advanced luteal phase of does. Fourteen does received vaginal sponges impregnated with 40 mg fluorogestone acetate for 12 days, and a luteolytic dose of a prostaglandin analogue (75 μg of D-cloprostenol) 2 days before sponge removal. Fifteen days after sponge withdrawal one buck was introduced in one of the pens (BE group; n = 6), while the female goats in the other pen remained as controls (CON group; n = 8). The buck was replaced every 24 h, alternating their presence until the end of the experiment. Serum progesterone levels were used to monitor ovarian activity. Progesterone concentration from day 14 to 20 varied with time (P < 0.0001), and there was an interaction between treatment and day (P = 0.02). While progesterone concentration increased from day 15 to day 16 in BE does (P = 0.01), there were no changes in CON does on those days (P = 0.2). On the other hand, progesterone concentrations decreased in BE does from day 18 to day 19 (P = 0.02), without changes in CON does (P = 0.6). Finally, there was a sharp decrease from day 19 to day 20 in both BE (P = 0.0009) and CON (P < 0.0001) does. Overall, our results demonstrated that the introduction of bucks during the late luteal phase of isolated does can induce changes in the progesterone pattern, showing an early increase followed by a pronounced withdrawn.(AU)

Sudden introduction of bucks during the late luteal phase of isolated female goats induces a biphasic change in progesterone concentrations

The aim was to determine the progesterone profile after the introduction of bucks during the advanced luteal phase of does. Fourteen does received vaginal sponges impregnated with 40 mg fluorogestone acetate for 12 days, and a luteolytic dose of a prostaglandin analogue (75 μg of D-cloprostenol) 2 days before sponge removal. Fifteen days after sponge withdrawal one buck was introduced in one of the pens (BE group; n = 6), while the female goats in the other pen remained as controls (CON group; n = 8). The buck was replaced every 24 h, alternating their presence until the end of the experiment. Serum progesterone levels were used to monitor ovarian activity. Progesterone concentration from day 14 to 20 varied with time (P < 0.0001), and there was an interaction between treatment and day (P = 0.02). While progesterone concentration increased from day 15 to day 16 in BE does (P = 0.01), there were no changes in CON does on those days (P = 0.2). On the other hand, progesterone concentrations decreased in BE does from day 18 to day 19 (P = 0.02), without changes in CON does (P = 0.6). Finally, there was a sharp decrease from day 19 to day 20 in both BE (P = 0.0009) and CON (P < 0.0001) does. Overall, our results demonstrated that the introduction of bucks during the late luteal phase of isolated does can induce changes in the progesterone pattern, showing an early increase followed by a pronounced withdrawn.

Expression of epidermal growth factor (EGF) and its receptor in bovine endometrium throughout the luteal phase: effects of EGF on prostaglandin production in endometrial cells

Epidermal growth factor (EGF) is produced in bovine endometrium throughout the estrous cycle. However, little is known about the expression of the EGF receptor (EGFR) and the roles of EGF in bovine endometrium. To clarify whether EGF is involved in local regulation of bovine endometrial function, first we determined the EGF protein and the expression of EGFR mRNA in endometrial tissues throughout the luteal stages. EGF protein concentration was higher(P < 0.05) in the mid (days 8-12) luteal stage than in the other luteal stages. EGFR mRNA expression was higher (P < 0.05) in the mid and late (days 15-17) luteal stages than in the other luteal stages. To investigate the protein concentrations of EGF and EGFR mRNA expression in cultured bovine endometrial cells, epithelial and stromal cells were isolated between day 0 and day 4 post-ovulation from 22 uteri. Both EGF protein concentration and EGFR mRNA expression were higher (P < 0.05) in epithelial cells than in stromal cells. Then, to examine the possible role of EGF in the regulation of prostaglandin F2α (PGF2α) and prostaglandin E2 (PGE2), cultured endometrial epithelial and stromal cells were exposed to EGF (0, 1, 10 and 100 nm) for 24 h. In epithelial cells, EGF (10 and/or 100 nm) increased (P < 0.05) PGF2α and PGE2 secretion, but in stromal cells EGF (100 nm) increased (P < 0.05) PGF2α, but not PGE2 secretion. These results indicate that 1) the highest amount of EGF is produced by bovine endometrium at the mid-luteal stage, 2) endometrial EGFR mRNA expressions are higher at mid and late-luteal stages than other stages, 3) EGF is expressed mainly by uterine epithelial cells and 4) EGF has the ability to increase PGE2 and PGF2α production in both epithelial and stromal cells and therefore may play a role in local regulation of uterine function.

Expression of epidermal growth factor (EGF) and its receptor in bovine endometrium throughout the luteal phase: effects of EGF on prostaglandin production in endometrial cells

Epidermal growth factor (EGF) is produced in bovine endometrium throughout the estrous cycle. However, little is known about the expression of the EGF receptor (EGFR) and the roles of EGF in bovine endometrium. To clarify whether EGF is involved in local regulation of bovine endometrial function, first we determined the EGF protein and the expression of EGFR mRNA in endometrial tissues throughout the luteal stages. EGF protein concentration was higher(P < 0.05) in the mid (days 8-12) luteal stage than in the other luteal stages. EGFR mRNA expression was higher (P < 0.05) in the mid and late (days 15-17) luteal stages than in the other luteal stages. To investigate the protein concentrations of EGF and EGFR mRNA expression in cultured bovine endometrial cells, epithelial and stromal cells were isolated between day 0 and day 4 post-ovulation from 22 uteri. Both EGF protein concentration and EGFR mRNA expression were higher (P < 0.05) in epithelial cells than in stromal cells. Then, to examine the possible role of EGF in the regulation of prostaglandin F2α (PGF2α) and prostaglandin E2 (PGE2), cultured endometrial epithelial and stromal cells were exposed to EGF (0, 1, 10 and 100 nm) for 24 h. In epithelial cells, EGF (10 and/or 100 nm) increased (P < 0.05) PGF2α and PGE2 secretion, but in stromal cells EGF (100 nm) increased (P < 0.05) PGF2α, but not PGE2 secretion. These results indicate that 1) the highest amount of EGF is produced by bovine endometrium at the mid-luteal stage, 2) endometrial EGFR mRNA expressions are higher at mid and late-luteal stages than other stages, 3) EGF is expressed mainly by uterine epithelial cells and 4) EGF has the ability to increase PGE2 and PGF2α production in both epithelial and stromal cells and therefore may play a role in local regulation of uterine function.(AU)

Morfologia da cérvice de ovelhas santa inês adultas nas fases luteínica e folicular / Morphology of the cervix of Santa Ines adult sheep in luteal and follicular phases

The ovine cervix is irregularly shaped, making it a challenge to pass through it during artificial insemination. Thus, the aim of this study was to describe the morphological characteristics of the cervix of Santa Ines breed, comparing the phases of the estrous cycle. A total of 112 uteri were collected from non-pregnant ewes and silicone was injected into the lumen of the cervix in order to obtain a cast of the cervical canal. Mean length of the cervix was 41.33 ± 16.38 mm and the most frequent cervical ostium type found was the duck-beak (46%). Two rings were the minimum and seven were the maximum found in the cervix, with means of 4.70 ± 1.05 rings. Morphometric data from each cervical ring indicates that the inner circumference tapers in the middle portion and then becomes to enlarge again. No significant difference (p> 0.05) was found when comparing the luteal and follicular phases, or the types of cervix regarding to the values of the diameter of the folds, height, inside circumference, midpoint between the folds and distance from the opening to the folds. Under the studied conditions, we concluded that the development of semen applicator should take into account the morphometric limits found, although the morphology and morphometry of the ovine cervix is quite varied, with no standard patterns for the species, even when comparing the luteal and follicular phases.

A cérvice ovina tem formato irregular, tornando um desafio transpassá-la durante a inseminação artificial. Logo, este trabalho teve por objetivo descrever as características morfológicas da cérvice de ovelhas da raça Santa Inês, comparando-se as fases do ciclo estral. Foram coletados 112 úteros de ovelhas adultas não gestantes e silicone foi injetado no lúmen da cérvice obtendo-se um molde do canal cervical.  O comprimento médio foi de 41,33± 16,38 mm e o tipo de óstio cervical mais frequente foi o bico-de-pato (46%). O número mínimo de anéis encontrados nas cérvices foi de dois e o máximo de sete, com média de 4,70 ± 1,05 anéis. A morfometria de cada anel cervical indica que a circunferência interna se afunila na porção média e em seguida torna a aumentar. Não houve diferença significativa (p>0,05) quando se compararam as fases luteínica e folicular e entre os tipos de cérvice quanto ao diâmetro das dobras, altura das dobras, circunferência interna, ponto médio entre as dobras e distância do orifício para as dobras. Nas condições estudadas, concluiu-se que o desenvolvimento de um aplicador de sêmen deve levar em consideração os limites morfométricos encontrados, embora a morfologia e morfometria da cérvice da espécie ovina seja bastante variada, não havendo uma forma padrão para a espécie, inclusive quando são comparadas as fases luteínica e folicular.

The seasonal and ovarian status effects on in vitro production of domestic cat embryos between Equator and Tropic of Capricorn / Efeitos da sazonalidade e da condição ovariana sobre a produção in vitro de embriões de gatos domésticos em uma região entre o Equador e o Trópico de Capricórnio

From the Tropic of Capricorn to Equator, the seasonality of domestic cat is known to be absent, i.e., these animals are considered non-seasonal breeders at these regions. We hypothesized that this particularity might have some influence on in vitro embryo production. The aim of this experiment was to determine the percentage of cleavage and morulae and blastocyst formation produced from oocytes recovered from queen ovaries of three distinct status - follicular, luteal or inactive - during two different reproductive seasons experienced by cats in southeast of Brazil (22°53'09" S and 48°26'42" W) - non breeding season (NBS), comprehending January to March; and breeding season (BS), August to October. Thirty queens were neutered. [...] During NBS, from a total of 272 (inactive), 162 (luteal) and 134 (follicular) fertilized oocytes, the percentage of cleaved zygotes, morulae and blastocysts derived from inactive ovaries were 24.63, 16.54 and 8.09 respectively; for those derived from luteal ovaries, the percentage was 21.6, 12.96 and 8.64, and for those from follicular ovaries, they were 24.62, 16.41 and 8.21. Considering BS, from a total of 102 (inactive), 198 (luteal) and 86 (follicular) fertilized oocytes, the relative frequency (%) of cleaved zygotes, morulae and blastocysts derived from inactive ovaries were 64.7, 41.17 and 23.53 respectively; for those derived from luteal ovaries, the percentage was 64.14, 40.41 and 23.73, and for those from follicular ovaries, they were 63.95, 39.54 and 24.41. The results of this experiment demonstrate that no statistically significant difference (P<0.05) was verified in the frequency of cleaved embryos and morulae and blastocyst formation when comparing the three ovarian conditions in the same season. However the breeding season presented better results considering cleavage and morulae and blastocyst formation.(AU)

Do Trópico de Capricórnio ao Equador, sabe-se que a sazonalidade no gato domestico é ausente, i.e., estes animais são considerados reprodutores não sazonais nestas regiões. [...] O objetivo deste experimento foi determinar a porcentagem de clivagem e formação de mórulas e blastocistos produzidos a partir de oócitos recuperados de ovários de gatas em três condições - folicular, lútea ou inativa - durante duas estações reprodutivas pelas quais gatas passam na região sudeste do Brasil (22°53'09" S e 48°26'42" O) - estação não reprodutiva (ENR), que compreende os meses de janeiro a março; e estação reprodutiva (ER), agosto à outubro. Trinta gatas foram castradas. [...] Durante a ENR, de um total de 272 (inativo), 162 (lútea) e 134 (folicular) oócitos fertilizados, a porcentagem de clivagem de zigotos, formação de mórulas e de blastocistos derivados de ovários inativos foi 24,63, 16,54 e 8,09 respectivamente; para aqueles oriundos de ovários na condição lútea, a porcentagem foi de 21,6, 12,96 e 8,64, e para aqueles provenientes de ovários na fase folicular, foi de 24,62, 16,41 e 8,21. Considerando a ER, de um total de 102 (inativo), 198 (lútea) e 86 (folicular) oócitos fertilizados, a frequência relativa (%) de zigotos clivados, mórulas e blastocistos derivados de ovários na condição inativa foi de 64,7, 41,17 e 23,53 respectivamente; para aqueles oriundos de ovários na condição lútea, a porcentagem foi de 64,14, 40,41 e 23,73, e para aqueles provenientes de ovários na fase folicular, foi de 63,95, 39,54 e 24,41. Os resultados deste experimento demonstraram que não houve diferença estatística significante (P < 0.05) na frequência de embriões clivados e na formação de mórulas e blastocistos quando comparadas as três condições ovarianas dentro da mesma estação. Entretanto, a ER apresentou resultados melhores considerando as taxas de clivagem e formação de mórula e de blastocisto se comparada à ENR.(AU)

Morfologia da cérvice de ovelhas santa inês adultas nas fases luteínica e folicular / Morphology of the cervix of Santa Ines adult sheep in luteal and follicular phases

The ovine cervix is irregularly shaped, making it a challenge to pass through it during artificial insemination. Thus, the aim of this study was to describe the morphological characteristics of the cervix of Santa Ines breed, comparing the phases of the estrous cycle. A total of 112 uteri were collected from non-pregnant ewes and silicone was injected into the lumen of the cervix in order to obtain a cast of the cervical canal. Mean length of the cervix was 41.33 ± 16.38 mm and the most frequent cervical ostium type found was the duck-beak (46%). Two rings were the minimum and seven were the maximum found in the cervix, with means of 4.70 ± 1.05 rings. Morphometric data from each cervical ring indicates that the inner circumference tapers in the middle portion and then becomes to enlarge again. No significant difference (p> 0.05) was found when comparing the luteal and follicular phases, or the types of cervix regarding to the values of the diameter of the folds, height, inside circumference, midpoint between the folds and distance from the opening to the folds. Under the studied conditions, we concluded that the development of semen applicator should take into account the morphometric limits found, although the morphology and morphometry of the ovine cervix is quite varied, with no standard patterns for the species, even when comparing the luteal and follicular phases.(AU)

A cérvice ovina tem formato irregular, tornando um desafio transpassá-la durante a inseminação artificial. Logo, este trabalho teve por objetivo descrever as características morfológicas da cérvice de ovelhas da raça Santa Inês, comparando-se as fases do ciclo estral. Foram coletados 112 úteros de ovelhas adultas não gestantes e silicone foi injetado no lúmen da cérvice obtendo-se um molde do canal cervical.  O comprimento médio foi de 41,33± 16,38 mm e o tipo de óstio cervical mais frequente foi o bico-de-pato (46%). O número mínimo de anéis encontrados nas cérvices foi de dois e o máximo de sete, com média de 4,70 ± 1,05 anéis. A morfometria de cada anel cervical indica que a circunferência interna se afunila na porção média e em seguida torna a aumentar. Não houve diferença significativa (p>0,05) quando se compararam as fases luteínica e folicular e entre os tipos de cérvice quanto ao diâmetro das dobras, altura das dobras, circunferência interna, ponto médio entre as dobras e distância do orifício para as dobras. Nas condições estudadas, concluiu-se que o desenvolvimento de um aplicador de sêmen deve levar em consideração os limites morfométricos encontrados, embora a morfologia e morfometria da cérvice da espécie ovina seja bastante variada, não havendo uma forma padrão para a espécie, inclusive quando são comparadas as fases luteínica e folicular.(AU)

Administration of human chorionic gonadotropin to improve luteal function in lactating beef cattle / Administração de gonadotrofina coriônica humana para estimulação da função luteal em vacas de corte lactantes

Background: Pregnancy rate after fixed-time artificial insemination (FTAI) in beef cattle is affected by ovulation rate,luteal function and embryo survival. Cows in early post partum period frequently have low progesterone productionand short luteal phases. Treatments using human chorionic gonadotropin (hCG) after FTAI have been tested in aneffort to increase progesterone concentration, improve embryo development and consequently pregnancy rates. Theobjectives of this work were to evaluate the effects of administration of hCG on day 4 after FTAI on induction ofovulation of the first dominant follicle, corpus luteum (CL) development, progesterone production and pregnancyrate in lactating beef cows.Materials, Methods & Results: Five hundred and sixty nine multiparous Angus suckled beef cows, 45-70 dayspostpartum, were synchronized to FTAI. On day -9, intravaginal implants containing 0,750 g of progesterone wereinserted and 2mg of estradiol benzoate administered, im. Seven days later, cows had their implants removed andwere injected with 150 µg of d-cloprostenol, im, and 1 mg of estradiol cipionate, im. Cows were inseminated 52-56h after implant removal. Four days later, cows were assigned into two groups, hCG (1500 UI of hCG, im, n = 269) orControl (1,5 mL saline, im, n = 300). Blood samples were collected on days 4, 7, 10 and 14 after FTAI for analysisof serum progesterone concentration by radioimmunoassay. Ovarian ultrasonographic exams were done on day 0 todetermine the diameter of ovulatory follicle (OF), on day 4 to measure the diameter of the first dominant follicle and,on day 7, to determine the CL area (cm2) and the number of accesory CL. Pregnancy diagnosis were done on day 30.Pregnancy rates were compared by chi-square test, progesterone concentration and CLs parameters were comparedby student-t test. The administration of hCG resulted in higher serum progesterone concentration, improved CL areaand the frequency of accessory CL...

The role of proestrus on fertility and postovulatory uterine function in the cow

Modern protocols to synchronize ovulations for timed artificial insemination and timed embryo transfer that include manipulations in the proestrus period (i.e., between luteolysis and estrus) affect fertility in cattle. Specifically, stimulating pre-ovulatory follicle growth and exposure to estrogens after CL regression increase the proportion of cows pregnant and decrease late embryo mortality. Such effects may be due to both pre-ovulatory actions of estrogens and post-ovulatory actions of progesterone, as concentrations of the later hormone may be changed in response to manipulations conducted during proestrus. In the first portion of this paper we describe strategies used recently to manipulate the proestrus period in protocols for synchronization of ovulation, and to present evidence of their effects on fertility. Manipulations of timing and prominence of sex steroids during the proestrus and early diestrus that affect fertility may act on targets such as the endometrium. This tissue expresses receptors for both estrogens and progesterone and these hormones change endometrial function to support conceptus growth and pregnancy maintenance. However, specific cellular and molecular mechanisms through which fertility is affected via manipulations of the proestrus are poorly understood. In the second portion of this paper we describe a well-defined animal model to study changes in endometrial function induced by manipulations conducted during the proestrus. Such manipulations induced endometrial changes on sex steroid receptors expression, cell proliferation, oxidative metabolism and eicosanoid synthesis in the uterus, but not on glucose transport to uterine lumen . In summary, evidence is accumulating to support a positive role of increasing duration and estrogen availability during the proestrus on fertility to synchronization protocols. Such positive effects may be through changes in endometrial function to stimulate conceptus growth and survival.