Transition period produces changes in blood and body composition in mares / Período de transição produz alterações na composição do sangue e do corpo em éguas

Clinical and metabolic evaluation is necessary for the monitoring of pregnant and lactating mares, as they reflect the health of the animal. The body condition of the mare is an indicator of reproductive efficiency. The study aimed to determine the possible variations in body and metabolic condition in Mangalarga Marchador mares during the transition period. Forty-eight mares distributed in two groups were used: Maintenance Group (MG), composed of non-pregnant and non-lactating mares, and Transition Group (TG), formed by pregnant mares and who after delivery became lactating. Analyzes were performed in the times T-60, T-30 and T-15 before delivery, first six hours (T0) after delivery and T15, T30 and T60 days after delivery. MG was evaluated only at one time (T-60). Body weight and fat-free mass differed (P<0.05) between the groups. The percentage of fat was lower in MG. Mares had a higher fat percentage in TG at T-60 and T-30 times. There was a difference (P<0.05) in the amount of cholesterol between MG and TG (T0, T15 and T30). Triglycerides were different between the groups. TG showed higher concentrations of non-esterified fatty acids (P<0.05). There was a higher amount of glucose in TG (delivery and lactation) when compared to mares in MG. Changes in body condition and metabolic constituents occurred in the animals resulting from physiological adaptations of the transition period. The energetic components are the most affected from the transition period, with intense fat mobilization to supply the body demands.(AU)

Avaliações clínicas e metabólicas são necessárias para o monitoramento de éguas gestantes e lactantes, pois refletem a saúde do animal. A condição corporal da égua pode ser um indicador da eficiência reprodutiva. O estudo objetivou determinar as possíveis variações na condição corporal e metabólica em éguas Mangalarga Marchador durante o período de transição. Foram utilizadas 48 éguas distribuídas em dois grupos: Grupo em Manutenção (GM) composto por éguas não gestantes e não lactantes; Grupo em Transição (GT) formado por éguas gestantes e que após o parto tornaram-se lactantes. As análises foram realizadas nos tempos T-60, T-30 e T-15 antes do parto, primeiras seis horas (T0) após o parto e T15, T30 e T60 dias após o parto. O GM foi avaliado apenas uma vez (T-60). O peso corporal e a massa livre de gordura diferiram (P<0,05) entre os grupos. O percentual de gordura foi menor em GM. As éguas apresentaram maior porcentagem de gordura no GT no T-60 e no T-30. Houve diferença (P<0,05) na quantidade de colesterol entre GM e GT (T0, T15 e T30). Triglicérides foram diferentes entre os grupos. GT apresentou maiores concentrações de ácidos graxos não esterificados (P<0,05). Houve maior quantidade de glicose no GT (parto e lactação) quando comparada às éguas no GM. Mudanças na condição corporal e nos constituintes metabólicos ocorreram nos animais resultantes de adaptações fisiológicas do período de transição. Os componentes energéticos são os mais afetados neste período, existindo intensa mobilização de gordura para suprir demandas corporais.(AU)

Ensaios preliminares em ratas wistar com extrato hidroetanólico de calunga (Simaba ferruginea St. Hil. ) v. o., nas fases gestacionais de implantação, organogênese e período fetal: interferências na prole / Preliminary trials on female Wistar rats with hydroethanolic extract from "calunga" (Simaba ferruginea St. Hil. ) in the gestational stages of implantation, organogenesis and fetal period: interference on offspring

RESUMO A susceptibilidade dos conceptos a agentes químicos varia muito em cada estágio do desenvolvimento. Devido a isto, a maioria dos países passou a exigir a análise do potencial para afetar todos os aspectos da reprodução (espermatogênese, acasalamento, prenhez, parto e lactação) para o desenvolvimento de novos medicamentos e fitoterápicos. O presente trabalho objetivou avaliar o efeito do extrato hidroetanólico de Simaba ferruginea St. Hil (calunga) (EHSF) v.o., em ratas da linhagem Wistar tratadas durante a prenhez e verificar a interferência no desenvolvimento intra-uterino da prole. As ratas foram tratadas com EHSF 50 e 100 mg Kg-1 ou água destilada, do seguinte modo: a) do 1º ao 6º dia de prenhez (período da formação do blastocisto e implantação); b) do 8º ao 16º dia de prenhez (fase embrionária de organogênese); c) do 15º ao 19º dia de prenhez (fase do desenvolvimento fetal). O tratamento do 1º ao 6º dia, mostrou redução no número de fetos com ambas doses e não alterou o peso do útero / ovário nem peso corporal das mães. Quando as ratas foram tratadas na fase da organogênese verificou-se, redução estatisticamente significante do número de fetos vivos com a dose 50 mg Kg-1, e o aparecimento de fetos mortos em 30% das fêmeas tratadas com EHSF 50 mg Kg-1 e em 20% nas fêmeas tratadas com a dose de 100 mg Kg-1, não houve alteração no peso do útero / ovário nem no peso corporal das matrizes. Finalmente, o tratamento no período fetal não afetou o número de filhotes vivos, não provocou malformações anatômicas visíveis a olho nu, nem reabsorção fetal; porém, observou-se que 10% das mães tratadas com 50 mg Kg-1 apresentaram 2 fetos mortos e 20% das mães tratadas com 100 mg Kg-1 apresentaram, em média, 4 fetos mortos. Com estes dados, pode ser concluído que o EHSF apresenta baixa ou nenhuma toxicidade materna para ratas Wistar, embora seja letal para alguns descendentes, independente da fase da prenhez em que foram realizados os tratamentos ...

ABSTRACT The susceptibility of concepts to chemical agents varies a lot at each development stage. Because of that, most countries started requiring the analysis of potential to affect all aspects of reproduction (spermatogenesis, mating, pregnancy, birth and lactation) for the development of new drugs and herbal medicines. This study aimed to evaluate the effect of the hydroethanolic extract of Simaba ferruginea St. Hil ("calunga") (EHSF) on female Wistar rats treated during pregnancy in order to check the interference on the intrauterine development of the offspring. The rats were treated with EHSF 50 and 100 mg/kg-1or distilled water, as follows: a) from day 1 to day 6 of pregnancy (period of blastocytes formation and implantation); b) from day 8 to day 16 of pregnancy (embryonic phase of organogenesis); c) from day 15 to day 19 of pregnancy (fetal development phase). The treatment from day 1 to day 6 showed reduction on the amount of fetuses with both doses and it did not alter neither the weight of the uterus / ovary nor the body weight of the mothers. When the female rats were treated in the organogenesis phase, it was verified both statistical significant decrease on the number of live fetuses for the 50 mg / Kg-1, and also appearance of dead fetuses in 30% of the female rats treated with EHSF 50 mg / Kg-1. In 20% of the female rats treated with 100 mg / Kg-1, there was no alteration neither in the weight of the uterus / ovary or in the body weight of the matrixes. Finally, the treatment in the fetal period did not affect the number of live descendants, or caused anatomical malformations visible to naked eye and fetal reabsorption. However, 10% of the mothers treated with 50 mg / Kg-1presented 2 dead fetuses and 20% of the mothers who had 100 mg / Kg-1showed, on average, 4 dead fetuses. With this data, we can conclude that EHSF presents low maternal toxicity for Wistar rats, although being fatal to some descendants, not mattering in which pregnancy phase the treatments have been performed, being more evident in the earlier phases. For this reason, it is recommended to avoid the use of this plant in pregnancy case.

Antepartal insulin-like growth factor concentrations indicating differences in the metabolic adaptive capacity of dairy cows

Cows with different Insulin-like Growth Factor-I (IGF-I) concentrations showed comparable expression levels of hepatic growth hormone receptor (GHR). Suppressor of cytokine signaling 2 (SOCS2), could be responsible for additional inhibition of the GHR signal cascade. The aims were to monitor cows with high or low antepartal IGF-I concentrations (IGF-I(high) or IGF-I(low)), evaluate the interrelationships of endocrine endpoints, and measure hepatic SOCS2 expression. Dairy cows (n = 20) were selected (240 to 254 days after artificial insemination (AI)). Blood samples were drawn daily (day -17 until calving) and IGF-I, GH, insulin, thyroid hormones, estradiol, and progesterone concentrations were measured. Liver biopsies were taken (day 264 +/- 1 after AI and postpartum) to measure mRNA expression (IGF-I, IGFBP-2, IGFBP-3, IGFBP-4, acid labile subunit (ALS), SOCS2, deiodinase1, GHR1A). IGF-I concentrations in the two groups were different (p 0.05). Thyroxine levels and ALS expression were higher in the IGF-I(high) cows compared to IGF-I(low) cows. Estradiol concentration tended to be greater in the IGF-I(low) group (p = 0.06). It was hypothesized that low IGF-I levels are associated with enhanced SOCS2 expression although this could not be decisively confirmed by the present study.

Porcine uterine and placental extracellular matrix molecules throughout pregnancy / Moléculas de la matríz extracelular placentaria y uterina durante la preñez porcina

The molecules that constitute the extracellular matrix are important in several functions related to tissue support and cell-cell, cell-extracellular matrix interaction. Among the macromolecules that constitute the mentioned matrix we find osteopontin, fibrinogen and collagen. The present study was undertaken to analyze the rol of osteopontin, fibrinogen and collagen in uterine-placental interface during normal porcine gestation. Uterine and placental tissues from crossbred gilts of 30 (n=5), 60 (n=5), 70 (n=5) and 114 (at term, n=5) days of gestation were used. Macroscopic analysis of the embryos/fetuses allowed us to determine their gestational age by means of the crown-rump lenght. Haematoxylin-Eosin and Masson's Trichrome dyes along with light microscopy were used to structure analysis of every selected period of gestation. A spacial and temporal study of osteopontin and fibrinogen was performed through immunohistochemical technique. Determination of collagen fibers was carried out through Picrosirius red technique and polarizing microscopy. Results were expressed as semi-quantitative. Higher expression of osteopontin was observed at early periods of gestation, mainly in uterine and placental villi, endometrial gland epithelium and histotroph. Fibrinogen expressed abundantly in fetal mesenchyme in every period analyzed and in fetal and maternal vessels at Day 70. Negative expression of collagen fibers was observed in villi, however increasing expression of thick fibers throughout pregnancy was detected in uterine stroma and myometrium. These results confirm the importance of osteopontin, fibrinogen and collagen in the support of uterine and placental structures and in the suitable maintenance of pregnancy.

Las moléculas que constituyen la matriz extracelular son importantes en varias funciones relacionadas con el soporte del tejido y la interacción célula-célula, célula-matriz extracelular. Entre las macromoléculas que constituyen la matriz mencionada se encuentra la osteopontina, el fibrinógeno y el colágeno. Este estudio se realizó para analizar el rol de la osteopontina, el fibrinógeno y el colágeno en la interface útero-placentaria durante la gestación porcina normal. Tejidos uterinos y la placentarios de hembras porcinas cruzadas de 30 (n=5), 60 (n=5), 70 (n=5) y 114 (a término, n=5) días de gestación fueron utilizados. El análisis macroscópico de los embriones/fetos nos permitió determinar la edad gestacional por medio de la longitud cráneo-rabadilla. Tinciones de Hematoxilina-Eosina y Tricrómico de Masson con microscopía de luz se utilizó para estructurar el análisis de cada periodo de tiempo seleccionado de la gestación. Un estudio espacial y temporal de la osteopontina y el fibrinógeno se realizó mediante técnicas de inmunohistoquímica. La determinación de fibras colágenas se llevó a cabo a través de la técnica Picrosirius rojo por microscopia de polarización. Los resultados se expresaron como semi-cuantitativos. La expresión de osteopontina se observó en los primeros períodos de gestación, principalmente en las vellosidades del útero y la placenta, epitelio de las glándulas endometriales e histotrofos. El fibrinógeno se expresa abundantemente en mesénquima fetal en todos los períodos analizados y en los vasos fetales y maternos el día 70. Una expresión negativa de fibras colágenas se observó en las vellosidades, sin embargo, un aumento de expresión de las fibras gruesas durante la gestación se detectó en el estroma uterino y el miometrio. Estos resultados confirman la importancia de la osteopontina, fibrinógeno y colágeno en el soporte de las estructuras del útero y placenta, así como el mantenimiento adecuado durante la gestación.

Efeito do exercício físico contínuo e intervalado no peso e perfil bioquímico de ratas Wistar prenhes e consequências no peso da prole / Effect of continuous and interval physical exercise on weight and biochemical profile of pregnant Wistar rats and consequences on fetal body weight

INTRODUÇÃO: A prática de atividade física é reconhecida como fator importante para a preservação, recuperação e manutenção da saúde. O estímulo à prática de exercícios é crescente, mas quando relacionado à gravidez, dúvidas surgem sobre os efeitos deletérios ou salutares na mãe e no feto. OBJETIVO: O objetivo deste trabalho foi avaliar os efeitos do exercício físico intervalado e contínuo no perfil bioquímico de ratas Wistar prenhes e avaliar o efeito destes exercícios no peso da placenta e dos filhotes. MÉTODOS: Utilizou-se 45 ratas Wistar divididas em grupos de 15 animais segundo o tipo de exercício: controle (GC), exercício contínuo (GCO) e exercício intermitente (GIN). Os exercícios constituíram-se de natação forçada, cinco dias por semana, em piscinas individuais: exercício contínuo (duração de 45 minutos diários com sobrecarga de 5 por cento do peso corporal) e intermitente (45 minutos com estímulos de 15 segundos de exercício e 15 de repouso com sobrecarga de 15 por cento do peso corporal). O exercício foi praticado do primeiro ao 20º dia de prenhez. Após este período avaliou-se o peso e os níveis de glicemia, colesterol total, LDL-C, HDL-C e triglicérides das ratas, assim como o peso da placenta e dos filhotes. RESULTADOS: Não se observou modificação no peso das mães. Houve redução significativa nos níveis de LDL-C. O peso das placentas não variou, mas os pesos dos filhotes variaram estatisticamente entre os três grupos (4,153 ± 0,649; 3,682 ± 0,070 e 3,453 ± 0,052, respectivamente, para os filhos de mães do GC, GIN e GCO). CONCLUSÕES: Conclui-se que a prática do exercício físico contínuo e intermitente por ratas prenhes, neste modelo experimental, não interferiu no peso corpóreo das mesmas, mas interferiu no peso dos filhotes ao nascer.

Exercise training is known for its benefits to the body and mind. However, little is known about the effects of endurance training intensity on pregnancy. We tested the effects of continuous and intermittent exercises (maternal swimming) on the biochemical profile of pregnant Wistar rats and the effects of these exercises on the fetal body weight. The pregnant females (n=60) were divided in control group (GC), continuous exercise group (GCON) and intermittent exercise group (GIN). GC group rats did not practice exercises. GON group rats practiced continuous swimming for 45 minutes a day (five days a week) carrying a bag with 5 percent of its body weight. GIN group rats practiced intermittent swimming (15 seconds of swimming and 15 seconds stopped) for 45 minutes a day (five days a week) carrying a bag with 15 percent of its body weight. These exercises were made from the day one until 20º day of pregnancy. At the end of this period, we analyzed the mother's glycemia, cholesterol, HDL-C, LDL-C and triglycerides. We also analyzed fetal body weight. No significant modifications on glycemia and plasma lipids (except for LDL-C) were observed in the tree groups. We observed reduction on the fetal body weight in the pups that had their mothers practicing exercises: fetal body weight in GC > GIN > GON (4,153 ± 0,649; 3,682 ± 0,070 and 3,453 ± 0,052 respectively). These results showed that the continuous and intermittent exercise only performed in pregnancy period decreases fetus body weight.

Proporção volumétrica dos constituintes do corpo lúteo de vacas Nelore nos terços inicial, médio e final da gestação / Volumetric proportion of the corpus luteum of Nelore cows in the first, second and third trimester of gestation

A proporção volumétrica dos constituintes do corpo lúteo foi estudada em 48 ovários de vacas Nelore gestantes, coletados em frigorífico e distribuídos em três grupos, considerando-se o terço da gestação. No primeiro terço, utilizaram-se 11 animais em gestação de até 90 dias; no segundo terço, 20 animais em gestação entre 91 e 180 dias, e no terceiro terço 17 animais em gestação entre 181 e 261 dias. O corpo lúteo foi dissecado e submetido a processamento histológico para avaliação em microscopia óptica. Os animais em gestação de até 90 dias apresentaram maior proporção volumétrica de células endoteliais e pericitos, e nos acima de 181 dias de gestação ocorreu menor proporção de citoplasma (42,7 por cento) e núcleo (5,1 por cento) de células lúteas esteroidogênicas, bem como aumento do tecido conjuntivo e fibroblastos (47,7 por cento).

The volumetric proportion of the corpus luteum was evaluated in 48 ovaries from pregnant Nelore cows slaughtered in abattoirs, and divided into three groups, considering the trimester of gestation, and classified by the size of the fetus: First trimester - eleven animals with gestation up to 90 days; Second trimester - twenty animals with gestation between 91 and 180 days, and Third trimester - 17 animals with gestation between 181 and 261 days. The corpus luteum was dissected and submitted to histological processing and evaluations under light microscopy. The animals with gestation up to 90 days presented a higher proportion of endotelial cells and pericites. In the Third trimester there occurred a smaller proportion of cytoplasm (42,7 percent) and nucleus (5,1 percent) of steroidogenic luteal cells, and an increase in the conjunctive tissue, fibroblasts (47,7 percent).

Avaliação da reutilização de implantes contendo progestágenos na taxa de prenhez em vacas de corte / Evaluation of used progestagen implants on pregnancy rate in beef cows

Duzentos e vinte e uma vacas (78 paridas com bezerros entre 40 e 90 dias de idade e as demais secas vazias) Nelore (Bos taurus indicus) e mestiças Charolês (Bos taurus taurus) foram utilizadas para avaliar a reutilização de implantes auriculares de silicone impregnados com progestágenos para controle farmacológico do ciclo estral e ovulação sobre a taxa de prenhez. Os tratamentos experimentais consistiram de três protocolos para sincronização do cio e inseminação artificial em tempo fixo (IATF). No tratamento 1 (T1; n=73) as vacas receberam um implante auricular de Crestar® (3 mg de norgestomet); no tratamento 2 (T2; n= 75) as vacas receberam um implante auricular de Crestar® já utilizado previamente; e no tratamento 3 (T3; n=73) as vacas receberam dois implantes auriculares de Crestar® também utilizados previamente. Além dos implantes, as vacas receberam aplicação intramuscular (i.m) 2 mL de progesterona (25 mg/mL) + 2 mL de benzoato de estradiol i.m (1 mg/mL) no momento da colocação dos implantes. Os implantes foram removidos após 8 dias junto a uma aplicação de 2,0 mL de Preloban® i.m (150 g de D-cloprostenol). Após 24 h da remoção do implante, aplicou-se 1 mL de Estrogin® i.m (1 mg de benzoato de estradiol). A IATF foi realizada 54-56 h após a retirada dos implantes. Não houve diferença na taxa de prenhez das vacas, sendo 39,72%, 34,21% e 36,98% para os tratamentos T1, T2 e T3, respectivamente. A reutilização de implantes com progestágeno (Crestar®) não alterou a taxa de prenhez de vacas aptas à reprodução.

Two-hundred and twenty-one (78 suckling - 40 to 90 days and 143 not suckling ) Nelore (Bos taurus indicus) and crossbred Charolais (Bos taurus taurus) cows were used to evaluate the reutilization of progestagen implants to pharmacological control of the estrus cycle and ovulation on pregnancy rate. Cows were randomly assigned to one of three protocols for estrous synchronization and pre-fixed time artificial insemination (FTAI) was performed. In treatment 1 (T1; n=73) cows were implanted with Crestar® (3 mg de norgestomet); in treatment 2 (T2; n= 75) cows were implanted with already used Crestar®, and in treatment 3 (T3; n=73) cows received two Crestar® implants, also both previously used. All cows were injected with 2 mL of progesterone (25mg/mL) + 1 mL estradiol benzoate (1 mg/mL i.m.) at the time of implants insertion, intramuscular (i.m). Implants were removed after 8 days and 2 mL of Preloban® (150 g de D-cloprostenol) were administered i.m. Twenty-four hours after implants removal, cows were injected with 1 mL (i.m.) of Estrogin® (1mg of estradiol benzoate). The FTAI was performed 54-56 h after implants removal. There was no difference (P>0.05) on cow’s pregnancy rate among treatments. Pregnancy rates were 39.72, 34.21 and 36.98% for T1, T2 and T3, respectively. Progestagen implants reutilization (Crestar®) did not affected pregnancy rate in beef cows ready for reproduction.

Taxa de gestação em cabras Alpinas e Saanen tratadas com hCG no terceiro dia após o estro / Pregnancy rate and progesterone concentration of Alpine and Saanen goats treated with hCG the third day after estrus

Avaliou-se o efeito da aplicação da gonadotrofina coriônica humana (hCG) sobre a taxa e duração da gestação e sobre a concentração plasmática de progesterona (P4) em cabras lactantes das raças Alpina (83) e Saanen (60), na estação de acasalamento induzida pelo programa de fotoperíodo artificial. Os animais foram distribuídos em dois tratamentos após a cobrição; as cabras do tratamento 1 (T1 controle) receberam solução salina via intramuscular (1ml), e as do tratamento 2 (T2) receberam 250UI do hCG, no terceiro dia no pós-estro. As taxas de gestação, detectadas por exame ultra-sonográfico, realizado no 35° após a cobrição, para as cabras das raças Alpina e Saanen controle e tratadas, foram de 80,4; 70,3; 72,7; 81,5 por cento, respectivamente, não diferindo entre os tratamentos e entre as raças (P>0,05). A taxa média de gestação foi 77,2 e 75,0 por cento para os animais controle e tratados, respectivamente. A duração da gestação não foi influenciada pelos tratamentos (P>0,05). As amostras de sangue para análise da concentração plasmática de progesterona (P4) foram coletadas de cinco cabras Alpina por tratamento, no dia do estro (dia 0) e aos 3, 8, 15, 21, 42 e 60 dias após o estro. Não houve diferença na concentração plasmática média de P4 entre os tratamentos (P>0,05), sendo de 5,84ng/ml para T1 e 5,76ng/ml para T2. Observou-se diferença em relação aos dias de coleta (P<0,05). O hCG aplicado no terceiro dia pós-estro não alterou a taxa de gestação e nem a concentração de P4.

Efecto de la raza y el tipo de parto en la concentración de cobre y cinc en sangre, leche y lana de ovejas en confinamiento bajo restricción alimenticia / Effect of breed and type of lambing on the concentration of copper and zinc in blood, milk and wool of penned sheep under restricted feeding

Se utilizaron 3 ovejas Suffolk (SU) y 24 Rambouillet (RA) de parto sencillo y gemelar, en confinamiento y alimentadas con heno de avena y concentrado para determinar diferencias en el perfil de Cu y Zn en sangre, leche y lana. Los muestreos (peso corporal, sangre, leche y lana) se realizaron a los -15 o 0 y 15, 30, 45 y 60 días posparto (DPP). Las concentraciones de Cu y Zn, obtenidas por espectrometría de absorción atómica, y los pesos se sometieron a análisis de varianza de mediciones repetidas y de correlación múltiple. Las hembras SU y las de parto gemelar presentaron las mayores pérdidas de peso (interacción DPP X raza, P<.02, y DPP X parto, P=.0001). Para Cu se encontraron diferencias a) entre razas (SU=.65 ppm, RA=.42 ppm; P=.0001), entre tipos de parto (sencillo=.58 ppm, gemelar=.50 ppm; P=.03) y entre DPP (P=.0001) en sangre; b) entre DPP (P=.0001) en leche (media=.23 ppm) y c) entre DPP (P=.03) en lana (media=3.53 ppm). Para Zn se encontraron diferencias a) entre razas (SU=5.45 ppm, RA=6.2 ppm; P=.05) y DPP (P=.0001) en sangre; b) entre DPP (P=.0001) en leche (media=6.7 ppm) y c) entre razas (SU=109.3 ppm, RA=98.3 ppm; P=.0003) y DPP (P=.009) en lana. El análisis de correlación enfatizó la importancia de un adecuado manejo alimenticio durante la lactancia, pues a medida que las ovejas perdieron peso, los niveles sanguíneos de Cu y Zn (r=.99, P=.002, y r=.96, P=.0001, respectivamente) disminuyeron

Efeitos do exercício realizado durante o ciclo reprodutivo sobre o metabolismo lipídico: análise de estudos utilizando animais experimentais / Effects of exercise performed during the reproductive cicle: analysis of studies using animal models

O ciclo reprodutivo impöe várias adaptaçöes no metabolismo lipídico, garantindo modificaçöes específicas quanto ao direcionamento de substratos circulantes, na gestaçäo para o crescimento fetal, durante a lactaçäo para a produçäo de leite, e após o desmame para a reposiçäo de tecido adiposo. Por outro lado, durante o exercício há aumento na captaçäo de substratos pelo músculo. Desta forma, através desta revisäo objetiva-se responder à seguinte questäo: o exercício realizado durante o ciclo reprodutivo pode contribuir para o retorno ao estado pré-gestacional sem causar efeito deletério para o crescimento fetal e da cria? Conclui-se que o exercício é um fator importante para a reduçäo na deposiçäo de gordura que ocorre após o desmame näo causando efeitos deletérios ao crescimento normal

Myosin isoforms in uterine smooth muscle during pregnancy in rat.

Effects of uterine stretching and physiological hypertrophy on myosin isozyme were investigated in rat during pregnancy. Both nonpregnant and pregnant rat uteri express a single myosin band on native gels. Analysis of native myosin under denaturing conditions revealed two myosin heavy chains (MHCs) with molecular mass of 204 and 200 kDa respectively. Filamin, a 240 kDa protein co-electrophoreses with myosin on native gels. No correlation is found between regulatory myosin light chain phosphorylation and pattern of myosin isozymes or the MHC. The results suggest that uterine stretching and physiological hypertrophy during pregnancy do not induce any changes in uterine myosin isozyme.

Changes in uterine myosin isozymes from goat during early pregnancy.

Changes in the expression of native myosin, myosin heavy chains (MHCs) and myosin light chains (MLCs) were investigated in goat uterus during early pregnancy. Electrophoresis of native myosin under non dissociating conditions displayed two isozymes differing in their proportions during gestation. Three MHC isoforms were obtained following sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Whereas 204 kDa (a smooth muscle MHC) and 196 kDa (a non muscle MHC) were recorded in uterus from non pregnant goat, uterus of pregnant goat displayed a third 200 kDa smooth muscle MHC. Two conspicuous proteins (154 and 140 kDa respectively) in addition to MHCs were also obtained when the myofibrillar extracts were analysed either in the presence or absence of proteolytic inhibitors. Non pregnant goat uterus showed a basal level (ca.5%) of phosphorylation of regulatory myosin light chain. Uterine myosin from pregnant goat was recorded in a completely dephosphorylated state.

Carbohydrate-lipid interactions during gestation and their control by insulin

1. During the first two thirds of gestation, coinciding with a minimal accretion by the conceptus, the mother is in an anabolic state which is supported by her hyperphagia and the more efficient conservation of exogenous nutrients when she eats. During this phase maternal fat deposits are accumulated thanks to the enhancement in adipose tissue lipogenic and glycerolgenic activity. In contrast, in the latter part of gestation, the rapid fetal growth is sustained by the intense transfer of nutrients from maternal circulation. 2 Glucose is quantitatively the most abundant of the several substrates that cross the placenta and despite increased maternal gluconeogenesis this transfer is responsible for the maternal tendency to hypoglycemia. This causes a switch to a net catabolic state which is especially evident in the net breakdown of fat depots. 3. Enhanced release of adipose tissue lipolytic products, free fatty acids (FFA) and glycerol, facilitates the liver synthesis of triglycerides and their later release into circulation associated to very low-density lipoprotein (VLDL). Glycerol is also used as an important gluconeogenic substrate and FFAs are broken down through ß-oxidation for ketone body synthesis. Flow through these pathways becomes increased when food is withheld and this actively contributes to the availability of fuels to the fetus which becomes partially preserved from maternal metabolic insult. Increased liver production of VLDL-triglycerides and decreased extrahepatic lipoprotein lipase contribute to exaggerated maternal hypertriglyceridemia which, besides being a floating metabolic reserve for emergency conditions such as starvation, constitutes an essential substrate for milk synthesis around parturition in preparation for lactation. 4. While the maternal anabolic tendencies found during the first two-thirds of gestation seem to be facilitated by hyperinsulinemia in the presence of a normal responsiveness to the hormone, it is proposed that most of the metabolic changes taking place during the last third of gestation seem to be caused by the insulin-resistant state which is consistently present at this stage, since its reversion caused by sustained exaggerated hyperinsulinemia also reverts several of these metabolic adaptations

A role for cytokines in early pregnancy.

Cytokines are expressed in a variety of cell types of the reproductive system, although in most instances their functions are not understood. There are, however, a few instances where a role in early pregnancy has been established. First, preimplantation conceptuses of ruminant ungulate species, such as cattle, sheep and goat, secrete a unique Type I interferon (IFN-tau). By mechanisms that are still unclear, IFN-tau prevents the destruction of the corpus luteum and hence ensures the continued production of progesterone which is essential for continuation of pregnancy. Most like the IFN-tau prevent lutcolysis by modulating the output of a luteolytic hormone, prostaglandin F2 alpha, from the uterus. Depsite this involvement in pregnancy, the IFN-tau possess similar antiproliferative and antiviral activities to other Type I IFN, 1 lambda e.g. IFN-alpha. There are 4-5 genes for IFN-tau in sheep and cattle whose promotor regions are highly conserved and distinct from those of other Type I IFN. These genens are not virally inducible and are expressed only in the trophectoderm (outer epithelium of the developing placenta) from the time of blastocyst hatching to implantation. Leukemia inhibitory factor (LIF) is a multi-functional cytokine which is expressed by uterine endometrium of pregnant mice around day 4 of pregnancy. Female mice lacking a functional LIF gene are fertile but their blastocysts fail to implant, strongly implicating the cytokine in maternal control of implantation. Colony stimulating factors (CSF) are a family of proteins (GM-CSF, CSF-1, G-CSF, and IL-3) that stimulate the cellular proliferation and induction of terminal differentiation of hemopoietic progenitor cells. CSF-1 is expressed in the uterine endometrium of the mouse and human during early pregnancy and its receptor, fms, is present on trophoblast. The osteopetrotic mouse, which represents a natural "knockout" of the CSF-1 gene, exhibits a low rate of fetal implantation and poor fetal viability. It seems likely that CSF-1 expression by the uterus influences growth and differentiation of the placenta. Although different species may utilize different strategies for ensuring developmental and endocrinological coordination between the embryo and the mother, these three examples illustrate that cytokines are likely to be major participants as autocrine factors that direct the events of early pregnancy and not simply as modulators of the maternal immune system.

Impact of protein deficiency and exposure to hexachlorocyclohexane or malathion on lipid metabolism in pregnant rats.

Dietary intake of three oral doses of hexachlorocyclohexane (HCH) (60 mg/kg body wt) or malathion (500 mg/kg) by normal and protein-deficient diet fed pregnant rats on the 6th, 10th and 14th day of gestation resulted in the impairment of lipid metabolism, viz. hypercholesterolemia and hypertriglyceridemia. The cholesterol, triglyceride and phospholipid contents in serum, brain, liver, kidney and uterus were increased significantly by HCH and malathion exposure, irrespective of the protein content in the diet. The incorporation of [1,2-14C]acetate into the hepatic lipids was stimulated by both HCH and malathion, suggesting a higher rate of lipid synthesis in the liver of normal and protein-deficient diet fed dams. The low protein content in the diet intensified the pesticide-induced changes and more severe alterations were noticed in HCH exposed dams than in malathion exposed dams.

Efectos del frío sobre el metabolismo de la triiodotironina en la rata preñada / Effects of cold on triiodothyronine metabolism in the pregnant rat

Sixteen Wistar rats were studied in the last week of pregnancy. Another group of 6 nonpregnant animals served as control. Eight pregnant and 6 control ratas were kept in the cold room at 4 degrees C for 4 days, while 8 pregnant rats remained at 22 degrees C. After blocking the thyroid gland with potassium perchlorate to prevent iodine reutilization, a dose of 4 microCi of 125I-T3 was injected i.p. Thereafter, animals were placed in individual metabolic cages for separate 24 h collection of urine and feces. Heparinized blood samples were obtained at 4, 14, 24 and 28 h following tracer injection. Pregnant rats exposed to cold had a significant increase in T3 fractional turnover as compared to pregnants at 22 degrees C (p < 0.005) and to controls at 4 degrees C (p < 0.02). No changes were observed in space of distribution, serum concentration and body pool of T3. Degradation of this hormone, however, was significantly augmented (p < 0.05) in pregnants at 4 degrees C as compared to pregnants at 22 degrees C, although not when compared to controls at 4 degrees C. The urinary excretion of 125I was increased in pregnants in the cold (p <0.005) versus pregnants at 22 degrees C. The metabolic (p < 0.005), urinary (p < 0.001) and fecal (p < 0.05) clearances in pregnants at 4 degrees C were augmented with respect to the other two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Nivel proteínico dietario durante la gestación: su influencia sobre el reparto materno-fetal de sustratos / Dietary protein level during pregnancy: its influence on maternal-fetal exchange of substrates

En vista de la influencia que la concentración proteínica de la dieta materna tiene en el desarrollo del proceso gestacional y sus consecuencias sobre el crecimiento neonatal, se estudiaron, en ratas, las variaciones que el aporte de distintos niveles de proteína dietaria, 10%, 4% y 20% durante la gestación, ejerce en la eficiencia de utilización del alimento y en el reparto materno-fetal de sustratos. Con este propósito, se hicieron comparaciones entre las tres situaciones dietarias, y el efecto de la gestación se observó comparando las ratas gestantes con las no gestantes, con cada una de las dietas sometidas a estudio. Se determinó la ingesta, parámetros ponderales y eficiencia de conversión alimentaria (ECA) en ratas adultas, así como los parámetros ponderales de los neonatos. Según se pudo apreciar, tanto en los animales gestantes como en los no gestantes la ECA varió en función directa a la cantidad de proteína ingerida, mientras que durante la gestación se elevó en todas las situaciones dietarias. Por otra parte, la variabilidad ponderal de madres y neonatos, consecutiva a los cambios de proteína en la dieta, afectó también el reparto materno-fetal de sustratos. Este último fue modificado en los animales sometidos a las dietas que contenían 4% y 20% de proteína, dando lugar a una retención de sustratos en los tejidos maternos, en perjuicio del desarrollo neonatal