Functions of the placenta

Donnelly, Leo; Campling, Gillian

doi:10.1016/j.mpaic.2010.11.001

Cited by 10 publications

(11 citation statements)

References 10 publications

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“…The transport of almost all substances through the placental membrane involves one of four transport mechanisms: simple diffusion, facilitated diffusion, active transport and pinocytosis [9]. Transfer across the maternal-fetal barrier depends on the thickness and extent of the barrier as well as the concentration gradient or presence of active transport mechanisms [10]- [12].…”

Section: Introductionmentioning

confidence: 99%

Immunoglobulin Transport during Gestation in Domestic Animals and Humans—A Review

Borghesi¹,

Mario²,

Rodrigues³

et al. 2014

OJAS

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Maternal immunity is the main early defense against infectious agents in newborns. Immunoglobulin G (IgG) is indispensable for immune defense against infectious agents. IgG is transported through either the colostrum or the placenta. Immunoglobulins are antibodies, and the five different classes of these antibodies are IgG, IgA, IgM, IgD and IgE. Through their biological function of binding antigens, antibodies facilitate the removal of antigens from the body. The placenta is a temporary maternal-fetal organ, whose principal function is to allow the controlled exchange of metabolites between mother and embryo/fetus during gestation. The placenta types in different species are classified by the number of membranes separating the maternal and fetal blood circulation. Humans, lagomorphs and rodents have hemochorial placentas, which require a receptor for IgG transfer. In other animals, such as horse and pig (epitheliochorial placenta), ruminants (synepitheliochorial placenta) and carnivores (endotheliochorial placenta), antibodies are transferred via the colostrum and absorbed by passive diffusion. This review covers immunoglobulin transport in several types of placentas.

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Section: Introductionmentioning

confidence: 99%

Immunoglobulin Transport during Gestation in Domestic Animals and Humans—A Review

Borghesi¹,

Mario²,

Rodrigues³

et al. 2014

OJAS

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“…It might be due to a difference in types of placenta between mice (hemochorial placenta) and pigs (epitheliochorial placenta). The placenta is a materno-fetal organ consisting of two components: the maternal placenta, which develops from the maternal uterine tissue, and the fetal placenta, which develops from the blastocyst that forms the fetus [ 23 ]. In hemochorial placenta of mice, the fetal chorion is in direct contact with the maternal blood vessel.…”

Section: Discussionmentioning

confidence: 99%

Failure to maintain full-term pregnancies in pig carrying klotho monoallelic knockout fetuses

et al. 2021

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Background Small animals that show a deficiency in klotho exhibit extremely shortened life span with multiple aging-like phenotypes. However, limited information is available on the function of klotho in large animals such as pigs. Results In an attempt to produce klotho knockout pigs, an sgRNA specific for klotho (targeting exon 3) was designed and Cas9-sgRNA ribonucleoproteins were transfected into porcine fibroblasts. Transfected fibroblasts were cultured for one to 2 days and then directly used for nuclear transfer without selection. The cloned embryos were cultured in vitro for 7 days and analyzed to detect modifications of the klotho gene by both T7E1 and deep sequencing analysis. Modification succeeded in 13 of 20 blastocysts (65%), 8 of which (40.0%) were monoallelic modifications and 5 (25.0%) were biallelic modifications. Based on high mutation rates in blastocysts, we transferred the cloned embryos to 5 recipient pigs; 1 recipient was pregnant and 16 fetuses were recovered at Day 28 post transfer. Of the 16 fetuses, 9 were resorbing and 7 were viable. Four of 9 (44.4%) resorbing fetuses and 3 of the 7 (42.9%) viable fetuses had monoallelic modifications. Thus, 3 klotho monoallelic knockout cell lines were established by primary culture. A total of 2088 cloned embryos reconstructed with 2 frame-shifted cell lines were transferred to 11 synchronized recipients. Of the recipients, 7 of 11 eleven (63.6%) became pregnant. However, none of the pregnancies was maintained to term. To discover why klotho monoallelic knockout fetuses were aborted, expression of aging- and apoptosis-related genes and klotho protein in placentas from klotho monoallelic knockout and wild-type fetuses was investigated. Placentas from klotho monoallelic knockout fetuses showed negatively changed expression of aging- and apoptosis-related genes with lower relative expression of klotho protein. These results indicated that the reason why klotho monoallelic knockout fetuses were not maintained to term was possibly due to decreased klotho expression in placentas, negatively affecting aging- and apoptosis-related genes. Conclusions Klotho monoallelic knockout porcine fetal fibroblasts were successfully established. However, pigs carrying klotho monoallelic knockout fetuses failed to maintain full-term pregnancy and a decrease in klotho expression in placenta likely leads to pregnancy loss.

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“…Although lactate values of lambs from non-sheared ewes were numerically higher than those of lambs from sheared ewes, no statistical difference was detected. In placental hypoxia situation, it is believed an efficient regulatory mechanism takes place in metabolism of glucose and lactate, the main energy metabolites of fetus and placenta (22,23) . The needs of glucose for placenta, uterus and fetus represent up to 70% of the available glucose of the pregnant ewe.…”

Section: Discussionmentioning

confidence: 99%

Effect of Shearing During Pregnancy on Productive Performance in the Post-Partum Period of Ewes on Extensive Husbandry

et al. 2015

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The use of shearing during pregnancy has been described as a tool for improving productivity in sheep and for minimizing perinatal mortality in lambs through the increase of fetal development. This study assessed the effect of shearing around 74 days of gestation on the productive performance of ewes and lambs during the first month of life. Forty Corriedale ewes were inseminated in autumn in Southern Brazil. All ewes were kept together at the same pasture under extensive husbandry conditions. The ewes were randomly separated into two treatment groups: twenty animals were completely sheared at 74 ± 6 days of pregnancy, and twenty were kept without sheared during pregnancy, composing the control group. Ewes and their lambs were evaluated at three different times during the experiment: at birth, between 15 and 21 days post-partum and between 22 and 45 days post-partum. Ewes had their body condition score, body weight, placental weight, milk production and serum concentrations of beta-hydroxybutyrate measured, while lambs had hematocrit, hemoglobin, and plasma lactate and glucose, as well as body weight at birth and until wean determined. Values of hematocrit and hemoglobin were lower and body weight at birth and at wean was higher in the group of lambs born from sheared ewes. Placenta weight was higher in sheared ewes. Body condition score and beta-hydroxybutyrate showed no differences between groups. Milk production of sheared ewes (1.26 L/day) was higher than in control group (0.93 L/day). Shearing ewes at 74 days of pregnancy was efficient for the better development of lambs at post-birth, reducing perinatal mortality rates. Keywords: beta-hydroxybutyrate; lambs; milk yield; metabolism; placenta weight. GUYOTI, V.M. et al. Cienc. anim. bras. v.16,n.2, p. 217-224 abr./jun. 2015Resumo O uso da esquila durante a gestação tem sido descrita em ovelhas como ferramenta para aumentar a produtividade e minimizar a mortalidade perinatal em cordeiros por aumentar o desenvolvimento fetal. No presente estudo foi avaliado o efeito da esquila em torno dos 74 dias de gestação sobre o desempenho produtivo de ovelhas e no peso de seus cordeiros durante o primeiro mês de vida. Quarenta ovelhas Corriedale foram encarneiradas no outono do Sul brasileiro, sendo mantidas sob a mesma pastagem em condições extensivas. As ovelhas foram distribuídas aleatoriamente em dois grupos de tratamentos, sendo vinte ovelhas esquiladas aos 74 ± 6 dias de gestação e vinte mantidas sem esquila durante a gestação, compondo o grupo controle. Ovelhas e respectivos cordeiros foram avaliados em três períodos: no dia do parto, entre 15 e 21 dias pós-parto e entre 22 e 45 dias pósparto. Nas ovelhas, foram medidos o escore de condição corporal, o peso corporal e da placenta, a produção do leite e a concentração sérica de beta-hidroxibutirato, enquanto nos cordeiros foram determinados hematócrito, hemoglobina e concentrações plasmáticas de lactato e glicose, além de peso corporal ao nascimento até o desmame. Os valores médios de hematócrito e hemoglobina foram...

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Functions of the placenta

Cited by 10 publications

References 10 publications

Immunoglobulin Transport during Gestation in Domestic Animals and Humans—A Review

Immunoglobulin Transport during Gestation in Domestic Animals and Humans—A Review

Failure to maintain full-term pregnancies in pig carrying klotho monoallelic knockout fetuses

Effect of Shearing During Pregnancy on Productive Performance in the Post-Partum Period of Ewes on Extensive Husbandry

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