Light- and electron-microscopic study of the near-term paraplacenta of the domestic cat

Leiser, Rudolf; Enders, Allen C.

doi:10.1159/000145195

Cited by 26 publications

(10 citation statements)

References 27 publications

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“…The villous rather than saccular nature of this area suggests that it is a response of the paraplacental trophoblast cells to the leaking of maternal blood from the margins of the placenta. Although a detailed fine-structural analysis of the stages in the breakdown of the erythrocytes was not made in this study, the general pattern appeared similar to that reported in the cat [Leiser and Enders, 1980] and for other hemophagous regions by Burton [1982]. The few recently ingested erythrocytes in contrast to the extensive accumulation of phagolysosomes in various stages of degradation suggest that erythrocyte breakdown is quite slow.…”

Section: Discussionsupporting

confidence: 74%

Structure of the Midterm Placenta of the Spotted Hyena, <i>Crocuta crocuta, </i>with Emphasis on the Diverse Hemophagous Regions

Enders

Blankenship

Conley

et al. 2006

Cells Tissues Organs

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The hyena placenta is unique among carnivores in being hemochorial. It also has areas of erythrocyte uptake that differ from those seen in more commonly studied carnivores. The availability of timed midterm pregnancies made it possible to examine the organization of the placenta, the distribution of regions of columnar trophoblast and the nature of the heterophagous and hemophagous regions in well-preserved material. The labyrinth of the placenta is orderly arranged with periodic primary villi that have a surface of syncytial trophoblast. Secondary projections from the primary villi anastomose extensively. The junctional extreme of each primary villus forms an expanded tip covered by columnar trophoblast cells. Marginal to the hemochorial placenta, the paraplacenta is exposed to varying amounts of extravasated maternal blood which the cytotrophoblast cells ingest and destroy. Columnar trophoblast cells at the tips of the primary villi, in the villi of paraplacental margins of the labyrinth, in isolated patches within the labyrinth and beneath the allantochorionic plate are all capable of and are variably involved in erythrophagocytosis. Variations in the structure and the lectin histochemistry of the columnar trophoblast cells indicate variation depending on the exposure of these cells to erythrocytes and/or other histotrophic materials. The widespread distribution of the hemophagous regions suggests a nutritive function in addition to an iron transfer function of the columnar cytotrophoblast.

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Section: Discussionsupporting

confidence: 74%

Structure of the Midterm Placenta of the Spotted Hyena, <i>Crocuta crocuta, </i>with Emphasis on the Diverse Hemophagous Regions

Enders

Blankenship

Conley

et al. 2006

Cells Tissues Organs

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“…Thus, the polar zone of the chorioallantois of the cat exhibits pinocytotic activity (Leiser and Enders, 1980a), whilst the remainder of the paraplacenta is haemophagous (Leiser and Enders, 1980b). A prominent haemophagous organ occupies a central, antimesometrial position in the sea otter and other mustelids, in skunks, and in raccoons and allies (reviewed in Carter and Enders, 2016); these three families share a common ancestor (Eizirik et al, 2010).…”

Section: Areolae and Haemophagous Organsmentioning

confidence: 99%

Advances in flow cytometry in basic and applied equine andrology

2017

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Molecular phylogenetics has made a substantial contribution to our understanding of the relationships between mammalian orders and has generated trees that can be used to examine the evolution of anatomical and physiological traits. We here summarize findings on fetal membranes and placentation in Ferungulata, a clade comprising carnivores, pangolins, and even-and odd-toed ungulates. Their early ontogeny shows several conserved traits such as superficial attachment of the blastocyst, amnion formation by folding, a large allantoic sac and a temporary yolk sac placenta. In contrast, several characters of the chorioallantoic placenta are derived, including the diffuse and cotyledonary placental types in ungulates and zonary placenta in carnivores, specializations of the interhaemal barrier, the presence of areolae or haemophagous regions and lack of stromal decidual cells. Ungulates produce large amounts of placental proteins including placental lactogens and pregnancy-associated glycoproteins. Evolutionary innovations of the placental system may contribute to the high diversity of lifestyles within Ferungulata and be linked to the evolution of highly precocial offspring in ungulates.

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“…Consequently, the formation of corpora lutea (CL) and the functional luteal phases is reflected by different plasma progesterone (P4) profiles after days 10-12 post coitum (p.c.) (Paape et al 1975, Verhage et al 1976, coinciding with the time of blastocyst implantation (Leiser 1979). Significant differences between both profiles become visible around days 25-30 p.c., when pregnant cats have higher P4 levels (Verhage et al 1976).…”

Section: Introductionmentioning

confidence: 99%

Synthesis and reception of prostaglandins in corpora lutea of domestic cat and lynx

Zschockelt¹,

Amelkina²,

Siemieniuch³

et al. 2016

Reproduction

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Felids show different reproductive strategies related to the luteal phase. Domestic cats exhibit a seasonal polyoestrus and ovulation is followed by formation of corpora lutea (CL). Pregnant and non-pregnant cycles are reflected by diverging plasma progesterone (P4) profiles. Eurasian and Iberian lynxes show a seasonal monooestrus, in which physiologically persistent CL (perCL) support constantly elevated plasma P4 levels. Prostaglandins (PGs) represent key regulators of reproduction, and we aimed to characterise PG synthesis in feline CL to identify their contribution to the luteal lifespan. We assessed mRNA and protein expression of PG synthases (PTGS2/ COX2, PTGES, PGFS/AKR1C3) and PG receptors (PTGER2, PTGER4, PTGFR), and intra-luteal levels of PGE 2 and PGF 2α . Therefore, CL of pregnant (pre-implantation, post-implantation, regression stages) and non-pregnant (formation, development/maintenance, early regression, late regression stages) domestic cats, and prooestrous Eurasian (perCL, pre-mating) and metoestrous Iberian (perCL, freshCL, post-mating) lynxes were investigated. Expression of PTGS2/COX2, PTGES and PTGER4 was independent of the luteal stage in the investigated species. High levels of luteotrophic PGE 2 in perCL might be associated with persistence of luteal function in lynxes. Signals for PGFS/AKR1C3 expression were weak in mid and late luteal stages of cats but were absent in lynxes, concomitant with low PGF 2α levels in these species. Thus, regulation of CL regression by luteal PGF 2α seems negligible. In contrast, expression of PTGFR was evident in nearly all investigated CL of cat and lynxes, implying that luteal regression, e.g. at the end of pregnancy, is triggered by extra-luteal PGF 2α .

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Light- and electron-microscopic study of the near-term paraplacenta of the domestic cat

Cited by 26 publications

References 27 publications

Structure of the Midterm Placenta of the Spotted Hyena, <i>Crocuta crocuta, </i>with Emphasis on the Diverse Hemophagous Regions

Structure of the Midterm Placenta of the Spotted Hyena, <i>Crocuta crocuta, </i>with Emphasis on the Diverse Hemophagous Regions

Advances in flow cytometry in basic and applied equine andrology

Synthesis and reception of prostaglandins in corpora lutea of domestic cat and lynx

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