Allantochorionic differentiations of the pig studied morphologically and histochemically

Brambel, Charles E.

doi:10.1002/aja.1000520303

Cited by 48 publications

(24 citation statements)

References 12 publications

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“…In the diffuse epitheliochorial placenta of the pig there are no accumulations of extravasated maternal blood, but iron is present in the epithelium of the uterine glands and in the secretions released from them [Wislocki and Dempsey, 1946b]. This secretion is taken up by specialized areas of the chorion known as areolae, which overlie the mouths of the uterine glands [Brambel, 1933;Amoroso, 1952;Crombie, 1972]. Unfortunately there is little physiological information on placental iron transfer in the pig and it is thus impossible to assess the relative importance of this route.…”

Section: Placental Transport Of Ironsupporting

confidence: 43%

Ultrastructural Studies of the Placenta of the Ewe: Phagocytosis of Erythrocytes by the Chorionic Epithelium at the Central Depression of the Cotyledon

Burton¹,

Samuel²,

Steven³

1976

Exp Physiol

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Extravasated maternal blood, which escapes from capillaries and larger blood vessels within the tips of the maternal septa, is responsible for the characteristic pigmentation of the central depression of the ovine cotyledon in the last third of pregnancy. The chorionic epithelium of this region is actively engaged in the uptake and subsequent breakdown of maternal erythrocytes, which may represent an important source of iron for the foetus during the period of maximum intra-uterine growth.Haemophagous areas of the paraplacental chorion are a characteristic feature of the placenta of most carnivorous mammals [Amoroso, 1952]: in such areas the cells of the chorion appear to be actively engaged in the uptake and subsequent breakdown of extravasated maternal blood [Amoroso, 1955]. Such haemophagous areas have been studied in the cat and dog

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Section: Placental Transport Of Ironsupporting

confidence: 43%

Ultrastructural Studies of the Placenta of the Ewe: Phagocytosis of Erythrocytes by the Chorionic Epithelium at the Central Depression of the Cotyledon

Burton¹,

Samuel²,

Steven³

1976

Exp Physiol

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“…The irregular areolae show a maternal side enlarged by ridges and papilla-like structures (Amoroso 1961), whereas the fetal side is almost flat and enlarged by only a few small papillae (Perry 1981). The areolae are, in contrast to the interareolar placenta, therefore free of materno-fetal attachment (overview by Heuser 1927;Brambel 1933;Amoroso 1952;Friess et al 1981Friess et al , 1982Dantzer 1984).…”

Section: Introductionsupporting

confidence: 43%

“…The areola-gland subunits of the advanced (near-term) pig placenta appear, when seen through the fetal membranes (allantochorion/amniochorion), either as opaque circular spots measuring up to a few millimetres -regular areolae (Goldstein 1926;Amoroso 1952), or as translucent and variably formed larger structures -irregular areolae (Heuser 1927;Brambel 1933;Amoroso 1952). Areolae are formed from a fetal and a maternal part enclosing the areolar cavity.…”

Section: Introductionmentioning

confidence: 43%

Microvasculature of regular and irregular areolae of the areola-gland subunit of the porcine placenta: structural and functional aspects

Dantzer¹,

Leiser

1993

Anat Embryol

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To examine the vasculature of the areola-gland subunit of advanced pig placenta, tissues from ten animals between 43 and 112 days of gestation were prepared for histology and for scanning electron microscopy of vascular corrosion casts from both maternal and fetal sides. Regular areolae, tributary to one gland only, are round with a wide-meshed and smooth subepithelial capillary network on the maternal side, which is similar to the pre-implantative stage and bordered by an abrupt rim towards the inter-areolar maternal capillary network. On the fetal side, the capillary network follows papillae which protrude into the areolar cavity or converge to form a ring towards the areolar periphery. Irregular areolae, in contrast, have indistinct boundaries and are characterized by two or more gland openings. The maternal capillary network has moderate density and follows the corrugations, whereas the fetal capillary network is basically two-dimensional with some blunt sinusoidal protrusions. Vessel architecture of both areolar types implies facilitated external inflow of blood into the areola on arteriolar as well as on capillary levels, whereas the outflow from the areolar capillaries comprises venules converging into one or two areolar stem veins, and therefore conducts venous blood in a manner different from that of the inter-areolar region. It is suggested that this arrangement could favour vascular control mechanisms in uterus, placenta and fetus. On the basis of these observations and the discussion, it is suggested that these areola-specific vessel systems are important for sustaining the characteristic substance transfers in the areola, the secretion, metabolism and absorption, which according to the literature are not the same in the regular as in the irregular areolar type of the porcine areola-gland subunit of the placenta.

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“…and described in detail by Brambel (1933) on a 10 mm embryo corresponding to day 22 p.c. (after Marrable, 1971).…”

Section: Origin Of Regular and Irregular Types Of Areolamentioning

confidence: 42%

“…(after Marrable, 1971). In our study up to day 43 of pregnancy, irregular areolae were observed (compare with Figure 2b in Dantzer, 1984); however, they were scarce (compare Brambel, 1933;Tsutsumi, 1962;Dantzer, 1986) and represent a n undeveloped stage not yet typical for the later stages of irregular areolae (Dantzer and Leiser, 199313). When fully grown, irregular areolae are characterized by fifteen times the diameter of the regular areolae and are associated with two or more openings of uterine glands rather homogenous content (*) being secreted from the tubular uterine gland (arrow).…”

Section: Origin Of Regular and Irregular Types Of Areolamentioning

confidence: 45%

Initial vascularisation in the pig placenta: II. Demonstration of gland and areola‐gland subunits by histology and corrosion casts

Leiser

Dantzer²

1994

Anat. Rec.

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Tissues from 10 pregnant pigs between 9 1/2 and 43 days post coitum (p.c.) were prepared for histology and vascular corrosion casts to examine the vascularisation of the gland and areola-gland subunits of the early pig placenta. The endometrial vascular networks shown by casts were equal in both glandular and interglandular fields from days 9 1/2 to 14-15 p.c. This represents a cyclic stage uninfluenced by the early implanting embryo on day 13 p.c. By day 15 p.c., the first areola formation was observed both histologically and on casts. The maternal areolar and glandular capillary network developed into a widely meshed loose type, in contrast to the interareolar type which had a dense and parallel architecture. In some cases extremely large, crooked, and highly anastomosed maternal capillaries developed between these two networks. This specialized transition is thought to form the base for the ring-like seal formation (RSF) of the areolar periphery. A firm materno-fetal anchor therefore "seals" the areola and its glandular secretory contents from its interareolar surroundings. Therefore, the glandular and maternal areolar vasculatures are clearly discernable from that of the fetal areolar vasculature. The former are associated with the known maternao-fetal substance transfer of the porcine areolar-gland subunit. This association, however, seems to remain unspecialized in early placentation, as only the regular roundish areola--not the irregular areola--can be distinctly detected.

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Allantochorionic differentiations of the pig studied morphologically and histochemically

Cited by 48 publications

References 12 publications

Ultrastructural Studies of the Placenta of the Ewe: Phagocytosis of Erythrocytes by the Chorionic Epithelium at the Central Depression of the Cotyledon

Ultrastructural Studies of the Placenta of the Ewe: Phagocytosis of Erythrocytes by the Chorionic Epithelium at the Central Depression of the Cotyledon

Microvasculature of regular and irregular areolae of the areola-gland subunit of the porcine placenta: structural and functional aspects

Initial vascularisation in the pig placenta: II. Demonstration of gland and areola‐gland subunits by histology and corrosion casts

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