Co-expression pattern of dopamine beta-hydroxylase (DßH) and neuropeptide Y (NPY) within sympathetic innervation of ovary and umbilical cord of the European bison (Bison bonasus L.).

Co-expression of dopamine ß-hydroxylase (DßH) and neuropeptide Y (NPY) has never been examined in ovary (OV) and umbilical cord (UC) of the European bison (Eb), the endangered wild species. The OV and UC samples were harvested from seasonally eliminated Eb females (45-120 days post coitum). Frozen histological sections were examined by double fluorescent immunohistochemistry (dF-IHC), using the primary mouse anti-DßH monoclonals and rabbit anti-NPY polyclonals and then the immunocomplexes were visualized with FITC and CY3 fluorophores, respectively. Numerous DßH immunoreactive nerve fibers (DßH-IRs) and a little less frequent NPY-IRs were found in the bundle-like structures, innervating mainly perivascular regions of the OV. The NPY-IRs constantly co-expressed DßH, while some DßH-IRs did not express NPY. This specific pattern of innervation was observed both in the stromal and cortical regions of the OV. The simultaneous co-expression of DßH and NPY were also detected in the UC, in which specific single or bundle-like structures ran along the smooth muscles of blood vessels. The spatial-specific co-expression of DßH and NPY in OV and UC, may suggest that these markers are involved in the control of vascularization that regulates nourishing blood circulation required for proper pregnancy maintenance and efficient embryo/fetus development in the Eb.

Restricted innervation of uterus and placenta during pregnancy: evidence for a role of the repelling signal Semaphorin 3A.

Because data from the literature suggest a lack of innervation of the placenta, we have investigated placenta, umbilical cord, and uterus to identify the molecules that play a role in regulating innervation in these organs. Neuropilin-1 and Plexin-A1 are cell surface proteins that form a receptor complex for Semaphorin 3A (Sema 3A), a secreted molecule mediating repelling signals for axonal growth cones. We have analyzed the expression of Neuropilin-1, Plexin-A1, and Semaphorin 3A in the above-mentioned tissues on the hypothesis that these molecules could regulate innervation in these organs during gestation. We found that nervous fibers are only present in the proximal part of the umbilical cord, close to the newborn, and in nongestational uterine tissues. In contrast, nervous fibers are not present in the distal segment of the umbilical cord, in the placenta and in the uterine tissues during gestation. We also found that Sema 3A receptors, Neuropilin-1 and Plexin-A1, are expressed by the nervous fibers of the proximal part of the umbilical cord, whereas Sema 3A is secreted in the umbilical cord, in the placenta, and in gestational uterine tissues. We report that a factor secreted in the umbilical cord induces the collapse of neurite growth cones in vitro and provide evidence that this factor is Sema 3A. In summary, our results suggest that the chemorepulsive signals mediated by Sema 3A play an important role in preventing nerve fibers growth in the umbilical cord and in gestational uterine tissues. The inhibition of nerve growth into the myometrium as well as into the placenta could be considered fundamental processes to preserve the fetus from external stressful events.

Calcitonin gene-related peptide-, neuropeptide Y- and tyrosine hydroxylase-immunoreactive nerve fibers in the human umbilical cord.

The distribution of nerve fibers positive for calcitonin gene-related peptide (CGRP), which is a vasodilator peptide, neuropeptide Y (NPY), which is a vasoconstrictor peptide, and tyrosine hydroxylase (TH), which is a key enzyme for the synthesis of the neurotransmitter of adrenergic nerves, was studied in the fetal side, middle part, and placental side of the human umbilical cord using immunohistochemistry. In the fetal side of the umbilical cord, CGRP-, NPY-, and TH-positive fibers were observed in the smooth muscle of the media of the umbilical artery and in the margins of the Wharton jelly. They were not observed around the umbilical vein or in the middle part or placental side of the umbilical cord. These results demonstrate the presence of the vasoactive peptides CGRP and NPY, as well as of the enzyme TH in the fetal side of the umbilical vessel. The presence of CGRP and NPY suggests the involvement of these peptides in the regulation of the umbilical and placental circulation.

A demonstraçäo de fibras nervosas do funículo umbilical humano com método imunohistoquímico / Demonstration of nerve fibers in the human umbilical cord with immunohistochemical method

Propusemo-nos a estudar a presença de elementos nervosos em segmentos justafetais de funículos umbilicais humanos. O método usado foi o da peroxidase-antiperoxidase (PAP), com o intuito de detectar a enolase neurônio-específlca, enzima tracitoplasmática dos elementos nervosos, envolvida na via glicolítica; como controle, a mesma metodologia foi aplicada em segmentos de artéria tibial posterior humana. Nos dez funículos umbilicais usados foram sempre evidenciados elementos nervosos, tanto nas suas artérias como na veia, notadamente na respectiva adventícia e parte externa da túnica muscular. No restante da parede vascular (parte interna da túnica muscular e túnica íntima) nao logramos distinguir elementos nervosos. A presença de feixes nervosos na periferia dos vasos, gradualmente mais delicados para o interior da parede vascular, sugere que estes elementos vao terminando nesta direçao.

Prostacyclin producing activity of human umbilical blood vessels in adrenergic innervated and non-innervated portions.

The present experiment was performed in order to clarify the significance of prostacyclin (PGI2) in the regulation of human umbilical blood flow. Distribution of adrenergic nerve fibers in umbilical cord was examined by means of a modification of the glyoxylic acid fluorescence histochemical technique. PGI2 producing activity in various portions of umbilical blood vessels was measured by platelet bioassay. Adrenergic nerve fibers were observed only in the region surrounding umbilical arteries at the fetal end of the cord. PGI2 producing activity of umbilical arteries was significantly lower in the innervated region than in the non-innervated region. There were no significant regional differences in umbilical vein which has no adrenergic innervation. The relationship between vascular PGI2 producing activity and adrenergic innervation, and the significance of PGI2 in the regulation of human umbilical blood flow are discussed.

Lack of innervation of human umbilical cord. An immunohistological and histochemical study.

Using a panel of antibodies (monoclonal as well as polyclonal) to nerves, nerve tissue was not identified within the umbilical cord.

[Confirmation of the presence of adrenergic fibers in human umbilical cord by electron microscopy].

1) In order to visualize biogenic catecholamine, the FAGLUPAGAS method, a new modification of the glyoxylic acid method, was used. Catecholaminergic fibers were observed chiefly in the intraarterial and surrounding region of arteries within Wharton's jelly. Periarterial plexus formation was also observed only in part of the umbilical cord near the umbilical ring. 2) Because first of all we had succeeded in detecting longitudinally running catecholaminergic fibers forming a periarterial plexus, we were able to prepare ultrathin sections exactly parallel to such fibers, and succeeded in confirming the presence of adrenergic fibers in human umbilical cord by electron microscopy.

[Nervous system of the extraembryonic organs of the white rat fetus]. / Nervnyi apparat vnezarodyshevykh organov plodov belykh krys.

Nervous apparatuses of the fetal membranes have been studied in white rats on the 18th-19th days of embryogenesis. Experimental hypoxia, novocaine and potassium chloride solutions effect ensure better revealing of the nervous system elements. At supravital staining with mythelene blue and at impregnation with silver nitrate, nervous fibers are revealed in the distal part of the umbilical cord and in the placental chorional plate. In the labyrinth part of the placenta certain nervous terminals are revealed. In the amnion certain nervous fibers and terminals are found both in the connective tissue and in the epithelium. On the omphaloplacenta vessels numerous nervous apparatuses are detected. A conclusion is made that at the end of embryogenesis the fetal membranes in the white rats are abundantly innervated. This demonstrates nervous regulation of the fetal membranes functions and of interrelationships of the fetus and the maternal organism.

Some aspects of the innervation of the abdominal and pelvic organs in the human female fetus.

The autonomic abdominal and pelvic nerve plexuses of the human female fetus, were studied by an in toto acetylcholinesterase method in order to obtain data on innervation of the ovaries, uterus, ureter and umbilical cord. The results of this study indicate that in the human fetus there is no anatomical evidence for the concept of a distinct regional nervous supply towards the organs of the abdomen and the pelvis. The ureteric nerve plexus contains small ganglia and the input for this plexus is found along the entire ureter. In the umbilical cord nerve plexuses were found along the blood vessels and urachus up to 30 mm from the umbilicus. The innervation of the skin does not continue in the superficial layer of the umbilical cord.

[The question of the innervation of the umbilical cord]. / Studie zur Frage der Innervation der Nabelschnur.

By supravital Methylenbluestaining a dense network of vegetative nerve fibres is demonstrated in the adventitia arround the arteries of the umbilical cord. Some of these nerve fibres are of cholinergic nature.

Neurohistochemical evidence supporting an absence of adrenergic and cholinergic innervation in the human placenta and umbilical cord.

Neurohistochemical techniques were used to determine the distribution of adrenergic and cholinergic nerves in the human placenta and the umbilical cord adjacent to the chorion. These morphologic studies demonstrate the absence of neural elements in these sites. The significance of these findings to the placental innervation controversy is discussed.

The innervation of the umbilical cord of the rat. A histochemical study.

The umbilical cords of 21 days old rat foetuses were investigated using histochemical methods for acetylcholinesterase and catecholamines. An AChE positive nerve plexus is situated only around the vitelline vessels. At regular intervals the bundles of this plexus exhibit small ganglia. These ganglia are made up of nerve cells, which are AChE positive and show formaldehyde induced fluorescence, thus indicating an adrenergic nature of these cells. No innervation could be found in the allantoic part of the umbilical cord.