Cocaine and Amphetamine Regulated Transcript (CART) Expression Changes in the Stomach Wall Affected by Experimentally Induced Gastric Ulcerations

Cocaine- and amphetamine-regulated transcript (CART) is a peptide suggested to play a role in gastrointestinal tract tissue reaction to pathology. Gastric ulceration is a common disorder affecting huge number of people, and additionally, it contributes to the loss of pig livestock production. Importantly, ulceration as a focal disruption affecting deeper layers of the stomach wall differs from other gastrointestinal pathologies and should be studied individually. The pig’s gastrointestinal tract, due to its many similarities to the human counterpart, provides a valuable experimental model for studying digestive system pathologies. To date, the role of CART in gastric ulceration and the expression of the gene encoding CART in porcine gastrointestinal tube are completely unknown. Therefore, we aimed to verify the changes in the CART expression by Q-PCR (gene encoding CART in the tissue) and double immunofluorescence staining combined with confocal microscopy (CART immunofluorescence in enteric nervous system) in the porcine stomach tissues adjacent to gastric ulcerations. Surprisingly, we found that gastric ulcer caused a significant decrease in the expression of CART-encoding gene and huge reduction in the percentage of CART-immunofluorescent myenteric perikarya and neuronal fibers located within the circular muscle layer. Our results indicate a unique CART-dependent gastric response to ulcer disease.

Paracervical ganglion in the female pig during prenatal development: Morphology and immunohistochemical characteristics

The present study investigated the development of the paracervical ganglion in 5-, 7- and 10-week-old porcine foetuses using double labelling immunofluorescence method. In 5-week-old foetuses single PGP-positive perikarya were visible only along the mesonephric ducts. They contained DβH or VAChT, and nerve fibres usually were PGP/VAChT-positive. The perikarya were mainly oval. In 7-week-old foetuses, a compact group of PGP-positive neurons (3144±213) was visible on both sides and externally to the uterovaginal canal mesenchyme of paramesonephric ducts. Nerve cell bodies contained only DβH (36.40±1.63%) or VAChT (17.31±1.13%). In the 10-week-old foetuses, the compact group of PGP-positive neurons divided into several large and many small clusters of nerve cells and also became more expanded along the whole uterovaginal canal mesenchyme reaching the initial part of the uterine canal of the paramesonephric duct. The number of neurons located in these neuronal structures increased to 4121±259. Immunohistochemistry revealed that PGP-positive nerve cell bodies contained DβH (40.26±0,73%) and VAChT (30.73±1.34%) and were also immunoreactive for NPY (33.24±1,27%), SOM (23.6±0,44%) or VIP (22.9±1,13%). Other substances studied (GAL, NOS, CGRP, SP) were not determined at this stage of the development. In this study, for the first time, the morphology of PCG formation in the porcine foetus has been described in three stages of development. Dynamic changes in the number of neurons and their sizes were also noted, as well as the changes in immunochistochemical coding of maturing neurons.

Inferior vagal ganglion galaninergic response to gastric ulcers

Galanin is a neuropeptide widely expressed in central and peripheral nerves and is known to be engaged in neuronal responses to pathological changes. Stomach ulcerations are one of the most common gastrointestinal disorders. Impaired stomach function in peptic ulcer disease suggests changes in autonomic nerve reflexes controlled by the inferior vagal ganglion, resulting in stomach dysfunction. In this paper, changes in the galaninergic response of inferior vagal neurons to gastric ulceration in a pig model of the disease were analyzed based on the authors' previous studies. The study was performed on 24 animals (12 control and 12 experimental). Gastric ulcers were induced by submucosal injections of 40% acetic acid solution into stomach submucosa and bilateral inferior vagal ganglia were collected one week afterwards. The number of galanin-immunoreactive perikarya in each ganglion was counted to determine fold-changes between both groups of animals and Q-PCR was applied to verify the changes in relative expression level of mRNA encoding both galanin and its receptor subtypes: GalR1, GalR2, GalR3. The results revealed a 2.72-fold increase in the number of galanin-immunoreactive perikarya compared with the controls. Q-PCR revealed that all studied genes were expressed in examined ganglia in both groups of animals. Statistical analysis revealed a 4.63-fold increase in galanin and a 1.45-fold increase in GalR3 mRNA as compared with the controls. No differences were observed between the groups for GalR1 or GalR2. The current study confirmed changes in the galaninergic inferior vagal ganglion response to stomach ulcerations and demonstrated, for the first time, the expression of mRNA encoding all galanin receptor subtypes in the porcine inferior vagal ganglia.

Nerve structures of the heart and their immunohistochemical characterization in 10-week-old porcine foetuses

The aim of the present study was to investigate the distribution of neuronal perikarya and nerve fibres and their chemical coding in the heart of 10-week-old porcine foetuses. The foetuses, obtained from a local slaughterhouse, were fixed by immersion in 4% buffered (pH 7.4) paraformaldehyde. Cryostat sections of the hearts were processed for single- or double-labelling immunofluorescence methods using antibodies against protein gene product (PGP) dopamine beta-hydroxylase (DβH), acetylcholine vesicular transporter (VAChT) and calcitonin gene-related peptide (CGRP). Numerous clusters of the PGP-positive nerve cells were observed throughout the heart wall. The majority of the clusters were found beneath the epicardium around the root of the aorta, pulmonary trunk and main veins. Some single PGP-positive neurons or small clusters of nerve cells were observed in the epicardium of heart atria and ventricles. The richest network of PGP-positive nerve fibres was observed in the base of the heart near the main cardiac blood vessel openings. Many bundles of PGP-positive nerve fibres were observed throughout the four cardiac chambers. Double-immunohistochemical staining revealed that the majority of the neurons contained immunoreactivity to VAChT, some of them stained for CGRP and the single neuronal somata were DβH-positive. The nerve fibres supplying the heart expressed immunoreactivity to DβH, VAChT or CGRP. The distribution and neurochemical coding of the nerve structures in ten-week-old foetuses are different from those observed in the hearts of juvenile pigs.

Distribution and chemical coding of urinary bladder apex-projecting neurons in aorticorenal and testicular ganglia of the male pig

Combined retrograde tracing and double-labelling immunofluorescence were used to investigate the distribution and chemical coding of neurons in aorticoerenal (ARG) and testicular (TG) ganglia supplying the urinary bladder apex (UBA) in the juvenile male pig (n=4, 12 kg. body weight). Retrograde fluorescent tracer Fast Blue (FB) was injected into the wall of the bladder apex under pentobarbital anesthesia. After three weeks all the pigs were deeply anesthetized and transcardially perfused with 4% buffered paraformaldehyde. TG and ARG were collected and processed for double-labelling immunofluorescence. The presence of tyrosine hydroxylase (TH) or dopamine beta-hydroxylase (DBH), neuropeptide Y (NPY), somatostatin (SOM), galanin (GAL), nitric oxide synthase (NOS) and vesicular acetylcholine transporter (VAChT) were investigated. The cryostat sections were examined with a Zeiss LSM 710 confocal microscope equipped with adequate filter blocks. The TG and ARG were found to contain many FB-positive neurons projecting to the UBA (UBA-PN). The UBA-PN were distributed in both TG and ARG. The majority were found in the left ganglia, mostly in TG. Immunohistochemistry disclosed that the vast majority of UBA-PN were noradrenergic (TH- and/or DBH-positive). Many noradrenergic neurons also contained immunoreactivity to NPY, SOM or GAL. Most of the UBA-PN were supplied with varicose VAChT-, or NOS- IR (immunoreactive) nerve fibres. This study has revealed a relatively large population of differently coded ARG and TG neurons projecting to the porcine urinary bladder. As judged from their neurochemical organization these nerve cells constitute an important element of the complex neuro-endocrine system involved in the regulation of the porcine urogenital organ function.

Innervation of internal female genital organs in the pig during prenatal development

This study investigated the innervation of internal genital organs in 5-, 7- and 10-week-old female pig foetuses using single and double-labelling immunofluorescence methods. The structure and topography of the organs was examined using a scanning electron microscope (SEM). The investigations revealed differences in the innervation between the three developmental periods. Immunostaining for protein gene product 9.5 (PGP; general neural marker) disclosed solitary nerve fibres in the external part of the gonadal ridge and just outside of the mesenchyme surrounding mesonephric ducts in 5-week-old foetuses. Double-labelling immunohistochemistry revealed that nerve fibres associated with the ridge expressed dopamine β-hydroxylase (DβH; adrenergic marker) or vesicular acetylcholine transporter (VAChT; cholinergic marker). In 7-week-old foetuses, the PGP-positive nerve terminals were absent from the gonad but some of them ran outside and along, and sometimes penetrated into the mesenchyme surrounding the tubal and uterine segments of the paramesonephric ducts and uterovaginal canal. Few axons penetrated into the mesenchyme. DβH-positive fibres were found in single nerve strands or bundles distributed at the edge of the mesenchyme. VAChT-positive nerve terminals formed delicate bundles located at the edge of the mesenchyme, and the single nerves penetrated into the mesenchyme. DβH was also expressed by neurons which formed cell clusters comprising also DβH- or VAChT-positive nerve fibres. In 10-week-old foetuses, PGP-positive nerve fibres were still absent from the ovary but some were distributed in the mesenchyme associated with the uterovaginal canal and uterine and a tubal segment of the paramesonephric ducts, respectively. DβH- or VAChT-positive nerve fibres were distributed at the periphery of the mesenchyme associated with the uterovaginal canal. Some DβH- and many VAChT-positive nerve fibres were evenly distributed throughout the mesenchyme. The clusters of nerve cells comprised DβH-positive perikarya and DβH- or VAChT-positive nerve fibres. The investigations revealed no DβH/VAChT-positive nerve fibres or neurons as well as no nerve structures stained for calcitonin gene-related peptide and/or substance P (sensory markers) associated with the genital organs in the studied prenatal periods.

Enteric nervous system in the European beaver (Castor fiber) pylorus - an immunohistochemical study

European beaver (Castor fiber), the largest rodent species inhabiting a wide area of Eurasia, feeds mainly on dry parts of plants, bark or wood. Such kind of nourishment needs to be properly digested in each part of the gastrointestinal tract. The time of stomach digestion, which directly influences all the following steps of the digestion process, is precisely controlled by the pylorus and its innervation. However, virtually no data is available on the organization of the enteric nervous system in most of the wild animal species, including beavers. On the other hand, a pecu- liar diet consumed by beavers, suggests that the arrangement of their stomach intramural nerve elements can be atypical. Therefore, the present study investigated the distribution and chemical coding of neurons and nerve fibers in the pylorus of the European beaver. The experiment was performed on stomachs obtained from a group of 6 beavers caught in Northeastern region of Poland (due to beaver overpopulation). Pyloric wall tissue cryosections were double immunostained with a mixture of antibodies against pan-neuronal marker PGP 9.5 (to visualize enteric neurons) and ChAT (cholinergic marker), nNOS (nitrergic marker), SP, CGRP, Gal (peptidergic markers). Confocal microscopy analysis revealed that the majority of enteric nerve cells were clustered forming submucosal and myenteric ganglia and all the studied substances were expressed (in various amounts) in these neurons. We conclude, that the anatomical arrangement and chemical coding of intramural nerve elements in the beaver pylorus resemble those found in other mammalian species.

Galaninergic intramural nerve and tissue reaction to antral ulcerations

BACKGROUND

Well-developed galaninergic gastric intramural nerve system is known to regulate multiple stomach functions in physiological and pathological conditions. Stomach ulcer, a disorder commonly occurring in humans and animals, is accompanied by inflammatory reaction. Inflammation can cause intramural neurons to change their neurochemical profile. Galanin and its receptors are involved in inflammation of many organs, however, their direct participation in stomach reaction to ulcer is not known. Therefore, the aim of the study was to investigate adaptive changes in the chemical coding of galaninergic intramural neurons and mRNA expression encoding Gal, GalR1, GalR2, GalR3 receptors in the region of the porcine stomach directly adjacent to the ulcer location.

METHODS

The experiment was performed on 24 pigs, divided into control and experimental groups. In 12 experimental animals, stomach antrum ulcers were experimentally induced by submucosal injection of acetic acid solution. Stomach wall directly adjacent to the ulcer was examined by: (1) double immunohistochemistry-to verify the changes in the number of galaninergic neurons (submucosal, myenteric) and fibers; (2) real-time PCR to verify changes in mRNA expression encoding galanin, GalR1, GalR2, GalR3 receptors.

KEY RESULTS

In the experimental animals, the number of Gal-immunoreactive submucosal perikarya was increased, while the number of galaninergic myenteric neurons and fibers (in all the stomach wall layers) remained unchanged. The expression of mRNA encoding all galanin receptors was increased.

CONCLUSIONS & INTERFERENCES

The results obtained unveiled the participation of galanin and galanin receptors in the stomach tissue response to antral ulcerations.

The Influence of Gastric Antral Ulcerations on the Expression of Galanin and GalR1, GalR2, GalR3 Receptors in the Pylorus with Regard to Gastric Intrinsic Innervation of the Pyloric Sphincter

Gastric antrum ulcerations are common disorders occurring in humans and animals. Such localization of ulcers disturbs the gastric emptying process, which is precisely controlled by the pylorus. Galanin (Gal) and its receptors are commonly accepted to participate in the regulation of inflammatory processes and neuronal plasticity. Their role in the regulation of gastrointestinal motility is also widely described. However, there is lack of data considering antral ulcerations in relation to changes in the expression of Gal and GalR1, GalR2, GalR3 receptors in the pyloric wall tissue and galaninergic intramural innervation of the pylorus. Two groups of pigs were used in the study: healthy gilts and gilts with experimentally induced antral ulcers. By double immunocytochemistry percentages of myenteric and submucosal neurons expressing Gal-immunoreactivity were determined in the pyloric wall tissue and in the population of gastric descending neurons supplying the pyloric sphincter (labelled by retrograde Fast Blue neuronal tracer). The percentage of Gal-immunoreactive neurons increased only in the myenteric plexus of the pyloric wall (from 16.14±2.06% in control to 25.5±2.07% in experimental animals), while no significant differences in other neuronal populations were observed between animals of both groups. Real-Time PCR revealed the increased expression of mRNA encoding Gal and GalR1 receptor in the pyloric wall tissue of the experimental animals, while the expression(s) of GalR2 and GalR3 were not significantly changed. The results obtained suggest the involvement of Gal, GalR1 and galaninergic pyloric myenteric neurons in the response of pyloric wall structures to antral ulcerations.

Immunohistochemical Characterization of Sympathetic Chain Ganglia (SChG) Neurons Supplying the Porcine mammary Gland

The aim of this study was to investigate the chemical coding of mammary gland-projecting SChG neurons using double-labelling immunohistochemistry. Earlier observation showed that after injection of the retrograde tracer fast blue (FB) into the second, right thoracic mamma, FB+ mammary gland-projecting neurons were found in Th1-3, Th9-14 and L1-4 right SChG. The greatest number of FB+ nerve cell bodies was observed in Th10 (approx. 843) and Th11 (approx. 567). Neurons projecting to the last right abdominal mamma were found in L1-4 SChG. The greatest number of FB+ neurons was observed in L2 (approx. 1200). Immunohistochemistry revealed that the vast majority of FB+ mammary-projecting neurons contained immunoreactivities to TH (96.97%) and/or DßH (95.92%). Many TH/DßH-positive neurons stained for SOM (41.5%) or NPY (33.2%), and less numerous nerve cells expressed VIP (16.9%). This observation strongly corresponds to the results of previous studies concerning the immunohistochemical characterization of nerve fibres supplying the porcine mammary gland.

Immunohistochemical characterisation of dorsal root ganglia neurons supplying the porcine mammary gland

The present study investigated the chemical coding of mammary gland-projecting dorsal root ganglia (DRG) neurons using double-labelling immunohistochemistry. Earlier investigations revealed the presence of Fast blue - positive (FB+) neurons in Th9-Th12 DRG after injection of the tracer into the second, right thoracic mamma. Neurons projecting to the last right abdominal mamma were found in L1-L3 DRG. In the present study, the cryostat sections from these ganglia were stained for calcitonin gene-related peptide (CGRP), substance P (SP), nitric oxide synthase (NOS), galanin (GAL) and pituitary adenylate cyclase activating polypeptide (PACAP). Immunohistochemistry revealed that the vast majority of FB+ mammary gland-projecting neurons contained immunoreactivity to CGRP (68.87±0.7%), SP (63.4±0.9%), NOS (32.47±0.9%), GAL (16.28±0.8%) and less numerous nerve cells stained for PACAP (5.87±0.5%). The present results largely correspond with findings dealing with immunohistochemical characterization of nerve fibres supplying porcine mammary gland structures described earlier.

Evidence for coexistence of choline acetyltransferase (ChAT)- and calcitonin gene-related peptide (CGRP)-immunoreactivity in the thoracolumbar and sacral spinal cord neurons of the pig

Previous immunocytochemical studies provided conflicting data concerning occurrence of the CGRP-immunoreactive neuronal cell bodies in the porcine spinal cord. In the present study, we have investigated expression of the CGRP and its possible coexpression with ChAT in the gray matter of the thoracic, lumbar and sacral spinal cord of the pig. Our study revealed a large number of CGRP-immunoreactive cells in the motor nucleus of the ventral horn, and less and singe perikarya intermediolateral and intermediomedial nuclei, respectively. Double staining immunocytochemistry, depending on the cross-section level, disclosed the highest ChAT/CGRP colocalization subsequently in the motor nucleus of the ventral horn, then in the intermediolateral and intermediomedial nucleus. Our data provide morphological evidence confirming expression of CGRP in the porcine spinal nuclei while its coexpression in cholinergic neurons suggests that CGRP may play a role in modulation of the spinal cholinergic transmission.

The distribution and chemical coding of intramural neurons supplying the porcine stomach - the study on normal pigs and on animals suffering from swine dysentery

The present study was designed to investigate the expression of biologically active substances by intramural neurons supplying the stomach in normal (control) pigs and in pigs suffering from dysentery. Eight juvenile female pigs were used. Both dysenteric (n = 4; inoculated with Brachyspira hyodysenteriae) and control (n = 4) animals were deeply anaesthetized, transcardially perfused with buffered paraformalehyde, and tissue samples comprising all layers of the wall of the ventricular fundus were collected. The cryostat sections were processed for double-labelling immunofluorescence to study the distribution of the intramural nerve structures (visualized with antibodies against protein gene-product 9.5) and their chemical coding using antibodies against vesicular acetylcholine (ACh) transporter (VAChT), nitric oxide synthase (NOS), galanin (GAL), vasoactive intestinal polypeptide (VIP), somatostatin (SOM), Leu(5)-enkephalin (LENK), substance P (SP) and calcitonin gene-related peptide (CGRP). In both inner and outer submucosal plexuses of the control pigs, the majority of neurons were SP (55% and 58%, respectively)- or VAChT (54%)-positive. Many neurons stained also for CGRP (43 and 45%) or GAL (20% and 18%) and solitary perikarya were NOS-, SOM- or VIP-positive. The myenteric plexus neurons stained for NOS (20%), VAChT (15%), GAL (10%), VIP (7%), SP (6%) or CGRP (solitary neurons), but they were SOM-negative. No intramural neurons immunoreactive to LENK were found. The most remarkable difference in the chemical coding of enteric neurons between the control and dysenteric pigs was a very increased number of GAL- and VAChT-positive nerve cells (up to 61% and 85%, respectively) in submucosal plexuses of the infected animals. The present results suggest that GAL and ACh have a specific role in local neural circuits of the inflamed porcine stomach in the course of swine dysentery.

Distribution of Neurons Supplying the Porcine Mammary Gland

The distribution of neurons projecting to the mammary gland was investigated by using the retrograde tracing method in juvenile pigs (n = 12). Fluorescent retrograde tracer Fast Blue (FB) was injected into the nipple (n = 3) or parenchyma (n = 3) of the second, right thoracic mamma or into the nipple (n = 3) and parenchyma (n = 3) of the last, right abdominal mamma. FB-positive (FB+) mammary gland-projecting neurons were found in some right dorsal root ganglia (DRG) and sympathetic chain ganglia (SChG) only. After injection of the tracer into the second, right thoracic mamma, FB+ neurons were observed in Th9-Th12 DRG but most of them were located in Th11 and Th12 ganglia. As concerns SChG, FB+ neurons were found in Th1-Th4, Th7-Th14 and L1-L4 ganglia. The vast majority of them were located in Th10 and Th11 SChG, which appeared to be the main sources of efferent innervation of this mamma. Neurons projecting to the last right abdominal mamma were found in L1-L3 DRG and L1-L4 SChG but most of them were located in L1-L2 ganglia and L1-L2 ganglia, respectively. This study for the first time has disclosed the localization of neurons supplying the mammary gland in larger domestic animal species, the pig, by using the retrograde tracing method.

The distribution and chemical coding of neurons in the celiac-superior mesenteric ganglion complex supplying the normal and inflamed ileum in the pig

The present study investigated the chemical coding of neurons in the celiac-superior mesenteric ganglion complex supplying the normal (n=4) and inflamed (n=4) ileum (chemically-induced inflammation) in juvenile pigs using retrograde tracing combined with immunohistochemistry. Ileum-projecting neurons (IPN) were predominantly distributed in the left and right superior mesenteric pools of the ganglion. The majority of them were adrenergic (tyrosine hydroxylase-positive) and also contained neuropeptide Y, somatostatin or galanin. No clear-cut differences in the distribution and chemical coding of IPN were found between normal and inflamed pigs. However, in the inflamed group, the density of peptidergic, IPN-associated nerve fibres was higher than that found in the control group.

Vasoactive intestinal polypeptide (VIP)--immunoreactive nerve fibres in the mammary gland of the pig

Immunohistochemical studies have been performed to investigate the coexistence of VIP with dopamine-beta-hydroxylase (D(beta)H), vesicular acetylcholine transporter (VAChT), somatostatin (SOM) or neuropeptyd Y (NPY) within nerve fibres supplying the immature mammary gland in the pig. Generally, a moderate number of the VIP-immunoreactive (VIP-IR) nerve fibres were located in the nipple and parenchyma of the gland. VIP-IR fibres surrounded smooth muscle cells (SMC), blood vessels (BV) and lactiferous ducts (LD). Double-labelling immunohistochemistry revealed that some of VIP-IR nerve fibres also contained immunoreactivity to D(beta)H. VIP/D(beta)H-IR nerves were associated with BV and SMC and single fibres were observed around the LD in both nipple and parenchyma of the gland. VIP/VAChT-IR nerve fibres were not observed. The majority of VIP-IR fibres associated with SMC were also SOM-IR. Less numerous VIP/SOM-IR fibres supplied the BV and were located around the LD of the gland. A small number of VIP-IR nerves also displayed immunoreactivity to NPY. VIP/NPY-IR nerve fibres supplied the BV of the gland.

Noradrenergic and peptidergic innervation of the mammary gland in the immature pig

The presence and pattern of coexistence of some biologically active substances in nerve fibres supplying the mammary gland in the immature pig were studied using immunohistochemical methods. The substances studied included: protein gene product 9.5 (PGP), tyrosine hydroxylase (TH), somatostatin (SOM), neuropeptide Y (NPY), galanin (GAL), calcitonin gene-related peptide (CGRP) and substance P (SP). The mammary gland was found to be richly supplied by PGP-immunoreactive (PGP-IR) nerve fibres that surrounded blood vessels, bundles of smooth muscle cells and lactiferous ducts. The vast majority of these nerves also displayed immunoreactivity to TH. Immunoreactivity to SOM was observed in a moderate number of nerve fibres which were associated with smooth muscles of the nipple and blood vessels. Immunoreactivity to NPY occurred in many nerve fibres associated with blood vessels and in single nerves supplying smooth muscle cells. Solitary GAL-IR axons supplied mostly blood vessels. Many CGRP-IR nerve fibres were associated with both blood vessels and smooth muscles. SP-IR nerve fibres richly supplied blood vessels only. The colocalization study revealed that SOM, NPY and GAL partly colocalized with TH in nerve fibres supplying the porcine mammary gland.

Adrenergic and cholinergic innervation of the mammary gland in the pig

Adrenergic and acetylcholinesterase-positive (AChE-positive) innervation of the mammary gland in the sexually immature and mature pigs was studied using histochemical methods. Upon examining the adrenergic and cholinergic innervation, the adrenergic innervation was found to be much more developed. The majority of both sub-populations of the nerve fibres studied was localized in the subcutaneous tissue of the mammary gland. Adrenergic and AChE-positive nerve fibres also supplied structures of the nipple (subcutaneous tissue, blood vessels, smooth muscles fibres) and glandular tissue (blood vessels, lactiferous ducts). The glandular tissue contained the smallest number of adrenergic and AChE-positive nerve fibres. No distinct differences were observed in the adrenergic and AChE-positive innervation of the porcine mammary gland between the juvenile and non-pregnant adult animals.

Distribution of ganglionic sympathetic neurons supplying the subcutaneous, perirenal and mesentery fat tissue depots in the pig

Previous morphological studies revealed that the adipose tissue is innervated by adrenergic nerve fibers. Furthermore, physiological studies showed that the metabolism of adipose tissue is controlled by the adrenergic component of the nervous system. However, nothing is known on the sources of innervation of different fat tissue depots. Therefore, we decided to study the distribution of ganglionic sympathetic neurons innervating adipose tissue in the pig by means of a retrograde tracing method. We used 9 male and 9 female pigs of approximately 50 kg body weight. The retrograde tracer, Fast Blue (FB), was injected into the subcutaneous, perirenal and mesentery fat tissue depots. Results of the present study showed that numerous centers of the sympathetic nervous system innervate adipose tissue in the pig. FB+ neurons projecting to the subcutaneous fat tissue were placed in the thoraco-lumbar region of the sympathetic chain ganglia (SChG). However, neurons supplying perirenal and mesentery fat tissue depots were found in both the SChG and prevertebral ganglia (PVG). We conclude that different adipose tissue depots (subcutaneous, perirenal and mesentery) have different sources of innervation and that there is no significant difference in the distribution of neurons innervating adipose tissue in male and female pigs.

Distribution of efferent neurones innervating the oviduct in the pig

This study was aimed, by means of the retrograde tracing technique, at disclosing the distribution of efferent neurones innervating the porcine oviduct. The fluorescent retrograde tracer Fast Blue was injected into the wall of the right oviduct in six juvenile pigs during laparotomy performed under anaesthesia. After a recovery period of 3 weeks the animals were reanaesthetised, perfused with 4% buffered paraformaldehyde (pH 7.4) and different ganglia, thought to be potent sources of the efferent innervation, were collected. The occurrence and distribution of Fast Blue-positive neurones were studied in the sympathetic chain and prevertebral ganglia, including the coeliac-superior mesenteric ganglion complex, adrenal ganglion, aorticorenal ganglion, ovarian ganglion and inferior mesenteric ganglion. The labelled neurones were found only in the right, ipsilateral ganglia. The largest number of Fast Blue-positive neurones was found in the inferior mesenteric ganglion, ovarian ganglion and in the coeliac-superior mesenteric ganglion complex. In the inferior mesenteric ganglion, the Fast Blue-positive neurones showed a tendency to gather in the dorso-cranial and the dorso-caudal region of the ganglion, forming two discrete "oviductal centres". The aortico-renal and adrenal ganglion contained a smaller population of Fast Blue-positive nerve cell bodies. The smallest number of Fast Blue-positive neurones was found in the sympathetic chain ganglia (T14-L5). The localisation of Fast Blue-positive neurones in the sympathetic chain ganglia and prevertebral ganglia suggests that these nerve structures play a fundamental role in the efferent innervation of the porcine oviduct.