Prolonged acetylsalicylic-acid-supplementation-induced gastritis affects the chemical coding of the stomach innervating vagal efferent neurons in the porcine dorsal motor vagal nucleus (DMX)

Glyphosate-induced changes in the expression of galanin and GALR1, GALR2 and GALR3 receptors in the porcine small intestine wall

Glyphosate is the active ingredient of glyphosate-based herbicides and the most commonly used pesticide in the world. The goal of the present study was to verify whether low doses of glyphosate (equivalent to the environmental exposure) evoke changes in galanin expression in intramural neurons in the small intestine in pigs and to quantitatively determine changes in the level of galanin receptor encoding mRNA (GALR1, GALR2, GALR3) in the small intestine wall. The experiment was conducted on 15 sexually immature gilts divided into three study groups: control (C)-animals receiving empty gelatin capsules; experimental 1 (G1)-animals receiving a low dose of glyphosate (0.05 mg/kg b.w./day); experimental 2 (G2)-animals receiving a higher dose of glyphosate (0.5 mg/kg b.w./day) orally in gelatine capsules for 28 days. Glyphosate ingestion led to an increase in the number of GAL-like immunoreactive intramural neurons in the porcine small intestine. The results of RT-PCR showed a significant increase in the expression of mRNA, which encodes the GAL-receptors in the ileum, a decreased expression in the duodenum and no significant changes in the jejunum. Additionally, intoxication with glyphosate increased the expression of SOD2-encoding mRNA in the duodenum and decreased it in the jejunum and ileum, but it did not affect SOD1 expression. The results suggest that it may be a consequence of the cytotoxic and/or neurotoxic properties of glyphosate and/or its ability to induce oxidative stress.

Uterine Inflammation Changes the Expression of Cholinergic Neurotransmitters and Decreases the Population of AChE-Positive, Uterus-Innervating Neurons in the Paracervical Ganglion of Sexually Mature Gilts

Simple Summary

Endometritis, both with non-infectious and infectious backgrounds, is one of the most prevalent pathological states among domestic animals. In animals, it generates severe economic problems, including lowered reproductive indices and rising medical treatment costs, and in women, it might lead to severe fertility impairment. In order to determine how the autonomic nervous system responds to such a pathological state, an experimental group of pigs were treated with Escherichia coli injection into the uterine horns, and several ganglions responsible for innervation of this organ were examined, including the paracervical ganglion located on both sides of the broad ligament of the uterus. The results clearly showed a strong impact of the inflammation on the chemical coding of neurons, some even synthesizing neurotransmitters de novo such as the GAL-expressing perikarya. Additionally, applied injections decreased the number of parasympathetic, acetylcholinesterase-expressing neurons implying the importance of the cholinergic population to keep the inflammation under control. The obtained data serve as a basis for the future implementation of modern treatment and enhancements in animal breeding.

Abstract

The focus of this study was based on examining the impact of endometritis on the chemical coding of the paracervical ganglion (PCG) perikaryal populations supplying pig uterus. Four weeks after the injection of Fast Blue retrograde tracer into uterine horns, either the Escherichia coli (E. coli) suspension or saline solution was applied to both horns. Laparotomy treatment was performed for the control group. Uterine cervices containing PCG were extracted on the eighth day after previous treatments. Subsequent macroscopic and histopathologic examinations acknowledged the severe form of acute endometritis in the E. coli-treated gilts, whereas double-labeling immunofluorescence procedures allowed changes to be analyzed in the PCG perikaryal populations coded with vesicular acetylcholine transporter (VAChT) and/or somatostatin (SOM), vasoactive intestinal polypeptide (VIP), a neuronal isoform of nitric oxide synthase (nNOS), galanin (GAL). The acetylcholinesterase (AChE) detection method was used to check for the presence and changes in the expression of this enzyme and further confirm the presence of cholinergic perikarya in PCG. Treatment with E. coli resulted in an increase in VAChT+/VIP+, VAChT+/VIP−, VAChT+/SOM+, VAChT+/SOM−, VAChT+/GAL− and VAChT+/nNOS− PCG uterine perikarya. An additional increase was noted in the non-cholinergic VIP-, SOM- and nNOS-immunopositive populations, as well as a decrease in the number of cholinergic nNOS-positive perikarya. Moreover, the population of cholinergic GAL-expressing perikarya that appeared in the E. coli-injected gilts and E. coli injections lowered the number of AChE-positive perikarya. The neurochemical characteristics of the cholinergic uterine perikarya of the PCG were altered and influenced by the pathological state (inflammation of the uterus). These results may indicate the additional influence of such a state on the functioning of this organ.

Neurochemical Plasticity of nNOS-, VIP- and CART-Immunoreactive Neurons Following Prolonged Acetylsalicylic Acid Supplementation in the Porcine Jejunum

Aspirin, also known as acetylsalicylic acid (ASA), is a commonly used anti-inflammatory drug that has analgesic and antipyretic properties. The side effects are well known, however, knowledge concerning its influence on gastric and intestinal innervation is limited. The enteric nervous system (ENS) innervates the whole gastrointestinal tract (GIT) and is comprised of more than one hundred million neurons. The capacity of neurons to adapt to microenvironmental influences, termed as an enteric neuronal plasticity, is an essential adaptive response to various pathological stimuli. Therefore, the goal of the present study was to determine the influence of prolonged ASA supplementation on the immunolocalization of neuronal nitric oxide synthase (nNOS), vasoactive intestinal peptide (VIP) and cocaine- and amphetamine- regulated transcript peptide (CART) in the porcine jejunum. The experiment was performed on 8 Pietrain × Duroc immature gilts. Using routine double-labelling immunofluorescence, we revealed that the ENS nerve cells underwent adaptive changes in response to the induced inflammation, which was manifested by upregulated or downregulated expression of the studied neurotransmitters. Our results suggest the participation of nNOS, VIP and CART in the development of inflammation and may form the basis for further neuro-gastroenterological research.

Somatostatin as an Active Substance in the Mammalian Enteric Nervous System

Somatostatin (SOM) is an active substance which most commonly occurs in endocrine cells, as well as in the central and peripheral nervous system. One of the parts of the nervous system where the presence of SOM has been confirmed is the enteric nervous system (ENS), located in the wall of the gastrointestinal (GI) tract. It regulates most of the functions of the stomach and intestine and it is characterized by complex organization and a high degree of independence from the central nervous system. SOM has been described in the ENS of numerous mammal species and its main functions in the GI tract are connected with the inhibition of the intestinal motility and secretory activity. Moreover, SOM participates in sensory and pain stimuli conduction, modulation of the release of other neuronal factors, and regulation of blood flow in the intestinal vessels. This peptide is also involved in the pathological processes in the GI tract and is known as an anti-inflammatory agent. This paper, which focuses primarily on the distribution of SOM in the ENS and extrinsic intestinal innervation in various mammalian species, is a review of studies concerning this issue published from 1973 to the present.

Participation of acetylcholine and its receptors in the contractility of inflamed porcine uterus

This study analyzed the effect of inflammation on acetylcholine (ACh)-induced muscarinic receptors (MR)2 and MR3 conducted contractility of the porcine uterus. On Day 3 of the estrous cycle, either E.coli suspension (E.coli group) or saline (SAL group) was injected into uterine horns or laparotomy was performed (CON group). Eight days later, infected gilts developed severe acute endometritis. Compared to the period before ACh treatment, ACh (10^-5 M) increased the tension in myometrium (MYO) and endometrium/myometrium (ENDO/MYO) of the CON group (P < 0.01) and in ENDO/MYO of the SAL group (P < 0.01), the amplitude in strips of the CON (P < 0.05) and SAL (MYO: P < 0.05, ENDO/MYO: P < 0.001) groups and the frequency in strips of the CON (MYO: P < 0.01, ENDO/MYO: P < 0.001) and SAL (P < 0.01) groups. In the E.coli group, ACh (10^-5 M) reduced the amplitude in MYO (P < 0.05) and ENDO/MYO (P < 0.001), increased the frequency in MYO (P < 0.01) and ENDO/MYO (P < 0.001) and did not change (P > 0.05) the tension. ACh (10^-5 M) in ENDO/MYO of the E.coli group, reduced the tension compared to the CON group (P < 0.05) and the amplitude compared to other groups (P < 0.001), while increased the frequency in relation to the SAL group (P < 0.05). MR2 antagonist (AF-DX 44 116) and ACh (10^-5 M) reduced (by 16.92%, P < 0.01) the tension in MYO of the CON group and increased (P < 0.01) it in the E.coli group compared to the period before antagonist and ACh addition. In MYO of the SAL group, the tension was increased (P < 0.01) in response to MR3 antagonist (4-DAMP) and ACh (10^-7, 10^-6 M). In the E.coli group, these substances did not change (P > 0.05) the tension, but it was lower (P < 0.001) in MYO (ACh: 10^-7 M) and ENDO/MYO (ACh: 10^-5 M) than in the SAL group. MR2 or MR3 antagonists and ACh (10^-5 M) increased (P < 0.05-0.001) the amplitude in strips of the CON and SAL groups and reduced it in the E.coli group (P < 0.001) compared to the period before antagonists and ACh use. This parameter in the E.coli group was lower (P < 0.001) after using MR2 or MR3 antagonists and ACh (10^-6, 10^-5 M) than in other groups. Both antagonists and ACh (10^-5 M) reduced the frequency in the CON, SAL (P < 0.05) and E.coli (MR2 antagonist: P < 0.01, MR3 antagonist: P < 0.05) groups compared to period before antagonists and ACh addition. Data show that ACh reduces the contractility of the inflamed porcine uterus by MR2 and MR3, which suggests that pharmacological modulation of these receptors can be used to raise the contractility of an inflamed uterus.

Presence and Effects of Pituitary Adenylate Cyclase Activating Polypeptide Under Physiological and Pathological Conditions in the Stomach

Pituitary adenylate cyclase activating polypeptide (PACAP) is a multifunctional neuropeptide with widespread occurrence throughout the body including the gastrointestinal system. In the small and large intestine, effects of PACAP on cell proliferation, secretion, motility, gut immunology and blood flow, as well as its importance in bowel inflammatory reactions and cancer development have been shown and reviewed earlier. However, no current review is available on the actions of PACAP in the stomach in spite of numerous data published on the gastric presence and actions of the peptide. Therefore, the aim of the present review is to summarize currently available data on the distribution and effects of PACAP in the stomach. We review data on the localization of PACAP and its receptors in the stomach wall of various mammalian and non-mammalian species, we then give an overview on PACAP's effects on secretion of gastric acid and various hormones. Effects on cell proliferation, differentiation, blood flow and gastric motility are also reviewed. Finally, we outline PACAP's involvement and changes in various human pathological conditions.

Effects of pituitary adenylate cyclase activating polypeptide on small intestinal INT 407 cells

Pituitary adenylate cyclase activating polypeptide (PACAP) is an endogenous neuropeptide having a widespread distribution both in the nervous system and peripheral organs including the gastrointestinal tract. It has been shown to exert actions on intestinal functions, mainly affecting glandular secretion and motility. PACAP has several different effects on cell survival depending on the cell type and the applied stimulus. Its influences on small intestinal epithelial cells are not yet elucidated, therefore the aim of the present study was to investigate the effects of PACAP on intestinal epithelial cells having high turnover (INT 407) against different harmful stimuli, such as oxidative stress, in vitro hypoxia and gamma radiation. We tested the effect of PACAP on proliferation and cell survival using MTT assay. Moreover, various cancer-related factors were evaluated by oncology array. PACAP did not influence the proliferation rate of INT 407 cells. Its cell survival-enhancing effect could be detected against oxidative stress, but not against in vitro hypoxia or gamma irradiation. Clonogenic survival assay was performed to analyze the effect of PACAP on clonogenic potential of cells exposed to gamma radiation. Surprisingly, PACAP enhanced the clone-forming ability decrease induced by irradiation. Western blot analysis of ERK1/2 phosphorylation was performed in order to obtain further information on the molecular background. Our data showed phospho-ERK1/2 suppression of PACAP in irradiated cells. Furthermore, the role of endogenous PACAP against oxidative stress was also investigated performing ADCYAP1 small interfering RNA transfection. We found significant difference in the cell vulnerability between cells undergoing silencing and cells without transfection suggesting the protective role of the endogenously present PACAP against oxidative stress in INT 407 cells. In summary, PACAP seems to be able to exert contradictory effects in INT 407 cells depending on the applied stressor, suggesting its regulatory role in the cellular household.

Cocaine- and Amphetamine-Regulated Transcript (CART ) Peptide in Mammals Gastrointestinal System – A Review

Since its first description over 30 years ago, cocaine- and amphetamine-regulated transcript (CART) peptide has been the subject of many studies. Most of these investigations pertain to occurrence and functions of CART within the central nervous system, where this peptide first of all takes part in regulation of feeding, stress reactions, as well as neuroprotective and neuroregenerative processes. However, in recent years more and more studies concern the presence of CART in the gastrointestinal system. This peptide has been described both in stomach and intestine, as well as in other digestive organs such as pancreas or gallbladder. Particularly much information relates to distribution of CART in the enteric nervous system, which is located within the wall of digestive tract. Other studies have described this peptide in intestinal endocrinal cells. Moreover, it is known that CART can be present in various types of neuronal cells and may co-localize with different types of other neuronal active substances, which play roles of neuromediators and/or neuromodulators. On the other hand precise functions of CART in the gastrointestinal system still remain unknown. It is assumed that this peptide is involved in the regulation of gastrointestinal motility, intestinal blood flow, secretion of intestinal juice, somatostatin and/or insulin, as well as takes part in pathological processes within the gastrointestinal tract. The large number of recent studies concerning the above mentioned problems makes that knowledge about occurrence and functions of CART in the digestive system rather piecemeal and requires clarifying, which is the aim of the present article.

Neuropeptide profile changes in sensory neurones after partial prepyloric resection in pigs

This report details the first identification of the sources of sensory innervation of the porcine stomach prepyloric region. The Fast Blue (FB) retrograde tracing technique detected the sensory prepyloric neurons in the bilateral nodose ganglia (NGs) as well as thoracic dorsal root ganglia (DRGs). Double-labelling immunofluorescence demonstrated expression of substance P (SP), calcitonin gene-related peptide (CGRP), neuronal isoform of nitric oxide synthase (nNOS), vasoactive intestinal polypeptide (VIP) and galanin (GAL) in both NGs and DRGs. Additionally, we found that partial resection of the stomach prepyloric area increased expression of the SP, CGRP, NOS, VIP and GAL in the prepyloric sensory neurons. In the control left NGs, both a higher total number of FB-positive perikarya as well as a higher percentage of the peptides expressing prepyloric neurons were visualized than in the right NGs. However, compared to the control group, prepyloric resection evoked greater increases in peptide expression in the right-side NGs sensory neurons. In the ganglia of this side, the proportion of the SP-IR perikarya increased by approximately 15%, while CGRP-IR increased by 28%, NOS-IR 14%, VIP-IR 43% and GAL-IR 13%. On the opposite left side, the ganglia proportion of the CGRP-IR perikarya increased by approximately 10%, while NOS-IR increased by 3%, VIP-IR 36% and GAL-IR by 2%. The only decrease (by 5%) was observed in the case of SP expression. We also found that 92% of the sensory neurons originated from NGs and 8% from DRGs. Our results indicate that, in the pig, SP, CGRP, NOS, VIP and GAL participate in the vagal sensory transduction from the stomach prepyloric area. Moreover, increased expression of the peptides and neuronal isoform of nitric oxide synthase in the sensory neurons following transection of their peripheral dendrites suggests their possible participation in the neuronal recovery and/or reinnervation process.

Acetylsalicylic acid-induced changes in the chemical coding of extrinsic sensory neurons supplying the prepyloric area of the porcine stomach

Acetylsalicylic acid is a popular drug that is commonly used to treat fever and inflammation, but which can also negativity affect the mucosal layer of the stomach, although knowledge concerning its influence on gastric innervation is very scarce. Thus, the aim of the present study was to study the influence of prolonged acetylsalicylic acid supplementation on the extrinsic primary sensory neurons supplying the porcine stomach prepyloric region. Fast Blue (FB) was injected into the above-mentioned region of the stomach. Acetylsalicylic acid was then given orally to the experimental gilts from the seventh day after FB injection to the 27th day of the experiment. After euthanasia, the nodose ganglia (NG) and dorsal root ganglia (DRG) were collected. Sections of these ganglia were processed for routine double-labelling immunofluorescence technique for substance P (SP), calcitonine gene related peptide (CGRP), galanin (GAL), neuronal isoform of nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP). Under physiological conditions within the nodose ganglia, the percentage of the FB-labeled neurons immunoreactive to particular substances ranged between 17.9 ± 2.7% (VIP-like immunoreactive (LI) neurons in the right NG) and 60.4 ± 1.7% (SP-LI cells within the left NG). Acetylsalicylic acid supplementation caused a considerable increase in the expression of all active substances studied within both left and right NG and the percentage of neurons positive to particular substances fluctuated from 47.2 ± 3.6% (GAL-LI neurons in the right NG) to 67.2 ± 2.0% (cells immunoreactive to SP in the left NG). All studied substances were also observed in DRG neurons supplying the prepyloric region of the stomach, but the number of immunoreactive neurons was too small to conduct a statistical analysis. The obtained results show that ASA may influence chemical coding of the sensory neurons supplying the porcine stomach, but the exact mechanisms of this action still remain unknown.

Endogenous opiates and behavior: 2014

This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants). This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants).

Neurochemical Plasticity of the Coeliac-Superior Mesenteric Ganglion Complex Neurons Projecting to the Prepyloric Area of the Porcine Stomach following Hyperacidity

This study was designed to determine neurochemical properties of the coeliac-superior mesenteric ganglion (CSMG) neurons supplying the prepyloric area of the porcine stomach in physiological state and following experimentally induced hyperacidity. To localize sympathetic neurons innervating the studied area of stomach, the neuronal retrograde tracer Fast Blue (FB) was applied to control animals and hydrochloric acid infusion (HCl) groups. After 23 days, animals of the HCl group were reintroduced into a state of general anesthesia and intragastrically given 5 mL/kg of body weight of 0.25 M aqueous solution of hydrochloric acid. On the 28th day, all animals were sacrificed. The CSMG complexes were then collected and processed for double-labeling immunofluorescence. In the control animals, FB-positive perikarya displayed immunoreactivity to tyrosine hydroxylase (TH), dopamine β-hydroxylase (DβH), neuropeptide Y (NPY), and galanin (GAL). Experimentally induced gastric hyperacidity changed the neurochemical phenotype of the studied neurons. An upregulated expression of GAL and NPY and the de novo synthesis of neuronal nitric oxide synthase (nNOS) and leu5-enkephalin (LENK) as well as downregulated expression of TH and DβH in the stomach-projecting neurons were observed. These findings enrich existing knowledge about the participation of these active substances in adaptive mechanism(s) of the sympathetic neurons during pathological processes within the gastrointestinal tract.

XiangshaLiujunzi decoction alleviates the symptoms of functional dyspepsia by regulating brain-gut axis and production of neuropeptides

Background

Chinese medicine xiangshaliujunzi decoction (XSLJZD) plays a key role in treating functional dyspepsia (FD), a common clinical gastrointestinal disorder. However, the mechanism of this disease is unclear. Brain–gut axis regulates food intake behaviour, and this regulatory mechanism is mediated by neuropeptides. Brain–gut axis impairment and neuropeptide alteration may be the pathological mechanisms of FD, and brain–gut axis regulation may influence the action of medicine.

Methods

In our experiment, the effect of XSLJZD on FD was evaluated in terms of food intake, sucrose preference test and electromyogram. Changes in neuropeptides [ghrelin, cholecystokinin (CCK) and vasoactive intestinal polypeptide (VIP)] were detected through immunohistochemistry, real-time PCR and ELISA.

Results

XSLJZD increased food intake and the percentage of sucrose preference (>75 %). However, the response to gastric detention decreased. Furthermore, XSLJZD increased ghrelin, CCK, VIP proteins and genes in the stomach. XSLJZD also increased ghrelin, CCK and VIP proteins in serum. By contrast, XSLJZD decreased the mRNA expression of these neuropeptides in the hypothalamus.

Conclusions

XSLJZD alleviated the symptoms of FD by upregulating the production of ghrelin, CCK and VIP and by increasing the levels of these neuropeptides in circulation. This finding can help elucidate the mechanism of FD and can provide further insight into the pharmacokinetics of XSLJZD.