Gastric ulcer induced changes in substance P and Nk1, Nk2, Nk3 receptors expression in different stomach localizations with regard to intrinsic neuronal system

Spinal afferent innervation in flat-mounts of the rat stomach: anterograde tracing

The dorsal root ganglia (DRG) project spinal afferent axons to the stomach. However, the distribution and morphology of spinal afferent axons in the stomach have not been well characterized. In this study, we used a combination of state-of-the-art techniques, including anterograde tracer injection into the left DRG T7-T11, avidin-biotin and Cuprolinic Blue labeling, Zeiss M2 Imager, and Neurolucida to characterize spinal afferent axons in flat-mounts of the whole rat stomach muscular wall. We found that spinal afferent axons innervated all regions with a variety of distinct terminal structures innervating different gastric targets: (1) The ganglionic type: some axons formed varicose contacts with individual neurons within myenteric ganglia. (2) The muscle type: most axons ran in parallel with the longitudinal and circular muscles and expressed spherical varicosities. Complex terminal structures were observed within the circular muscle layer. (3) The ganglia-muscle mixed type: some individual varicose axons innervated both myenteric neurons and the circular muscle, exhibiting polymorphic terminal structures. (4) The vascular type: individual varicose axons ran along the blood vessels and occasionally traversed the vessel wall. This work provides a foundation for future topographical anatomical and functional mapping of spinal afferent axon innervation of the stomach under normal and pathophysiological conditions.

Alteration of hippocampal CA2 plasticity and social memory in adult rats impacted by juvenile stress

The hippocampal CA2 region has received greater attention in recent years due to its fundamental role in social memory and hippocampus-dependent memory processing. Unlike entorhinal cortical inputs, the Schaffer collateral inputs to CA2 do not support activity-dependent long-term potentiation (LTP), which serves as the basis for long-term memories. This LTP-resistant zone also expresses genes that restrict plasticity. With the aim of exploring social interaction and sociability in rats that were subjected to juvenile stress, we addressed questions about how the neural circuitry is altered and its effects on social behavior. Although there was induction of LTP in both Schaffer collateral and entorhinal cortical pathways in juvenile-stressed rats, LTP declined in both pathways after 2-3 h. Moreover, exogenous bath application of substance P, a neuropeptide that resulted in slow onset long-lasting potentiation in control animals while it failed to induce LTP in juvenile-stressed rats. Our study reveals that juvenile-stressed rats show behavioral and cellular abnormalities with a long-lasting impact in adulthood.

Topographical distribution and morphology of SP-IR axons in the antrum, pylorus, and duodenum of mice

Substance-P (SP) is a commonly used marker of nociceptive afferent axons, and it plays an important role in a variety of physiological functions including the regulation of motility, gut secretion, and vascular flow. Previously, we found that SP-immunoreactive (SP-IR) axons densely innervated the pyloric antrum of the flat-mount of the mouse whole stomach muscular layer. However, the regional distribution and morphology of SP-IR axons in the submucosa and mucosa were not well documented. In this study, the mouse antrum-pylorus-duodenum (APD) were transversely and longitudinally sectioned. A Zeiss M2 imager was used to scan the serial sections of each APD (each section montage consisted of 50-100 all-in-focus maximal projection images). To determine the detailed structures of SP-IR axons and terminals, we used the confocal microscope to scan the regions of interest. We found that 1) SP-IR axons innervated the muscular, submucosal, and mucosal layers. 2) In the muscular layer, SP-IR varicose axons densely innervated the muscles and formed varicose terminals which encircled myenteric neurons. 3) In the submucosa, SP-IR axons innervated blood vessels and submucosal ganglia and formed a network in Brunner's glands. 4) In the mucosa, SP-IR axons innervated the muscularis mucosae. Some SP-IR axons entered the lamina propria. 5) The muscular layer of the antrum and duodenum showed a higher SP-IR axon density than the pyloric sphincter. 6) SP-IR axons were from extrinsic and intrinsic origins. This work provided a comprehensive view of the distribution and morphology of SP-IR axons in the APD at single cell/axon/varicosity scale. This data will be used to create a 3D scaffold of the SP-IR axon innervation of the APD.

Topographical organization and morphology of substance P (SP)-immunoreactive axons in the whole stomach of mice

Nociceptive afferents innervate the stomach and send signals centrally to the brain and locally to stomach tissues. Nociceptive afferents can be detected with a variety of different markers. In particular, substance P (SP) is a neuropeptide and is one of the most commonly used markers for nociceptive nerves in the somatic and visceral organs. However, the topographical distribution and morphological structure of SP-immunoreactive (SP-IR) axons and terminals in the whole stomach have not yet been fully determined. In this study, we labeled SP-IR axons and terminals in flat mounts of the ventral and dorsal halves of the stomach of mice. Flat-mount stomachs, including the longitudinal and circular muscular layers and the myenteric ganglionic plexus, were processed with SP primary antibody followed by fluorescent secondary antibody and then scanned using confocal microscopy. We found that (1) SP-IR axons and terminals formed an extensive network of fibers in the muscular layers and within the ganglia of the myenteric plexus of the whole stomach. (2) Many axons that ran in parallel with the long axes of the longitudinal and circular muscles were also immunoreactive for the vesicular acetylcholine transporter (VAChT). (3) SP-IR axons formed very dense terminal varicosities encircling individual neurons in the myenteric plexus; many of these were VAChT immunoreactive. (4) The regional density of SP-IR axons and terminals in the muscle and myenteric plexus varied in the following order from high to low: antrum-pylorus, corpus, fundus, and cardia. (5) In only the longitudinal and circular muscles, the regional density of SP-IR axon innervation from high to low were: antrum-pylorus, corpus, cardia, and fundus. (6) The innervation patterns of SP-IR axons and terminals in the ventral and dorsal stomach were comparable. Collectively, our data provide for the first time a map of the distribution and morphology of SP-IR axons and terminals in the whole stomach with single-cell/axon/synapse resolution. This work will establish an anatomical foundation for functional mapping of the SP-IR axon innervation of the stomach and its pathological remodeling in gastrointestinal diseases.

Protective effect of the combination of essential oil from patchouli and tangerine peel against gastric ulcer in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Essential oil (EO) is the main extract of patchouli and tangerine peel with antiinflammatory, antiulcer, and other functions. However, the efficacy and mechanism of the combination of EO from patchouli and tangerine peel against gastric ulcer (GU) are unclear.

AIM OF THE STUDY

This study aims to reveal the protective effect of the combination of EO from patchouli and tangerine peel against GU in rats, as well as explore the optimal ratio and possible mechanism of EO in GU treatment.

MATERIALS AND METHODS

The GU model is executed via water immersion and restraint stress. The repair effect of EO in different proportions on gastric mucosa injury and the effects on serum gastrin (GAS), pepsinogen C (PGC), prostaglandin E2 (PGE2), and 5-hydroxytryptamine in GU rats were observed. The optimal ratio obtained was used in the second part to set different dose groups for further experiment. The effects of the different EO doses on gastric mucosal ulcer formation and gastric acid secretion were evaluated. The morphology of chief and parietal cells were observed via transmission electron microscopy. The contents of GAS, PGC, substance P (SP), cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), cholecystokinin (CCK), PGE2, and motilin (MTL) in serum in different groups were detected via enzyme-linked immunosorbent assay. Expressions of epidermal growth factor (EGF) and trefoil factor 2 (TFF2) protein in gastric tissues were detected via immunohistochemistry, and expressions of c-Jun N-terminal kinase (JNK), P53, Bcl-2-associated X protein (Bax), and Caspase-3 protein in gastric tissues were detected via western blotting.

RESULTS

The EO from patchouli and tangerine peel at 1:2 ratio of compatibility significantly improved gastric mucosal injury, decreased serum GAS and PGC contents, and increased the PGE2 level in serum (p < 0.05). The mixture of EO from patchouli and tangerine peel (Mix-EO) can reduce the formation of gastric mucosal ulcers, reduce gastric mucosal injury, improve the expansion of the endoplasmic reticulum of the chief cells, repair mitochondrial damage, and inhibit the secretion of gastric acid by parietal cells. Mix-EO at 300 mg/kg can reduce the expression of serum GAS, PGC, SP, CCK, and cAMP/cGMP (p < 0.05 or 0.01); increase the expression of EGF and TFF2 protein in gastric tissues (p < 0.01); and inhibit the expression of JNK, p53, Bax, and Caspase-3 proteins (p < 0.01).

CONCLUSION

The combination of EO from patchouli and tangerine peel can repair the gastric mucosal damage in GU rats and prevent the occurrence of ulcers by inhibiting the secretion of gastric acid, enhancing the defensive ability of gastric mucosa, and suppressing the apoptosis of gastric epithelial cells. Moreover, the optimal compatible ratio of patchouli and tangerine peel is 1:2.

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.

Bisphenol A (BPA) Affects the Enteric Nervous System in the Porcine Stomach

Bisphenol A (BPA) is widely utilized in plastic production process all over the world. Previous studies have shown that BPA, with its similarity to estrogen, may negatively affect living organisms. It is acknowledged that BPA distorts the activity of multiple internal systems, including the nervous, reproductive, urinary, and endocrine systems. BPA also affects the gastrointestinal tract and enteric nervous system (ENS), which is placed throughout the wall from the esophagus to the rectum. Contrary to the intestine, the influence of BPA on the ENS in the stomach is still little known. This study, performed using the double immunofluorescence method, has revealed that BPA affects the number of nervous structures in the porcine gastric wall immunoreactive to vesicular acetylcholine transporter (VAChT, a marker of cholinergic neurons), substance P (SP), vasoactive intestinal polypeptide (VIP), galanin (GAL) and cocaine- and amphetamine-regulated transcript peptide (CART). The character and severity of noted alterations depended on the part of the ENS, the BPA dose, and the type of neuronal substance. Administration of BPA resulted in an increase in the number of nervous structures containing SP, GAL, and/or CART, and a decrease in the number of cholinergic neurons in all parts of the gastric wall. The number of VIP-positive nervous structures increased in the enteric myenteric ganglia, along with the muscular and mucosal layers, whilst it decreased in the submucous ganglia. The exact mechanism of noted changes was not absolutely obvious, but they were probably related to the neuroprotective and adaptive processes constituting the response to the impact of BPA.

Can aprepitant used for nausea and vomiting be good gastrointestinal complaints?

Aprepitant is a selective SP/NK-1 receptor antagonist and used in postoperative and chemotherapeutics induced emesis and vomiting. The aim of our study is to show aprepitant may have beneficial effects on gastrointestinal complaints in cancer patients undergoing chemotherapeutics by indomethacin-induced gastric ulcer model. A total of 48 rats were fasted 24 h for ulcer experiment. Aprepitant doses of 5, 10, 20, and 40 mg/kg were evaluated for their antiulcer activity. Omeprazole (20 mg/kg) was used as a positive control group. Six hours after 25 mg/kg indomethacin administration, all stomachs were dissected out. After macroscopic analyses, tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), COX-1, and COX-2 mRNA levels and SOD activity, and GSH and MDA levels of stomachs were determined. Histopathological examinations were evaluated. Aprepitant administration exerted 48.14%, 49.62%, 65.92%, and 76.77% ulcer inhibition effects at 5, 10, 20, and 40 mg/kg, respectively. Aprepitant administration decreased oxidative stress and inflammatory parameters in stomach tissues dose dependently. Aprepitant administration increased stomach COX-2 mRNA levels at 20 and 40 mg/kg doses. Although aprepitant appears to be disadvantageous in terms of treating gastric ulcer due to COX enzyme inhibition according to the previous studies, aprepitant has been shown to have ulcer healing effect in our study. When aprepitant is given as an anti-nausea and vomiting drug to cancer patients undergoing chemotherapy, we can argue that it will not be necessary to add a new gastric protective agent as it also shows beneficial effects in gastrointestinal complaints.

Ju Re Ba Du therapy for Postherpetic neuralgia: A protocol for systematic review and meta-analysis

INTRODUCTION

Postherpetic neuralgia (PHN) is one of the most common types of chronic neuropathic pain, which seriously affects quality of the life because of pain severity and poor response to the currently available treatments. Ju Re Ba Du therapy as a form of acupuncture therapy which is proved to be effective in RCTs and very suitable for patients, has been used in Postherpetic neuralgia in patients for a long time, therefore a systematic review is necessary to provide available evidence for further study.

METHODS AND ANALYSIS

The following databases will be searched from their inception to October 2020: Electronic database includes PubMed, Embase, Cochrane Library, Web of Science, Nature, Science online, VIP medicine information, and CNKI (China National Knowledge Infrastructure).

PRIMARY OUTCOME

pain intensity assessed on a visual analogue scale (VAS); Additional outcomes:Data will be extracted by two researchers independently, risk of bias of the meta-analysis will be evaluated based on the Cochrane Handbook for Systematic Reviews of Interventions. All data analysis will be conducted by data statistics software Review Manager V.5.3. and Stata V.12.0.

RESULTS

The results of this study will systematically evaluate the effectiveness and safety of Ju Re Ba Du therapy intervention for people with Postherpetic neuralgia.

CONCLUSION

The systematic review of this study will summarize the current published evidence of Ju Re Ba Du therapy for the treatment of Postherpetic neuralgia, which can further guide the promotion and application of it.

ETHICS AND DISSEMINATION

This study is a systematic review, the outcomes are based on the published evidence, so examination and agreement by the ethics committee are not required in this study. We intend to publish the study results in a journal or conference presentations.

OSF REGISTRATION NUMBER

September 29, 2020 osf.io/r6y9b. (https://osf.io/r6y9b).

Reciprocal association between depression and peptic ulcers: Two longitudinal follow-up studies using a national sample cohort

This study was aimed to explore the bidirectional association between depression and peptic ulcers. The ≥20-year-old participants of the Korean National Health Insurance Service-National Sample Cohort from 2002 to 2013 were included in the study. In study I, 30,306 depression patients were 1:4 matched with 121,224 control I participants. In study II, 127,590 peptic ulcer patients were 1:1 matched with 127,590 control II participants. The stratified Cox-proportional hazards models were used to analyse the hazard ratio (HR) of depression for peptic ulcers (study I) and of peptic ulcers for depression (study II). A total of 8.9% (2,703/ 30,306) of depression patients and 7.3% (8,896/ 121,224) of patients in the control I group had peptic ulcers (P < 0.001). The depression group had an adjusted HR for peptic ulcers that was 1.14-fold higher than that of the control I group (95% confidence interval [95% CI] = 1.09–1.19, P < 0.001). A total of 6.4% (8,144/ 127,590) of peptic ulcer patients and 3.5% (4,515/127,590) of patients in the control II group had depression (P < 0.001). The peptic ulcer group had an adjusted HR for depression that was 1.68-fold higher than that of the control II group (95% CI = 1.62–1.74, P < 0.001). Depression and peptic ulcers exhibited a bidirectional relationship.