Water-immersion Restraint Research Articles

H2S Donors Reverse Age-Related Gastric Malfunction Impaired Due to Fructose-Induced Injury via CBS, CSE, and TST Expression.

ObjectiveExcess of fructose consumption is related to life-treating conditions that affected more than a third of the global population. Therefore, to identify a newer therapeutic strategy for the impact prevention of high fructose injury in age-related malfunctions of the gastric mucosa (GM) in the animal model is important.MethodsAdult and aged male rats were divided into control groups (standard diet, SD) and high fructose diet (HFD) groups; acute water immersion restraint stress (WIRS) was induced for evaluation of GM adaptive response and effects of testing the therapeutic potential of H2S-releasing compounds (H2S donors). Histological examination of gastric damage was done on hematoxylin-eosin stained slides. Cystathionine beta-synthase (CBS), Cystathionine gamma-lyase (CSE), and Thiosulfate-dithiol sulfurtransferase (TST) activities and oxidative index were assessed during exogenous administration of H2S donors: sodium hydrosulfide (NaHS) and the novel hybrid H2S-releasing aspirin (ATB-340). The results showed that HFD increased gastric damage in adult and aged rats. HFD-associated malfunction characterized by low activities of H2S key enzymes, inducing increased oxidation. Pretreatment with NaHS, ATB-340 of aged rats in the models of HFD, and WIRS attenuated gastric damage in contrast to vehicle-treated group (p < 0.05). The effect of ATB-340 was characterized by reverse oxidative index and increased CBS, CSE, and TST activities. In conclusion, H2S donors prevent GM age-related malfunctions by enhancement of CBS, CSE, and TST expression against fructose excess injury though reduction of oxidative damage.

New insights into the effects of caffeine on adult hippocampal neurogenesis in stressed mice: Inhibition of CORT-induced microglia activation.

Chronic stress-evoked depression has been implied to associate with the decline of adult hippocampal neurogenesis. Caffeine has been known to combat stress-evoked depression. Herein, we aim to investigate whether the protective effect of caffeine on depression is related with improving adult hippocampus neurogenesis and explore the mechanisms. Mouse chronic water immersion restraint stress (CWIRS) model, corticosterone (CORT)-established cell stress model, a coculture system containing CORT-treated BV-2 cells and hippocampal neural stem cells (NSCs) were utilized. Results showed that CWIRS caused obvious depressive-like disorders, abnormal 5-HT signaling, and elevated-plasma CORT levels. Notably, microglia activation-evoked brain inflammation and inhibited neurogenesis were also observed in the hippocampus of stressed mice. In comparison, intragastric administration of caffeine (10 and 20mg/kg, 28days) significantly reverted CWIRS-induced depressive behaviors, neurogenesis recession and microglia activation in the hippocampus. Further evidences from both in vivo and in vitro mechanistic experiments demonstrated that caffeine treatment significantly suppressed microglia activation via the A2AR/MEK/ERK/NF-κB signaling pathway. The results suggested that CORT-induced microglia activation contributes to stress-mediated neurogenesis recession. The antidepression effect of caffeine was associated with unlocking microglia activation-induced neurogenesis inhibition.

Nervous mechanisms of restraint water-immersion stress-induced gastric mucosal lesion.

Stress-induced gastric mucosal lesion (SGML) is one of the most common visceral complications after trauma. Exploring the nervous mechanisms of SGML has become a research hotspot. Restraint water-immersion stress (RWIS) can induce GML and has been widely used to elucidate the nervous mechanisms of SGML. It is believed that RWIS-induced GML is mainly caused by the enhanced activity of vagal parasympathetic nerves. Many central nuclei, such as the dorsal motor nucleus of the vagus, nucleus of the solitary tract, supraoptic nucleus and paraventricular nucleus of the hypothalamus, mediodorsal nucleus of the thalamus, central nucleus of the amygdala and medial prefrontal cortex, are involved in the formation of SGML in varying degrees. Neurotransmitters/neuromodulators, such as nitric oxide, hydrogen sulfide, vasoactive intestinal peptide, calcitonin gene-related peptide, substance P, enkephalin, 5-hydroxytryptamine, acetylcholine, catecholamine, glutamate, γ-aminobutyric acid, oxytocin and arginine vasopressin, can participate in the regulation of stress. However, inconsistent and even contradictory results have been obtained regarding the actual roles of each nucleus in the nervous mechanism of RWIS-induced GML, such as the involvement of different nuclei with the time of RWIS, the different levels of involvement of the sub-regions of the same nucleus, and the diverse signalling molecules, remain to be further elucidated.

Effect of acupuncture on serum inflammatory cytokines and intestinal flora in rats with stress-induced gastric ulcer

To investigate the effect of acupuncture on serum inflammatory cytokines and intestinal flora in rats with stress-induced gastric ulcer (SGU), and to explore the mechanism of acupuncture in the treatment of SGU. Sprague-Dawley rats were randomly divided into blank, model, acupuncture, and medication groups, with 7 rats in each group. Restraint water-immersion stress was used to establish the model of SGU. The rats in the acupuncture group were given acupuncture at "Zhongwan"(CV12) and bilateral "Zusanli"(ST36) for 20 min, once a day for 5 days, and those in the medication group were given 2 mL solution of Omeprazole enteric-coated tablets (0.2 mg/kg) by gavage, once a day for 5 days. The Guth method was used to calculate the gastric mucosa damage index, HE staining was used to observe the histopathological changes of the gastric mucosa, ELISA was used to measure the serum levels of interleukin-4 (IL-4) and interleukin-6 (IL-6), and 16S rDNA sequencing method was used to observe the change in intestinal flora. Compared with the blank group, the model group had a significant increase in gastric mucosa damage index (P<0.01), markedly pathological changes of the gastric mucosa shown by HE staining, a significant reduction in the content of serum IL-4 (P<0.01), and a significant increase in the content of serum IL-6 (P<0.01), as well as a significant reduction in Bacteroidetes and Firmicutes at the phylum level. Compared with the model group, the acupuncture group and the medication group had a significant reduction in gastric mucosa damage index (P<0.01, P<0.05). HE staining showed reduced pathological changes of the gastric mucosa, as well as a significant increase in the content of serum IL-4 (P<0.01, P<0.05) and a significant reduction in the content of serum IL-6 (P<0.01, P<0.05). As for the intestinal flora, there was a significant increase in Bacteroidetes. Compared with the medication group, the gastric mucosa damage index was decreased （P<0.05），the content of serum IL-4 was significantly increased （P<0.05）, while the content of serum IL-6 significantly decreased (P<0.05) in the acupuncture group. Acupuncture at CV12 and ST36 can down-regulate the content of serum IL-6, up-regulate the content of serum IL-4, maintain the relative homeostasis of inflammatory cytokines, and regulate the community structure of intestinal flora, and thus help to repair the damage of gastric mucosa.

Effect of acupuncture on intestinal flora in rats with stress gastric ulcer

To observe the effect of acupuncture at "Baihui" (GV 20), "Zhongwan" (CV 12) and "Zusanli" (ST 36) on intestinal flora in rats with stress gastric ulcer (SGU) , and to explore the mechanism of acupuncture promoting SGU recovery. Thirty-one SPF SD rats were randomly divided into a control group (7 rats), a model control group (8 rats), an acupuncture group (8 rats) and a medication group (8 rats). The rats in the model group, acupuncture group and medication group were selected to applied the improved restraint water-immersion stress method to establish the SGU model. After modeling, the rats in the control group and model group were fixed and restrained for 20 min every day for a total of 5 days; the rats in the acupuncture group were intervented with acupuncture at "Baihui" (GV 20), "Zhongwan" (CV 12) and "Zusanli" (ST 36), once a day, 20 min each time, and twisting needle for 30 s every 5 min for a total of 5 days; the rats in the medication group were gavaged by solution of omeprazole enteric-coated tablet (200 mg/mL), 2 mL for each rat, once a day. Guth method was used to calculate the gastric mucosal damage index (GMDI), HE staining was used to observe the pathological changes of gastric mucosa, and 16SrDNA identification was used to detect the structural abundance of intestinal flora. Compared with the control group, the GMDI of rats in the model group was increased (P<0.01), the gastric mucosal pathological changes were significant, and the intestinal flora richness index Chao1, Observed species and diversity index Shannon were all decreased (P<0.05), the diversity index Simpson was increased (P<0.05). Compared with the model group, the GMDI of rats in the acupuncture group and medication group was reduced (P<0.01, P<0.05), the gastric mucosal damage degree was reduced, and the intestinal flora richness index Chao1, Observed species and diversity index Shannon were all increased (P<0.05) and the diversity index Simpson decreased (P<0.05). Compared with the medication group, the GMDI of rats in the acupuncture group was reduced (P<0.01), the recovery of gastric mucosal injury was better than that of the medication group. Acupuncture can effectively improve gastric mucosal injury of SGU, and the mechanism may be related to increasing the diversity of intestinal flora and promoting the correction of the disordered intestinal flora.

Comparative Effects of Taurine, Vitamin E and Nuclea latifolia (Stem‐Bark) Extract on Object Regonition and Anxiety on Wistar Rats Subjected to Water Immersion Restraint Stress

Stress is the feeling of emotional or physical tension, that may arise from any event or thought that makes person become frustrated, angry, or nervous. Anxiety and cognitive impairment can be normal during stressful situations. The comparative effect of Taurine, Vitamin E, and Nuclea Latifolia (Stem back) extract object recognition and anxiety in wistar rats subjected to water immersion restraint stress was carried out. Total of twenty four rats weighing between 100g – 120 g were used for this study. The animals were divided into four groups before the commencement of the experiment as follows: Group A: Serves as the control and received 1ml/kg distilled water for three weeks. Group B: Received 0.2 ml/kg vitamin E for three weeks. Group C: Received 200 mg/kg taurine (TAU) for three weeks and Group D: Received 200 mg/kg of Nauclea latifolia (NL) (stem bark) extract for three weeks. At the end of the three weeks, animals were starved for 24 hours before the commencement of the stress procedure. They were anesthetized using chloroform vapour after which they were restraint on a wooden plank (25 by 19 cm) with the four arms anchored horizontally and were immersed into water up to the xiphoid level for two hours. After the stress procedure, object recognition task and anxiety behaviours were assessed. The result of the training phase on object recognition showed that, TAU group explored the novel object more (64.92 %) followed by Vit. E group (63.90 %). The NL group has the least percentage (52.75 %) in exploring the novel object that was presented to the animals. During the test phase, it was noticed that, the TAU together with Vit. E groups showed similar behaviour with that of the training phase as they explored the Novel object presented to them more (71.52 %) and (70.05 %) respectively. On the anxiety model, while the Vit. E group shows significant increase in the number of entries into the open arm, the Tau group revealed significant decrease in the number of entries into the closed arm. Vit. E, Tau and NL groups showed significant increase in time spent by the animals in the open arm. The researched therefore, showed that Taurine and Vitamin E improved object recognition in the rats and also inhibited anxiety‐like behavior in Wistar rats that were subjected to water immersion restraint stress.Support or Funding InformationPersonal Funding

Inhibition of GKN2 Attenuates Acute Gastric Lesions Through the NLRP3 Inflammasome.

Objective: Acute gastric lesions are commonly seen in critically ill patients in the intensive care unit and can result in significant upper gastrointestinal bleeding. However, the signaling mechanisms that regulate this severe disease are still unclear. In this study, we explored the involvement of gastrokine 2 (GKN2) in the development of acute gastric lesions in mice. Approach: We measured the degree of injury using the water immersion restraint stress mouse model. Inflammatory cells and factors were analyzed after gastric lesion induction. The luciferase reporter assay was used to detect the transcription activity of nuclear receptor subfamily 3 group C member 1 (NR3C1) in regulation of GKN2. We also detected the downstream pathway of GKN2 in gastric lesions. Results: The results showed that GKN2 could aggravate stress-induced gastric lesions and gastric mucosal cell death. Moreover, the gastric lesion promoted by GKN2 was gastric acid independent. GKN2 could recruit neutrophils and promote the release of inflammatory factors to contribute to inflammation. NR3C1, activated by cortisol under stress, could act as a transcription factor to upregulate the expression of GKN2. Innovation: This study elucidates the process of gastric lesion at a molecular level and explores the possible contender biomarkers for diagnosis and drug targets in wound healing of gastric lesions. Conclusion: In conclusion, GKN2, which was upregulated by cortisol, aggravated the gastric lesion through activation of the inflammasome and inflammatory reaction.

DUOX2, a common modulator in preventive effects of monoamine-based antidepressants on water immersion restraint stress- and indomethacin- induced gastric mucosal damage

Multiple kinds of monoamine-based antidepressants have been shown prophylactic effects in experimentally induced gastric ulcer. The loss of redox homeostasis plays a principle role in the development of peptic mucosal damage. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases are one of the most important sources of reactive oxygen species within the gastrointestinal tract. It is unclear whether there are some common NADPH oxidases modulated by monoamine-based antidepressants in different gastric mucosal damage models. We explored the effects of selective serotonin-norepinephrine reuptake inhibitor (SNRI) duloxetine on the reactive oxygen species production and antioxidant capacity in the gastric mucosa of water immersion restraint (WIRS) or indomethacin treated rats, and examined the role of NADPH oxidases in the protective effects. Pretreated duloxetine prevented the increase of gastric mucosal NADPH oxidase activity and NADPH oxidase inhibitor apocynin dose-dependently protected gastric mucosa from damage by the two factors. Furthermore, dual oxidase 2 (DUOX2) and NADPH oxidase4 (NOX4) are involved in the protective effects of duloxetine in both models. We then examined NADPH oxidases expression modulated by the other monoamine-based antidepressants including selective serotonin reuptake inhibitor (SSRIs) fluoxetine, tricyclic agent (TCAs) amitriptyline and monoamine oxidase inhibitor (MAOs) moclobemide in the two models, and all the three antidepressants reduced the DUOX2 expression in the gastric mucosa. So DUOX2 was a common modulator in the preventive effects of all the monoamine-based antidepressants on WIRS- and indomethacin-induced gastric lesion. Our work provided a peripheral joint molecular target for monoamine modulatory antidepressants, which may be helpful to reveal the mechanisms of this kind of drugs more than monoamine regulation.

The gastroprotective effect of the foxtail millet and adlay processing product against stress-induced gastric mucosal lesions in rats

Foxtail millet (Setaria italica (L.) P. Beauv.) and adlay (Coix lachryma-jobi L. var. ma-yuen Stapf.) seeds have substantial benefits possesses remarkable edible and nutritive values, and ease of processing and food manufacturing. They have nutraceutical properties in the form of antioxidants which prevent deterioration of human health and have long been used in traditional Chinese medicine as a remedy for many diseases. The present study is designed to investigate the gastroprotective effect of foxtail millet and adlay processing product (APP) diet on water immersion restraint stress (WIRS) induced ulceration in rats. We examined the effects of intake of AIN-93G diet containing either foxtail millet (10, 20 and 40%, 4 weeks) or APP (15 and 30%, 5 weeks) on macroscopic ulcer index (UI), plasma calcium level, lipid peroxidation products (estimated by the thiobarbituric acid reactive substances; TBARS), non-protein sulfhydryl (NPSH), digestive enzyme activities, and histopathology were determined. The results showed that pretreatment with millet and adlay diets significantly prevented the gastric mucosal lesion development. In addition, ulcerated rats showed depletion of NPSH levels whereas treatment with millet and adlay reverted this decline in stress-induced rats. Histological studies confirmed the results. The finding suggests that millet and adlay diets promote ulcer protection by the decrease in ulcer index, TBARS values and increase NPSH concentrations. Millet and adlay diets retain the advantage of being a natural product which may protect the gastric mucosa against ulceration.

Microglia polarization of hippocampus is involved in the mechanism of Apelin-13 ameliorating chronic water immersion restraint stress-induced depression-like behavior in rats

Chronic stress induces the activation of hippocampal microglia, which produces many inflammatory mediators and mediates the occurrence of depression. Two phenotypes of microglia polarization, the classical M1 and alternative M2, play important regulatory roles in neuroinflammation and are involved in the occurrence and development of depression. Apelin is derived from a precursor peptide consisting of 77 amino acids and is a natural ligand for the orphan G-protein-coupled receptor APJ. Apelin-13 is one of the subtypes of Apelin and has a wide range of biological effects. Studies have shown that Apelin-13 has an antidepressant effect, but its specific mechanism has not been elucidated. In this study, the purpose of this study is to explore the possible mechanism of Apelin-13 to improve depression-like behaviors induced by chronic stress in rats from the perspective of microglial polarization in vivo. Adult male Sprague Dawley (SD) rats received 28 days of chronic water immersion restraint stress (CWIRS). Apelin group was injected with Apelin-13 (2 μg/2 μL) through the intracerebroventricular for 7 days. The results showed that CWIRS can induce depression-like behaviors in rats. Compared with the CWIRS + saline group, the CWIRS + Apelin-13 group was significantly improved the depression-like behaviors in rats. Compared with the CWIRS + saline group, the CWIRS + Apelin-13 group was significantly down-regulated the protein expression of M1-type marker iNOS and the pro-inflammatory factors IL-1β and IL-6 secret by microglia decreased. Compared with the CWIRS + saline group, the protein expression of M2-type marker Arg1 and anti-inflammatory factors IL-4 and IL-10 secreted by microglia was significantly increased in CWIRS + Apelin-13 group. Double-labelling immunofluorescence co-localization showed that, compared with the CWIRS + saline group, CWIRS + Apelin-13 group significantly inhibited the co-localization expression of Iba-1 and iNOS, and promoted the co-localization expression of Iba-1 and Arg1 in hippocampus microglia. Taken together, our study suggests that Apelin-13 improves depression-like behavior in rats induced by CWIRS and its mechanism may be related to the regulation of microglial polarization.

Dolichos lablab L. extracts as pharmanutrient for stress-related mucosal disease in rat stomach.

Gastric stress-related mucosal disease (SRMD) presented from superficial gastritis to deep ulceration consequent to insufficient perfusion, ischemia, and oxidative stress. Though pharmacologic interventions to optimize tissue perfusion or to enhance defensive mechanism are essential, limited clinical outcome necessitates strong acid suppressors or natural agents. Under the hypothesis that Dolichos lablab L. (NKM 23-1) can enhance defense against SRMD, water immersion restraint stress (WIRS) were imposed to rats and additional groups pretreated with differing doses of NKM 23-1 were monitored. On gross and microscopic evaluation, they significantly rescued SRMD (p<0.01). The levels of inflammatory mediators such as IL-18, IL-1β, IL-8, iNOS, TNF-α, caspase-1, NOXs as well as MMPs accompanied with NF-κB p50 activation were all significantly increased in WIRS, but their levels were significantly decreased in Groups pretreated with NKM 23-1. WIRS significantly increased apoptosis, but significantly decreased with NKM 23-1 accompanied with significantly increased levels of cyclin D/E and HSP70/HSP27. Gastric mucin was significantly preserved in Groups pretreated with NKM 23-1, while depleted in WIRS, accompanied with increased expressions of Muc5A. Gastric levels of HO-1 and NQO1 were significantly increased in Group treated with NKM 23-1 with transcriptional activation of Nrf2. Conclusively, preemptive intake of NKM 23-1 significantly rescued SRMD.

Effects of Crystalline and Amorphous Forms of Paramylon from &lt;i&gt;Euglena gracilis&lt;/i&gt; on the Development of Water-immersion Restraint Stress-induced Gastric Ulcer

Effects of Crystalline and Amorphous Forms of Paramylon from &lt;i&gt;Euglena gracilis&lt;/i&gt; on the Development of Water-immersion Restraint Stress-induced Gastric Ulcer

Proteomics of the mediodorsal thalamic nucleus of rats with stress-induced gastric ulcer.

BACKGROUNDStress-induced gastric ulcer (SGU) is one of the most common visceral complications after trauma. Restraint water-immersion stress (RWIS) can cause serious gastrointestinal dysfunction and has been widely used to study the pathogenesis of SGU to identify medications that can cure the disease. The mediodorsal thalamic nucleus (MD) is the centre integrating visceral and physical activity and contributes to SGU induced by RWIS. Hence, the role of the MD during RWIS needs to be studied.AIMTo screen for differentially expressed proteins in the MD of the RWIS rats to further elucidate molecular mechanisms of SGU.METHODSMale Wistar rats were selected randomly and divided into two groups, namely, a control group and an RWIS group. Gastric mucosal lesions of the sacrificed rats were measured using the erosion index and the proteomic profiles of the MD were generated through isobaric tags for relative and absolute quantitation (iTRAQ) coupled with two-dimensional liquid chromatography and tandem mass spectrometry. Additionally, iTRAQ results were verified by Western blot analysis.RESULTSA total of 2853 proteins were identified, and these included 65 dysregulated (31 upregulated and 34 downregulated) proteins (fold change ratio ≥ 1.2). Gene Ontology (GO) analysis showed that most of the upregulated proteins are primarily related to cell division, whereas most of the downregulated proteins are related to neuron morphogenesis and neurotransmitter regulation. Ingenuity Pathway Analysis revealed that the dysregulated proteins are mainly involved in the neurological disease signalling pathways. Furthermore, our results indicated that glycogen synthase kinase-3 beta might be related to the central mechanism through which RWIS gives rise to SGU.CONCLUSIONQuantitative proteomic analysis elucidated the molecular targets associated with the production of SGU and provides insights into the role of the MD. The underlying molecular mechanisms need to be further dissected.

Moxibustion improved gastric ulcer by reducing contents of corticotrophin-releasing hormone and adrenocorticotropic hormone in serum and hypothalamus-pituitary tissues in rats with stress-induced gastric ulcer

To observe the effect of moxibustion of "Zhongwan" (CV12) and "Zusanli" (ST36) on histopathological changes of the gastric mucosa and contents of corticotropin-releasing hormone(CRH) and adrenocorticotrophic hormone(ACTH) in the serum, hypothalamus and pituitary tissues in rats with stress-induced gastric ulcer(SGU), so as to reveal its mechanisms underlying improvement of SGU. A total of 28 male SD rats were randomly divided into blank control, model, moxibustion, and medication groups, with 7 rats in each group. The SGU model was established by water immersion restraint stress for 3 h. Moxibustion was applied to "Zhongwan"(CV12) and bilateral "Zusanli" (ST36) for 20 min, once a day for 5 days, and rats of the medication group were treated by gavage of Omeprazole enteric-coated tablets (0.2 mg/kg) once a day for 5 days. The gastric mucosal damage index (ulcer index, UI) was measured to assess the injury severity according to Guth's me-thods. Histopathological changes of the gastric mucosa were determined by H．E. staining. The contents of CRH in serum and hypothalamus and ACTH in serum and pituitary gland tissue were assayed by using ELISA. Outcomes of H．E. staining showed gastric mucosal epithelia defect, disordered arrangement of glands, obvious mucosal hyperemia and edema, exudation of a large number of red blood cells, swelling of mucosal cells with necrosis of nuclei in the model group. These situations were relatively milder in the moxibustion and medication groups. After modeling, the UI, and the contents of CRH in the serum and hypotha-lamus, and ACTH in the serum and pituitary tissue were significantly increased in comparison with the blank control group (P<0.01). Following the intervention, the UI, and contents of CRH in the serum and hypothalamus, and ACTH in the serum and pituitary were all down-regulated in both medication and moxibustion groups relevant to the model group (P<0.05, P<0.01). The therapeutic effect of moxibustion was notably superior to that of medication in down-regulating serum CRH and ACTH (P<0.05). No significant differences were found between the medication and moxibustin interventions in lowering the UI, hypothalamic CRH and pituitary ACTH levels (P>0.05)．. Moxibustion can relieve gastric mucosal injury induced by stress in water immersion restraint stress rats, which may be associated with its effects in down-regulating the levels of CRH and ACTH in se-rum, hypothalamus and pituitary tissues (inhibition of activities of hypothalamic-pituitary-adrenocortical axis)．.

Effects of Restraint Water-Immersion Stress-Induced Gastric Mucosal Damage on Astrocytes and Neurons in the Nucleus Raphe Magnus of Rats via the ERK1/2 Signaling Pathway

Restraint water-immersion stress (RWIS) consists of psychological and physical stimulation, and it has been utilized in the research of gastric mucosal damage. It has been shown by previous studies that the nucleus raphe magnus (NRM) is closely involved in the gastrointestinal function, but its functions on the stress-induced gastric mucosal injury (SGMI) have not been thoroughly elucidated to date. Consequently, in this research, we aim to measure the expression of astrocytic glial fibrillary acidic protein (GFAP), neuronal c-Fos, and phosphorylation extracellular signal regulated kinase 1/2 (p-ERK1/2) in the process of RWIS with immunohistochemistry and western blot methods. What is more, we detect the relation between astrocytes and neurons throughout the stress procedure and explore the regulation of the ERK1/2 signaling pathway on the activity of astrocytes and neurons after RWIS. The results indicated that all three proteins expression multiplied following peaked 3h substantially. The SMGI, astrocyte and neuron activity were affected after the astrocytotoxin L-A-aminohexanedioic acid (L-AA) and c-fos antisense oligonucleotide (ASO) injections. After the injection of PD98059, the gastric mucosal injury, astrocyte and neuron activity significantly fell off. These results suggested that RWIS-induced activity of astrocytes and neurons in the NRM may play a significant part in gastric mucosa damage via the ERK1/2 signaling pathway.

Polysaccharide-Rich Extract of Phragmites rhizome Attenuates Water Immersion Stress and Forced Swimming Fatigue in Rodent Animal Model.

Our study aimed to investigate the effects of the polysaccharide-rich extract of Phragmites rhizoma (PEP) against water immersion restraint (WIR) stress and forced swimming-induced fatigue. Exposure to WIR stress significantly increased the ulcer index, bleeding score, the weight of the adrenal gland, blood glucose concentrations, total cholesterol, cortisol, and creatine kinase (CK). The weight of the spleen decreased significantly. In addition, myeloperoxidase (MPO) and thiobarbituric acid-reactive substance (TBARS) were significantly upregulated by WIR stress. The antioxidative factors such as glutathione (GSH) and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the stomach were decreased by WIR stress. Alterations induced by WIR stress were effectively reversed by pretreatment with PEP. The swimming endurance capacity of mice was significantly prolonged by the oral administration of PEP. Swimming-induced fatigue significantly reduced the body weight; however, the injection of PEP inhibited the decrease of body weight. The PEP-treated group had significantly lower CK levels in plasma, an indicator of muscle damage. These results indicated that PEP has anti-stress and anti-fatigue effects, which are mediated by suppressing the hyperactivation of the hypothalamus-pituitary-adrenal axis, and antagonism of the oxidative damages induced by WIR stress and prolonged swimming times.

Effects of Tegoprazan, a Novel Potassium-Competitive Acid Blocker, on Rat Models of Gastric Acid-Related Disease.

Tegoprazan, a novel potassium-competitive acid blocker (P-CAB), is a next-generation therapeutics developed for the treatment of acid-related gastrointestinal diseases such as gastroesophageal reflux disease (GERD) and peptic ulcers. In the present study, the in vitro and in vivo pharmacological properties of tegoprazan were compared with those of esomeprazole, a representative proton pump inhibitor. In vitro enzyme assays were performed using ion-leaky vesicles containing gastric H+/K+-ATPases isolated from pigs. The in vivo efficacies of tegoprazan were evaluated in rat models of GERD and peptic ulcer. Tegoprazan inhibited the activity of porcine H+/K+-ATPase with an IC50 value of 0.53 μM in a reversible manner, whereas esomeprazole showed weak and irreversible inhibition with an IC50 value of 42.52 μM. In a GERD model, tegoprazan showed dose-dependent efficacy in inhibiting esophageal injury and gastric acid secretion with an ED50 of 2.0 mg/kg, which was 15-fold more potent than that of esomeprazole. In peptic ulcer models, tegoprazan exhibited superior antiulcer activity compared with esomeprazole. The ED50 of tegoprazan in the naproxen-, ethanol-, and water-immersion restraint stress-induced peptic ulcer models were 0.1, 1.4, and 0.1 mg/kg, respectively. In the acetic acid-induced peptic ulcer model, the curative ratio of tegoprazan at 10 mg/kg was higher than that of esomeprazole at 30 mg/kg (44.2% vs. 32.7%, respectively), after 5 days of repeated oral administration. Thus, tegoprazan is a novel P-CAB that shows potent and reversible inhibition of gastric H+/K+-ATPase and may provide stronger efficacy compared with previous proton pump inhibitors.

The reduced bactericidal activity of neutrophils as an incisive indicator of water-immersion restraint stress and impaired exercise performance in mice

The incisive evaluation of psychological stress may be required to determine the exercise performance of stressed hosts. We investigated objective markers of psychological stress that reflect exercise performance, focusing on the neutrophil function. We used murine water-immersion restraint (WIR) stress for our assessments. After receiving WIR for 1 or 2 h, mice were exercised on an airtight treadmill that monitors their respiratory exchange ratio. The neutrophil function was analyzed after WIR stress. Although the control mice (without WIR) showed good combustion of both carbohydrates and lipids as energy sources during treadmill exercise, mice that underwent 2-h WIR did not combust carbohydrates or lipids effectively, drastically reducing their performance. In contrast, the 1-h WIR mice showed carbohydrate combustion (albeit a slow response) but did not use lipids for energy, thereby running longer than the 2-h WIR mice but shorter than the control mice. The bactericidal activity of neutrophils, but not their superoxide production or microsphere-phagocytic activity, was significantly reduced by 1-h WIR and further reduced by 2-h WIR, indicating a significant association between WIR stress and exercise performance. The neutrophil bactericidal activity may be a good indicator of psychological stress and a useful tool for precisely assessing exercise performance.

Olea europaea subsp. Cuspidata and Juniperus procera Hydroalcoholic Leaves' Extracts Modulate Stress Hormones in Stress-Induced Cystitis in Rats

Objective: To study the effect of Saudi medicinal plant in stress-induced cystitis in experimental rats. Materials and Methods: Seventy-two female Sprague Dawley rats (200–250 g) were divided into eight groups of 9 rats each. Group 1 and 2 are controls assigned nonstressed and stressed, respectively. Other six groups received different treatments for 2 weeks. After the 14 days of treatment, each group was exposed to water-immersion restraint stress (WIRS) for 30 min. Blood samples were collected to measure the corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH) levels. The rats were sacrificed, and their urinary bladders were isolated immediately for a histological and immunohistochemical examination. Results: Rats exposed to WIRS had lesions in the urinary bladder, with a significant increase in plasma CRH and ACTH levels in comparison to the nonstressed controls. Bladder cut sections in stressed rats showed no gross structural abnormality in smooth muscle and connective tissue ratio. There were noticeable variations in mast cell (MC) infiltration and activity with a loss of more than 20% of cellular staining and a significant increase in the number of red blood cell-filled blood vessels. Our findings showed that supplementation of Olea europaea leaf extract (OEE) or Juniperus procera leaf extract (JPE) reduced the MC infiltration and significantly reduced stress hormones compared to the stressed controls. Conclusions: The present study demonstrated that OEE/JPE alone and their combination have a potential protective effect against stress-induced cystitis in rats. The underlying mechanism of the present study also resulted in a decrease in CRH and ACTH stress hormones.

Apelin-13 ameliorates chronic water-immersion restraint stress-induced memory performance deficit through upregulation of BDNF in rats

A large number of studies have demonstrated that the hippocampus has important influences on stress response and memory. The abundant expressions of apelin and its receptor APJ in the hippocampus may imply potential involvement of apelin/APJ signaling in modulating stress-related memory performance deficit. In our previous study, apelin-13 ameliorates memory performance deficit in acute stressed rats. Here, we further examined whether apelin-13 can ameliorate memory performance deficit in chronic stressed rats. Rats were exposed to chronic water-immersion restraint stress (CWIRS) for 4 weeks. After stress withdrawal, apelin-13 was intracerebroventricularly infused once a day for one week. The novel object recognition test (NORT) and Y-maze test (YMT), two hippocampus-dependent memory tasks, were performed to assess memory performance. We found that apelin-13 restored CWIRS-induced decline in the discrimination index and alternation ratio in NORT and YMT, respectively. Furthermore, apelin-13 ameliorated CWIRS-induced hippocampal BDNF expression deficit, and the TrkB receptor antagonist ANA-12 blocked the ameliorative effect of apelin-13 on memory performance deficit in CWIRS rats. The current observations indicate that apelin-13 ameliorates CWIRS-induced memory performance deficit through upregulation of BDNF in rats.