Anxiety and helplessness in the face of stress predisposes, precipitates, and sustains gastric ulceration

The Impact of Psychotrauma and Emotional Stress Vulnerability on Physical and Mental Functioning of Patients with Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic health condition thought to be influenced by personal life experiences and emotional stress sensitivity (neuroticism). In the present study, we examined the impact of cumulative trauma experiences and trait neuroticism (as a measure for emotional stress vulnerability) on physical and mental functioning of n = 211 patients diagnosed with IBD (112 Crohn's disease, 99 ulcerative colitis). All patients were assessed for self-reported trauma histories, emotional stress vulnerability, clinical disease activity, functional gastrointestinal (GI) symptoms, and quality of life. Results showed that patients with severe IBD activity have endured significantly more interpersonal trauma and victimization than those with quiescent IBD. Moreover, cumulative trauma was found to exert an indirect (neuroticism-mediated) effect on patients' symptom complexity, with trauma and neuroticism conjointly explaining 16-21% of the variance in gastrointestinal and 35% of the variance in mental symptoms. Upon correction for condition (using a small group of available controls, n = 51), the predictive capacity of trauma and neuroticism increased further, with both predictors now explaining 31% of the somatic-and almost 50% of the mental symptom heterogeneity. In terms of trauma type, victimization (domestic violence and intimate abuse) proved the best predictor of cross-sample symptom variability and the only trauma profile with a consistent direct and indirect (neuroticism-mediated) effect on patients' mental (QoL) and physical fitness. Results are consistent with the growing body of evidence linking experiential vulnerability factors (trauma and neuroticism) and associated feelings of personal ineffectiveness, helplessness, and uncontrollability to interindividual differences in (GI) disease activity and quality of life.

Geraniol accelerates the gastric healing, minimizes ulcers recurrence, and reduces anxiolytic-like behavior in ulcerated rodents by oral or inhaled route

BACKGROUND

Geraniol (GE) is dietary acyclic monoterpene alcohol found in essential oils from aromatic plants with therapeutic value against gastric ulcers already described.

HYPOTHESIS/PURPOSE

To assess whether oral GE accelerates gastric healing or prevents ulcer recurrence, and to evaluate the hypothesis that GE promotes antiulcer effects by the inhaled route and that promotes changes in the behavior of ulcerated rodents.

METHODS

Gastric healing effects, underlining mechanisms, and behavioral changes were measured in80% acetic acid-induced gastric ulcer model in rats receiving GE by oral (30 mg/kg) or inhaled route (1 mg/L of air/min); whereas the effects of GE to avoid ulcer recurrence was evaluated in mice submitted to 10% acetic acid plus IL-1β ulcer.

RESULTS

GE administered by both routes accelerates gastric healing, increasing mucin and GSH levels, CAT, and GST activities, and reducing MPO activity. Moreover, oral, and inhaled GE minimized ulcer recurrence reducing gastric TNF and IL-6 levels and preserving mucin levels. Interestingly, the inhalation or oral intake of GE promotes anxiolytic-like effects in ulcerated rats.

CONCLUSION

Data altogether suggest that the GE accelerates gastric healing through the strengthening of protective factors of the gastric mucosa, promoting a quality healing that reduces the recurrence of the lesion. Besides, the anxiolytic-like effect of GE may also contribute to its gastric healing action since anxiety is recognized as one of the etiologic agents of ulcers.

A collection of the etiological theories, characteristics, and observations/phenomena of peptic ulcers in existing data

In this article, we compiled 13 etiological theories, 15 characteristics, and 81 observations/phenomena of peptic ulcers, reported in reproducible, peer-reviewed studies from the literature, to reflect the historical evolution of studies on peptic ulcers and to provide a multidisciplinary view of this disease. This data was collected during the systematic review of topics on peptic ulcers including genetics, etiology, epidemiology, psychology, anatomy, neurology, bacteriology, pathology, and clinical statistics. The data curated herein was extracted via application of recently published basic theories and methodologies.

Prevalence and risk factors for gastric ulceration in pigs slaughtered at 170 kg

Oesophago-gastric ulcers (OGU) are a production and welfare problem in pigs. Stomach condition was scored for 22 551 pigs in 228 batches over a 7-month period at an abattoir in Italy processing heavy pigs for ham production. Mild or severe ulceration was observed in 20.7% of pigs, of which 13% had scar tissue. Variation between batches was high (0% to 36% prevalence of severe ulcers) and showed a significant effect of farm of origin (P<0.001). Overnight lairage increased the prevalence of mild ulcers (P<0.001), but not severe or scarred ulcers. Scarred ulcers increased in the hottest summer months. Prevalence of ulcers showed only few and weak correlations at batch level with pathologies of the pleura, lungs and liver, but a strong correlation with on-farm mortality of the batch. Analysis of farm risk factors for OGU was assessed by questionnaire with a response rate of 17% of farms. Risk factors retained in a multivariable model included a protective effect of anthelmintic treatment (risk ratio (RR)=5.1, P=0.03), increased risk in farms using Mycoplasma vaccination (RR=5.6, P=0.04) and a tendency for association with type of flooring (P=0.06). Univariable analyses also highlighted possible influences of other stress-inducing factors including lack of enrichment objects and mixing of pigs during fattening, suggesting that the role of on-farm stressors merits further investigation. It is concluded that abattoir screening of OGU in future programmes for the assessment of well-being on farm should encompass only severe lesions and scarring, and results be returned to farmers to facilitate improvement of production and welfare.

Impact of the amount of straw provided to pigs kept in intensive production conditions on the occurrence and severity of gastric ulceration at slaughter

This study examined effects of the amount of straw offered on occurrence and severity of gastric lesions in pigs kept in pens (18 pigs, 0.7 m(2)/pig) with partly slatted flooring and 10, 500 or 1000 g straw/pig/day from 30 kg live weight. The pigs had ad libitum access to dry feed. Forty-five pigs were used, three from each of 15 pens. After euthanization, the dimension of the non-glandular region of the stomach was measured. Lesions were characterized and scored. Irrespective of straw provided, 67% of the pigs showed signs of gastric pathology. Pigs provided with 500 or 1000 g straw were pooled as 'permanent access'. The proportion of pigs with ulcerations was reduced by permanent access to straw (7 vs. 33%; P<0.05), suggesting that permanent access to straw may improve animal health, and be considered as one possible strategy to limit gastric ulceration in pigs.

Mechanisms involved in the gastroprotective activity of Celtis iguanaea (Jacq.) Sargent on gastric lesions in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Celtis iguanaea (Canabaceae) is popularly known as esporão-de-galo, stands out among the medicinal plants used for treatment of gastric ulcers. In Brazil, the leaves they are used traditionally in infusion forms as an analgesic, antiasthmatic, digestive and diuretic.

AIM OF THE STUDY

The present study was aimed to investigate the antiulcer mechanisms of hexane extract Celtis iguanaea leaves (HE) in several induced-gastric ulcer and characterize its chemical composition.

MATERIALS AND METHODS

The HE was obtained by exhaustive extraction in Soxhlet apparatus. The chemical characterization of HE was performed by Electrospray Fourier transform ion cyclotron mass spectrometry (ESI FT-ICR MS) analysis. Mice were used for the evaluation of the gastroprotective activity. HE was analyzed in the HCl/ethanol, hypothermic restraint stress ulcer and acetic acid. In the investigation of the gastroprotective mechanisms of HE, were performed the amount of adhered gastric mucus, participation of the α2-adrenoceptor, nitric oxide (NO) and prostaglandins (PGs) using the HCl/ethanol-induced gastric mucosa lesion model.

RESULTS

ESI FT-ICR MS analysis of HE suggest the presence of compounds as lipids, sterol lipids, steroids glycosides and polyphenol glycosides. The oral administration of HE at doses of 100 mg/kg or 200 mg/kg was able to protect the gastric mucosa against HCl/ethanol (10 mL/kg p.o.), and HE at dose of 100mg/kg protected against hypothermic-restraint stress and acetic -induced gastric lesions. The pretreatment with Yoimbine (2mg/kg, s.c.), an antagonist α2-adrenergic, L-NAME (20mg/kg, s.c.), an inhibitor of nitric oxide synthesis or indomethacin (10mg/kg, s.c.), an inhibitor of prostaglandin production, reversed the gastroprotective activity of HE (100mg/kg, p.o.).

CONCLUSIONS

Our results suggest that the Celtis iguanaea HE exhibits gastroprotective activity in different gastric ulcer models. The mechanism of gastroprotective effect of Celtis iguanaea HE suggests the participation of mucus as well as the involvement of α2-adrenergic receptors, NO and prostaglandins. The hydroxyl-linolenic acid, linoleic acids and conjugated oxo-linoleic acids are among the phytoconstituents that were identified in the Celtis iguanaea HE.

Peptic ulcers after the Great East Japan earthquake and tsunami: possible existence of psychosocial stress ulcers in humans

BACKGROUND

Societal stress derived from an event that affects the whole society, e. g., a natural disaster, provides a unique, indirect way of determining the relationship between psychological stress and peptic ulcer disease in humans. In this study, we investigated the changing patterns of the incidence of peptic ulcers before and after the Great East Japan earthquake, which occurred on 11 March, 2011.

METHODS

Clinical data of patients with peptic ulcers were retrospectively collected during the 3 months after the earthquake (2011) from 7 major hospitals in the middle of the stricken area, and were compared with the data for the same period of the previous year (2010). The eligible subjects were classified into four groups according to Helicobacter pylori infection status and intake of nonsteroidal anti-inflammatory drugs (NSAIDs).

RESULTS

The incidence of all types of peptic ulcers was 1.5-fold increased after the earthquake, and in particular, the incidence of hemorrhagic ulcers was 2.2-fold increased; the gastric ulcer/duodenal ulcer ratio in hemorrhagic ulcers was also significantly increased (p < 0.05). Regarding the etiology of the peptic ulcers, the proportion of non-H. pylori and non-NSAID ulcers was significantly increased, from 13 % in 2010 to 24 % in 2011 after the earthquake (p < 0.05).

CONCLUSION

In addition to the increased incidence of peptic ulcers, compositional changes in the disease were observed after the Great East Japan earthquake. The significant increase in the proportion of non-H. pylori and non-NSAID ulcers after the earthquake indicated that psychological stress alone induced peptic ulcers in humans independently of H. pylori infection and NSAID intake.

Changes of ultrastructure and downregulation of heat shock protein 70 and fibroblast growth factor 2 in gastric mucosa of rats with depressive-like behaviour

OBJECTIVE

To understand the underlying mechanism of gastric symptoms in patients with depressive disorder.

METHODS

This study tested in the rat depression model evoked with chronic mild stress whether the microstructure gastric mucosa is injured using scanning electronic microscopy and transmission electronic microscopy (TEM). In addition, the expression of heat shock protein 70 (HSP70) and fibroblast growth factor 2 (FGF2) proteins in the gastric mucosa were measured by Western blotting.

RESULTS

We found that the gastric epithelial cells were ruptured and the gastric pits were widened in rats with depression. The amount of mucous granules was also reduced in the surface mucous cells. Moreover, parietal cells became active, and the secretory canaliculi were magnified. Expression of HSP70 and FGF2 was reduced in the gastric mucosa.

CONCLUSIONS

These findings suggested that gastric symptoms in rats with depressive-like behaviour were caused by the injury of the gastric mucosa, AQ1 and HSP70 and FGF2 may be key molecules in the pathogenesis.

Combination of angiotensin II receptor blockers promotes proton pump inhibitor-based healing of reflux esophagitis

BACKGROUND

Several studies have described factors associated with the failure of proton pump inhibitors (PPIs) to effect endoscopic healing of reflux esophagitis (RE), but few studies have addressed factors promoting PPI-based endoscopic healing. We performed post hoc analysis of a multicenter prospective cohort of RE patients to identify factors encouraging endoscopic healing of this disorder.

METHODS

Patients with RE received 10 or 20 mg rabeprazole for 8 weeks, and endoscopic findings before and after treatment were studied. To evaluate the effects of patient background factors on endoscopic healing, we performed multiple logistic regression analysis and determined the respective odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

A total of 454 patients who underwent endoscopy at baseline and again at week 8 were included in the analysis. After 8 weeks of treatment, improvement in endoscopic findings was observed in 94.1% (427/454) of patients, and endoscopic healing was seen in 76.7% (348/454). Multiple logistic regression analysis revealed that a combination of angiotensin II receptor blockers (ARBs) had a significant positive impact on endoscopic healing (OR 3.9, 95% CI 1.411-10.903), but no significant positive relationship was seen for other concomitant drugs such as nonsteroidal anti-inflammatory drugs and calcium channel blockers. Severe RE at baseline (OR 0.365, 95% CI 0.281-0.475) and PPI therapy prior to enrollment (OR 0.154, 95% CI 0.052-0.453) were found to have significant negative effects on endoscopic healing.

CONCLUSIONS

Concomitant use of ARBs may promote endoscopic healing of RE treated with PPIs.

Gastroprotective activity of Zanthoxylum rhoifolium Lam. in animal models

ETHNOPHARMACOLOGICAL RELEVANCE

The stem barks of Zanthoxylum rhoifolium Lam. (Rutaceae), locally known as "mamica de cadela", are popularly used in dyspepsies, stomachic, tonic, antitumoral, antipyretic and are used in treating flatulence and colic. The objective of this study was to evaluate the gastroprotective effect of the ethanolic extract of Zanthoxylum rhoifolium (EEZR) stem barks in acute gastric lesion models, investigating their possible mechanisms.

MATERIALS AND METHODS

Mice were used for the evaluation of the acute toxicity, and mice and rats to study the gastroprotective activity. The gastroprotective action of EEZR was analyzed in the absolute ethanol, HCl/ethanol and indomethacin-induced gastric lesion models in mice, hypothermic-restraint stress, and ischemia/reperfusion in rats. In the investigation of the gastroprotective mechanisms of EEZR, the participation of the NO-synthase pathway, ATP-sensitive potassium channels (K(ATP)), the levels of the non-protein sulfhydril groups (NP-SH) and the catalase activity using the ethanol-induced gastric mucosa lesion model and the quantification of the gastric mucus and the antisecretory activity through pylorus ligature model in rats were analyzed.

RESULTS

The animals did not present any signs of acute toxicity for the EEZR (up to the 4 g/kg dose, po), and it was not possible to calculate the DL(50). EEZR (125-500 mg/kg) exhibited a significant gastroprotective effect in absolute ethanol, HCl/ethanol, hypothermic-restraint stress, and ischemia/reperfusion-induced gastric lesion models. EEZR (250 and 500 mg/kg) exhibited still a gastroprotective activity in the indomethacin-induced ulcer model. Gastroprotection of EEZR was significantly decreased in pre-treated mice with l-NAME or glibenclamide, the respective nitric oxide synthase and K(ATP) channels inhibitors. Our studies revealed that EEZR (500 mg/kg) prevented the decrease of the non-protein sulfhydril groups (NP-SH) and increased the catalase levels in ethanol-treated animals. Furthermore, the extract (500 mg/kg) significantly increased the mucus production, however, the gastric secretion parameters (volume, [H(+)], pH) did not show any alteration.

CONCLUSIONS

Our results indicate that the ethanolic extract of Zanthoxylum rhoifolium exhibits a significant gastroprotection, because it inhibits the formation of gastric lesions using different models. The release of the nitric oxide, the opening of the K(ATP) channels, the participation of the non-protein sulfhydril groups (NP-SH), catalase and the increase of mucous secretion seem to be involved in the gastroprotection activity of the EEZR. Nevertheless, this activity does not seem to be related to antisecretory mechanisms.

Octreotide ameliorates gastric lesions in chronically mild stressed rats

AIM: To evaluate the effect of chronic mild stress (CMS) on the emergence of gastric ulcers and possible modulation by octreotide, a synthetic somatostatin analogue.

METHODS: Adult male Wistar rats were subjected to nine different unpredictable random stress procedures for 21 d, a multifactorial interactional animal model for CMS. Octreotide was administered daily for 21 d at two dose levels (50 and 90 μg/kg) before exposure to stress procedure. Macro- and microscopical assessments were made, in addition to quantification of plasma corticosterone and gastric mucosal inflammatory, oxidative stress, and apoptotic biomarkers.

RESULTS: Exposure to CMS elevated plasma corticosterone (28.3 ± 0.6 μg/dL, P = 0.002), an event that was accompanied by gastric lesions (6.4 ± 0.16 mm, P = 0.01) and confirmed histopathologically. Moreover, the insult elevated gastric mucosal lipid peroxides (13 ± 0.5 nmol/g tissue, P = 0.001), tumor necrosis factor-α (3008.6 ± 78.18 pg/g tissue, P < 0.001), prostaglandin E2 (117.1 ± 4.31 pg/g tissue, P = 0.002), and caspase-3 activity (2.4 ± 0.14 OD/mg protein, P = 0.002). Conversely, CMS mitigated interleukin-10 (627.9 ± 12.82 pg/g tissue, P = 0.001). Furthermore, in animals exposed to CMS, octreotide restored plasma corticosterone (61% and 71% from CMS, P = 0.002) at both dose levels. These beneficial effects were associated with a remarkable suppression of gastric lesions (38% and 9% from CMS, P = 0.01) and reversal of derangements in gastric mucosa.

CONCLUSION: The current investigation provides evidence that exposure to CMS induces gastric ulceration, which was alleviated by administration of octreotide possibly possessing antioxidant, anti-inflammatory, and anti-apoptotic actions.

Bearing grudges and physical health: relationship to smoking, cardiovascular health and ulcers

BACKGROUND

Personality traits are reported to be associated with a variety of medical comorbidities. Correlational studies report an association between 'bearing grudges' and medical conditions. We hypothesize persons reporting "bearing grudges for years" would be more likely to have medical comorbidities and test this hypothesis in an epidemiological sample.

METHODS

The National Comorbidity Survey Replication is a probability sample of the US population designed to constitute a nationally representative sample (N = 9,882). Associations were measured in odds ratios (95% CI) and adjusted using logistic regression. Confounders included: gender, age, race, and smoking status. We tested the hypothesis on 14 following medical conditions: heart disease, high blood pressure, history of heart attack, asthma, diabetes, cancer, epilepsy, arthritis, neck problems, headaches, stroke, and ulcers. Significance levels were adjusted for multiple comparisons using the Bonferoni procedure.

RESULTS

Positive and statistically significant associations were found, after adjusting for confounders and correcting for multiple comparisons, between bearing grudges and history of heart attack (odds ratio 2.1, 95% CI 1.5-2.9) and disease (1.6, 1.2-2.2); high blood pressure (1.5, 1.3-1.7), stomach ulcers (1.6, 1.3-1.9); arthritis (1.5, 1.3-1.9); back problems (1.6, 1.4-1.8); headaches (1.8, 1.6-2.1); and chronic pain (1.7, 1.4-2.1). No association was found with history of asthma, diabetes, epilepsy, allergies, stroke, and cancer.

CONCLUSIONS

In a population-based survey, bearing grudges is associated with a history of pain disorders, cardiovascular disease, and stomach ulcers. These results point to the importance of psychosomatic research in medical settings.

The multiple linkages of personality and disease

Associations between personality and health and longevity are increasingly well documented, but the causal inter-connections are often much more complex than originally anticipated. Multiple causal pathways may operate simultaneously as the individual travels an idiosyncratic route across the life-span. Therefore, a straightforward model of personality, immunity, and disease may never be established and validated, because it overlooks other key elements of the causal processes. Psychoneuroimmunology research may profit from closer integration into the broader conceptual understandings of personality and health, using a new life-span epidemiological personality approach.

Angiotensin receptor subtype mediated physiologies and behaviors: new discoveries and clinical targets

The renin-angiotensin system (RAS) mediates several classic physiologies including body water and electrolyte homeostasis, blood pressure, cyclicity of reproductive hormones and sexual behaviors, and the regulation of pituitary gland hormones. These functions appear to be mediated by the angiotensin II (AngII)/AT(1) receptor subtype system. More recently, the angiotensin IV (AngIV)/AT(4) receptor subtype system has been implicated in cognitive processing, cerebroprotection, local blood flow, stress, anxiety and depression. There is accumulating evidence to suggest an inhibitory influence by AngII acting at the AT(1) subtype, and a facilitory role by AngIV acting at the AT(4) subtype, on neuronal firing rate, long-term potentiation, associative and spatial learning, and memory. This review initially describes the biochemical pathways that permit synthesis and degradation of active angiotensin peptides and three receptor subtypes (AT(1), AT(2) and AT(4)) thus far characterized. There is vigorous debate concerning the identity of the most recently discovered receptor subtype, AT(4). Descriptions of classic and novel physiologies and behaviors controlled by the RAS are presented. This review concludes with a consideration of the emerging therapeutic applications suggested by these newly discovered functions of the RAS.

Modulation of clinical expression of plaque-induced gingivitis: effects of personality traits, social support and stress

BACKGROUND

Studies have shown an association between an acute stressful event and gingivitis. However, the possible effects of personality traits associated with stress resistance/susceptibility and current level of stress on the clinical expression of plaque-induced inflammation remain to be examined. The aim of this study was to characterize the subject-based clinical behaviour of the gingiva during experimental gingivitis in relation to personality profile, psychological stress and coping behaviour.

METHODS

Ninety-six systemically and periodontally healthy subjects (mean age: 23.6+/-1.7 years), 46 males and 50 females, non-smokers, participated in a randomized, split-mouth, localized experimental gingivitis trial. Prior to the trial, subjects were asked to complete self-administered questionnaires evaluating personality traits (Hardiness scale and Courtauld Emotional Control Scale), subjective stress (Visual Analogue Scale-Total Distress), social support (Multidimensional Scale of Perceived Social Support, MSPSS) and life events (Life Experiences Survey (LES)). The influence of psychosocial factors was investigated in the overall population as well as in two sub-populations with different inflammatory response to plaque accumulation.

RESULTS

No significant relationships were found between gingival inflammation variables and psychological measures. No significant differences were detected between subjects with different susceptibilties to plaque-associated gingivitis for any considered psychological variable. A significant association between plaque variables and LES (negative) or MSPSS (positive) was found; however, the variance explained by the model was low.

CONCLUSIONS

Differences in the current level of stress and psychosocial variables indicative of stress susceptibility do not account for variability in plaque accumulation and gingival inflammation during experimental gingivitis in young adults.

Trauma and resulting sensitization effects are modulated by psychological factors

Traumas have both immediate consequences and proactive consequences. Examples include learned helplessness, HPA-axis responsivity, gastrointestinal vulnerability to ulcer, and other correlates of anxiety disorders. Both immediate and proactive consequences may be modulated by behavioral and cognitive evolutionary evolved adaption processes, among which are forms of learning that enable 'coping'. Examples of associative and non-associative forms of coping and effects on learned helplessness, HPA-axis responsivity, and gastrointestinal vulnerability are presented. The importance of attention to behavioral contingencies in situations in which potentially traumatic events occur is emphasized as critical to understanding that it is not the physical event(s) per se that determine the immediate and long term consequences.

Cognitive activation theory of stress (CATS): from fish brains to the Olympics

The Cognitive Activation Theory of Stress (CATS) offers formal and systematic definitions of the terms and concepts used in stress research. The stress response depends on acquired expectancies to the outcome of the stimulus and the available responses. The stress response itself is an alarm, an increase in arousal necessary for performance and adequate reactions to challenges. The response is healthy and necessary for survival. Only when sustained over time may potential health risks occur. The basic rules for when stress occurs are the same across cultures and species, from fish to Olympic performance in humans. The important dimensions for health are positive expectancies of outcome (coping), control, and safety, for all individuals in all species.

Anti-stress and anti-anxiety effects of centrally acting angiotensin II AT1 receptor antagonists

The brain and the peripheral (hormonal) angiotensin II systems are stimulated during stress. Activation of brain angiotensin II AT(1) receptors is required for the stress-induced hormone secretion, including CRH, ACTH, corticoids and vasopressin, and for stimulation of the central sympathetic activity. Long-term peripheral administration of the angiotensin II AT(1) antagonist candesartan blocks not only peripheral but also brain AT(1) receptors, prevents the hormonal and sympathoadrenal response to isolation stress and prevents the formation of stress-induced gastric ulcers. The mechanisms responsible for the prevention of stress-induced ulcers by the AT(1) receptor antagonist include protection from the stress-induced ischemia and inflammation (neutrophil infiltration and increase in ICAM-1 and TNF-alpha) in the gastric mucosa and a partial blockade of the stress-induced sympathoadrenal stimulation, while the protective effect of the glucocorticoid release during stress is maintained. AT(1) receptor antagonism prevents the stress-induced decrease in cortical CRH(1) and benzodiazepine binding and is anxiolytic. Blockade of brain angiotensin II AT(1) receptors offers a novel therapeutic opportunity for the treatment of anxiety and other stress-related disorders.

Mechanisms of action of leptin in preventing gastric ulcer

AIM: To investigate the effects of leptin (1-20 μg/kg) on acidified ethanol (AE)- and indomethacin (Indo)-induced gastric lesions in rats and compare it with ranitidine, lanso-prazole, and omeprazole and to determine its mechanisms of actions.

METHODS: Gastric ulcers, which were approximately 1 mm in width, formed in the glandular portion of the gastric mucosa produced by oral administration of either AE or Indo were taken as ulcer index. The inhibitory effect of subcutaneous administration of leptin, two proton pump inhibitors (PPIs) lansoprazole and omeprazole, or H₂-receptor antagonist ranitidine 30 min before AE or Indo was evaluated. A radioimmunoassay was used to determine the PGE₂ concentration in the homogenate of the glandular portion of the stomach. We performed histological study of the glandular stomach for the evaluation of total, acidic, and sulfated mucus content.

RESULTS: Subcutaneous administration of leptin, two PPIs lansoprazole and omeprazole or H₂-receptor antagonist ranitidine 30 min before AE or Indo produced a dose-dependent and reproducible inhibition of gastric ulcers (GUs). This inhibition was found to be more potent than other antagonists used. In N^G-nitro L-arginine methyl ester (L-NAME)-pretreated animals, the ulcer prevention ability of leptin in AE-induced ulcer was significantly reduced, compared to rats without L-NAME pretreatment. However, the ulcer prevention ability of leptin was not altered by L-NAME treatment in Indo-induced ulcers. Leptin produced a dose-dependent increase in PGE₂ level in the gastric glandular tissues. Leptin also increased mucus secretion.

CONCLUSION: The results of the present study show that leptin inhibits GU formation by AE or Indo in a dose-dependent and reproducible manner in rats. The results also suggest that leptin prevents ulcer formation by increasing the activities of the cyclo-oxygenase and/or nitric oxide pathways and by increasing mucus secretion.

An acute stressor enhances sensitivity to a chemical irritant and increases 51CrEDTA permeability of the colon in adult rats

We investigated the effect of prior acute stress on colonic permeability induced by a chemical irritant known to induce symptoms similar to inflammatory bowel disease in rodents. Adult male rats (n = 12) were stressed by a single session of ten unpredictable, uncontrollable foot shocks, and half were home cage controls (n = 12). Twenty-nine days later, half of each treatment group was exposed to 4% DSS (dextran sulphate sodium) solution in their drinking water for 48 hours while half received pure water over two periods separated by 17 days. After food deprivation overnight and light isoflurane anaesthesia the following morning, the animals were given a colonic infusion of 2000 nCi (nanocurie) 51CrEDTA (51Cr-labelled ethylenediaminetetraacetic acid) and then placed individually in metabolic cages for a six hours continuous urine collection. Radioactivity in urine was measured by a gamma counter and percentage recovery of 51CrEDTA calculated as an indicator of colonic mucosal permeability. Results concluded that pre-shocked animals exposed to DSS showed significantly higher mucosal permeability than the pre-shocked animals given water, and the non-shocked animals given either DSS or water. Pre-shock in combination with two exposures to a chemical irritant separated by 17 days had a pronounced effect on colonic permeability, indicating that stress should be considered a possible initiating or contributory factor to increased intestinal permeability related to a mucosal challenge.

Analysis of the cold-water restraint procedure in gastric ulceration and body temperature

Gastric mucosal injury induced by body restraint can be enhanced when combined with cold-water immersion. Based on this fact, the present study had two main purposes: (i) to examine the contribution of each of these two forms of stress on the development of gastric ulceration and regulation of body temperature and (ii) to investigate the importance of the animal's consciousness on gastric ulceration induced by the cold-water restraint. Independent groups of animals were exposed for 3 h to one of the following stressful treatments: body restraint plus cold-water (20+1 degrees C) immersion, body restraint alone or cold-water immersion alone. Control animals were not exposed to any form of stress. Half of the animals submitted to each of the four treatments were anesthetized with thionembutal (35 mg/kg), whereas the other half was injected with saline. Results indicated that body restraint alone was not sufficient to induce gastric ulceration or changes in body temperature. On the other hand, cold-water exposure, either alone or in conjunction with body restraint, induced the same amount of stomach erosions and hypothermia. Therefore, it appears that body restraint does not play an important role on gastric ulceration induced by the cold-water restraint procedure. Present results also indicated that conscious and anesthetized animals immersed in cold water presented robust gastric ulceration and a marked drop in body temperature. However, conscious animals developed more severe gastric damage in comparison to anesthetized animals although both groups presented the same degree of hypothermia. These findings suggest that hypothermia resulting from cold-water exposure has a deleterious effect on gastric ulceration but the animal's conscious activity during the cold-water immersion increases the severity of gastric mucosal damage. It is concluded that cold-water restraint is a useful procedure for the study of the underlying mechanisms involved in stress-induced ulceration.

Brain angiotensin II, an important stress hormone: regulatory sites and therapeutic opportunities

The presence of a brain Angiotensin II (Ang II) system, separated from and physiologically integrated with the peripheral, circulating renin-angiotensin system, is firmly established. Ang II is made in the brain and activates specific brain AT(1) receptors to regulate thirst and fluid metabolism. Some AT(1) receptors are located outside the blood-brain barrier and are sensitive to brain and circulating Ang II. Other AT(1) receptors, located inside the blood-brain barrier, respond to stimulation by Ang II of brain origin. AT(1) receptors in the subfornical organ, the hypothalamic paraventricular nucleus (PVN), and the median eminence are involved in the regulation of the stress response. In particular, AT(1) receptors in the PVN are under glucocorticoid control and regulate corticotrophin-releasing hormone (CRH) formation and release. In the PVN, restraint elicits a fast increase in AT(1) receptor mRNA expression. The expression of paraventricular AT(1) receptors is increased during repeated restraint and after 24 h of isolation stress, and their stimulation is essential for the hypothalamic-pituitary-adrenal axis activation, the hallmark of the stress response. Peripheral administration of an AT(1) receptor antagonist blocks peripheral and brain AT(1) receptors, prevents the sympathoadrenal and hormonal response to isolation stress, and prevents the gastric stress ulcers that are a characteristic consequence of cold-restraint stress. This evidence indicates that pharmacologic inhibition of the peripheral and brain Ang II system by AT(1) receptor blockade has a place in the prevention and treatment of stress-related disorders.

Anti-inflammatory effects of angiotensin II AT1 receptor antagonism prevent stress-induced gastric injury

Stress reduces gastric blood flow and produces acute gastric mucosal lesions. We studied the role of angiotensin II in gastric blood flow and gastric ulceration during stress. Spontaneously hypertensive rats were pretreated for 14 days with the AT1 receptor antagonist candesartan before cold-restraint stress. AT1 receptors were localized in the endothelium of arteries in the gastric mucosa and in all gastric layers. AT1 blockade increased gastric blood flow by 40-50%, prevented gastric ulcer formation by 70-80% after cold-restraint stress, reduced the increase in adrenomedullary epinephrine and tyrosine hydroxylase mRNA without preventing the stress-induced increase in adrenal corticosterone, decreased the stress-induced expression of TNF-alpha and that of the adhesion protein ICAM-1 in arterial endothelium, decreased the neutrophil infiltration in the gastric mucosa, and decreased the gastric content of PGE2. AT1 receptor blockers prevent stress-induced ulcerations by a combination of gastric blood flow protection, decreased sympathoadrenal activation, and anti-inflammatory effects (with reduction in TNF-alpha and ICAM-1 expression leading to reduced neutrophil infiltration) while maintaining the protective glucocorticoid effects and PGE2 release. Angiotensin II has a crucial role, through stimulation of AT1 receptors, in the production and progression of stress-induced gastric injury, and AT1 receptor antagonists could be of therapeutic benefit.

A study of the effects of restraint stress on colitis induced by dextran sulphate sodium in singly housed rats

The inflammatory bowel diseases (Crohn's disease and ulcerative colitis) are multifactorial diseases. Clinical reports indicate that emotional stress may contribute to the onset, progression and remission of these diseases. Using an experimental animal model of ulcerative colitis, the effect of stress on the development of and recovery from symptoms was studied prospectively. Singly housed rats received 4 percent dextran sulphate sodium orally until fecal blood was detected, indicating the presence of colonic erosions. Tap water was then administered until there were no signs of fecal blood. Two hours of restraint stress were administered daily over four successive days, either prior to or after the induction of colitis. Latencies in days to symptom development and recovery were compared to an unstressed group. Daily measures of fluid-intake, body-weight, and hemoglobulin in feces were made.

RESULTS

Rats exposed to restraint stress procedures prior to induction of colitis had shorter latencies to development of symptoms. There was no significant difference in latency to recovery. The amount of fluid-intake did not significantly differ between groups, nor did the groups differ in body-weight.

CONCLUSION

There is an effect of stress on the latency to develop colitis induced by dextran sulphate sodium. This preliminary study suggests that the impact of stress may be one factor underlying the emergence of ulcerative colitis.

Mental health insurance claims among spouses of frequent business travellers

OBJECTIVES

Following up on two earlier publications showing increased psychological stress and psychosocial effects of travel on the business travellers this study investigated the health of spouses of business travellers.

METHODS

Medical claims of spouses of Washington DC World Bank staff participating in the medical insurance programme in 1997-8 were reviewed. Only the first of each diagnosis with the ninth revision of the international classification of diseases (ICD-9) recorded for each person was included in this analysis. The claims were grouped into 28 diagnostic categories and subcategories.

RESULTS

There were almost twice as many women as men among the 4630 identified spouses. Overall, male and female spouses of travellers filed claims for medical treatment at about a 16% higher rate than spouses of non-travellers. As hypothesised, a higher rate for psychological treatment was found in the spouses of international business travellers compared with non-travellers (men standardised rate ratios (RR)=1.55; women RR=1.37). For stress related psychological disorders the rates tripled for both female and male spouses of frequent travellers (>or= four missions/year) compared with those of non-travelling employees. An increased rate of claims among spouses of travellers versus non-travellers was also found for treatment for certain other diagnostic groups. Of these, diseases of the skin (men RR=2.93; women RR=1.41) and intestinal diseases (men RR=1.31; women RR=1.47) may have some association with the spouses' travel, whereas others, such as malignant neoplasms (men RR=1.97; women RR=0.79) are less likely to have such a relation.

CONCLUSION

The previously identified pattern of increased psychological disorders among business travellers is mirrored among their spouses. This finding underscores the permeable boundary between family relations and working life which earlier studies suggested, and it emphasises the need for concern within institutions and strategies for prevention.

Stressor controllability and learned helplessness research in the United States: sensitization and fatigue processes

Recent work in the learned helplessness paradigm suggests that neuronal sensitization and fatigue processes are critical to producing the behavioral impairment that follows prolonged exposure to an unsignaled inescapable stressor such as a series of electric tail shocks. Here we discuss how an interaction between serotonin (5-HT) and corticosterone (CORT) sensitizes GABA neurons early in the pretreatment session with inescapable shock. We propose that this process eventually depletes GABA, thus removing an important form of inhibition on excitatory glutamate transmission in the amygdala, hippocampus, and frontal cortex. When rats are re-exposed to shock during shuttle-escape testing 24 hrs later, the loss of inhibition (as well as other excitatory effects) results in unregulated excitation of glutamate neurons. This state of neuronal over-excitation rapidly compromises metabolic homeostasis. Metabolic fatigue results in compensatory inhibition by the nucleoside adenosine, which regulates neuronal excitation with respect to energy availability. The exceptionally potent form of inhibition associated with adenosine receptor activation yields important neuroprotective benefits under conditions of metabolic failure, but also precludes the processing of information in fatigued neurons. The substrates of adaptive behavior are removed; performance deficits ensue.

The effects of uncontrollable, unpredictable aversive and appetitive events: similar effects warrant similar, but not identical, explanations?

Exposure to uncontrollable, unpredictable appetitive events produces a variety of cognitive debilitations and vegetative changes, as does exposure to uncontrollable, unpredictable aversive events. Similarities include impaired escape from aversive events, impaired discrimination, finicky consumption, analgesia, and body weight loss. However, in stark contrast, uncontrollable aversive stress causes reduced motor activity where as similar appetitive treatment does not; aversively induced debilitation is causally related to energy regulation, whereas the appetitively induced effects are not. Parallel mechanisms are suggested to explain these effects in terms of a revised anxiety account of the aversive effects, and a frustration account of the appetitive effects. Finally, factors likely to limit important research to resolve the many remaining issues are identified: negative presentation of animal research, political decision making, and ignorance and fear in committees which review the ethics of research.

On learned helplessness

"Learned helplessness" and its Pavlovian analog, learned irrelevance, are phenomena thought integral to understanding depression, PTSD, psychosomatic vulnerability, and a variety of diseases and immune disorders. The origin and development of research on learned helplessness is briefly overviewed with attention to the reasons for the controversy that surrounds the study of learned helplessness and derived physiological, psychological, and behavioral phenomena. The need to remedy past focus on American research and English language journals in this area is noted. The heuristic value as well as the wide ranging empirical value of the research domain is lauded. The meretricious emerging social and legal barriers to this research are noted to be unrealistic and unfortunate.

Is there a role for psychology in ulcer disease?

The discovery of the importance of bacterial factors in the etiology of ulcer disease has led to a neglect of psychological factors. However, both earlier theoretical and empirical approaches implicating these factors are supported by more recent studies, both epidemiological and experimental. While not ignoring the unquestioned role of Helicobacter, it is important for future research to recognize the multi-factorial nature of ulcer disease by which several factors, including stress, bacteria and non-steroid antiinflammatory drugs, may interact to drive a pre-pathology (erosions or ulcerations) to a pathological state (ulcer). Calls for general eradication programs should be cautioned in the light of possible unwanted side effects.