Neurobiology of brain-gut interactions. Implications for ulcer disease

The influence of family support during endoscopic submucosal dissection on patient's anxiety

Background

Psychological problems may promote peptic ulcers. Ulcer-like wounds can be formed after gastric endoscopic submucosal dissection (ESD). The influence of family support on the healing of gastric ESD-induced ulcers remains largely undetermined.

Objective

In the present study, we aimed to assess the Hospital Anxiety and Depression Scale (HADS) scores and the incidence of post-ESD complications in patients with family support in the care process and those in the non-relative group.

Materials and methods

A total of 191 patients aged between 30 and 70 years who received gastric ESD were evaluated with the Chinese version of HADS. Differences in depression and anxiety between the two groups were compared using the chi-square test and t-test. Multivariable logistic regression models were used to examine whether anxiety and depression were the risk factors for post-ESD complications.

Results

The mean values of HADS-A (4.61 ± 2.89 vs. 5.56 ± 3.07, p = 0.042) and HADS-D (4.14 ± 3.03 vs. 4.97 ± 2.61, p = 0.048) scores were significantly lower in patients with accompanying relatives compared with those in the non-relative group. Besides, through the pre-ESD and post-ESD self-contrast, the scores of anxiety and depression in the relative-group were 0.57 and 0.56, respectively (p < 0.001), while those in the non-relative group were increased by 1.43 and 1.49, respectively (p < 0.001). Multivariable logistic regression analysis revealed that HADS-A, HADS-D scores, and age were significantly correlated with post-ESD abdominal pain (P < 0.05).

Conclusions

The occurrence and degree of adverse emotions such as psychological anxiety and depression in patients who received gastric ESD with accompanying relatives during hospitalization may were reduced, and the incidence of gastric post-ESD abdominal pain may was also decreased.

Research on mechanism of charred hawthorn on digestive through modulating "brain-gut" axis and gut flora

ETHNOPHARMACOLOGICAL RELEVANCE

Hawthorn is a traditional Chinese medicine for high-calorie-diet-induced dyspepsia (HC-DID) for thousands of years old. Based on traditional Chinese medicine (TCM) theory and clinical and non-clinical trials, its stir-frying processed product, charred hawthorn, possesses better effect. At present, most research mainly focuses on chemical constituents of hawthorn before and after stir-frying process, but there is no relevant action-mechanism study about fragrant odor promoting HC-DID during the stir-frying process of the hawthorn.

AIM OF THE STUDY

The purpose of the present study is to research on mechanism of hawthorn decoction coupled with odor of charred hawthorn on digestive in rats with HC-DID.

MATERIALS AND METHODS

The SPF Kunming (KM) mice and Sprague Dawley (SD) rats were randomly divided into 7 groups: control group, model group, cisapride group, hawthorn group (HT), charred hawthorn group (CHT), odor of charred hawthorn (OCHT), CHT + OCHT group. The rats were modeled as HC-DID, whose treatment by intragastric administration and odor administration. Obvious symptoms of HC-DID were observed. Gastrointestinal motility were detected. Histopathology was performed in hypothalamus and gastrointestinal tract. Related brain-gut peptides were assayed in serum, hypothalamus and gastrointestinal tract. Illumina Miseq platform was used for 16S rDNA high-throughput sequencing to detect the intestinal flora structure of the caecum of rats.

RESULTS

Traditional Chinese medicine decoction of hawthorn (HT and CHT) regulated the body weight, food intake, gastrointestinal motility and abnormal secretion of brain-gut peptides in rats with HC-DID, and the odor of charred hawthorn also had good curative effect for it. Moreover, the intestinal dysbiosis was induced by high-calorie diet in rats with dyspepsia, and hawthorn decoction could ease this trend.

CONCLUSION

The above study showed that hawthorn decoction coupled with the odor of charred hawthorn effectively alleviate HC-DID in rats by regulating the "Brain-Gut" axis and gut flora. Odor treatment of hawthorn could be a potential therapeutic approach for HC-DID.

The very model of a modern etiology: a biopsychosocial view of peptic ulcer

OBJECTIVE

Research on ulcer psychosomatics has plummeted since the early 1970s, to the applause of many who argue that ulcer is simply an infectious disease. The purpose of this article is to discuss the relevance of ulcer psychogenesis in the age of Helicobacter pylori.

METHODS

A critical literature review was conducted.

RESULTS

There is a substantial and methodologically sound body of prospective studies linking stress with the onset and course of peptic ulcer. Psychosocial factors can be estimated to contribute to 30% to 65% of ulcers, whether related to nonsteroidal antiinflammatory drugs, H. pylori, or neither. The observed association between stress and ulcer is accounted for, in part, by recall bias, misreported diagnoses, and confounding by low socioeconomic status (a source of stress and of ulcer risk factors, such as H. pylori and on-the-job exertion) and by distressing medical conditions (which lead to use of nonsteroidal antiinflammatory drugs). Of the residual, true association, a substantial proportion is accounted for by mediation by health risk behaviors, such as smoking, sleeplessness, irregular meals, heavy drinking, and, again, nonsteroidal antiinflammatory drugs. The remainder results from psychophysiologic mechanisms that probably include increased duodenal acid load, the effects of hypothalamic-pituitary-adrenal axis activation on healing, altered blood flow, and impairment of gastroduodenal mucosal defenses.

CONCLUSIONS

Peptic ulcer is a valuable model for understanding the interactions among psychosocial, socioeconomic, behavioral, and infectious factors in causing disease. The discovery of H. pylori may serve, paradoxically, as a stimulus to researchers for whom the concepts of psychology and infection are not necessarily a contradiction in terms.

The relationship of psychiatric illness with gastrointestinal disease

Higher rates of psychiatric comorbidity as well as more impaired psychosocial adjustment occur with the functional bowel disorders and are particularly high in self-selected referral patients compared with community populations. Reciprocally, some studies show higher rates of functional bowel disturbances in patients with psychiatric diagnoses. Remaining alert for and addressing coexisting psychiatric illness will enhance treatment outcome (increased patient compliance, functioning, and satisfaction). Additionally, psychological factors affect the clinical expression of structural disease. Resetting treatment goals from cure to coping with chronic illness and setting personal limits are important.

Nitric oxide inhibition intensifies cold-restraint induced gastric ulcers in rats

Treatment 20 min beforehand with an inhibitor of nitric oxide (NO) synthesis NW-nitro-1-arginine methyl ester (L-NAME) (12.5, 25, 50 or 100 mg/kg, s.c.), dose-dependently intensified gastric glandular mucosal ulceration produced by cold-restraint stress. Hexamethonium (20 mg/kg) or atropine (1 mg/kg) pretreatment s.c. 20 min before stress strongly antagonised stress-evoked ulceration, as well as the ulcer-potentiating effects of L-NAME when either cholinoceptor antagonist was given concurrently with the NO inhibitor. Stress-induced mast cell degranulation was not worsened by L-NAME pretreatment. The findings suggest that NO could confer partial protection against stress-induced gastric ulcer formation; its activity is triggered off by the ulcerogenic mechanism of stress.

Rôle of psychosomatic factors in peptic ulcer disease

Evidence indicates that a link between peptic ulcer disease (PUD) and selected psychosomatic factors may exist. A series of 70 consecutive male and female adult patients were categorized by peptic symptoms and divided into four groups: a) controls; b) gastric ulcer (GU); c) duodenal ulcer (DU); and d) chronic non-ulcer dyspepsia (CNUD). All patients were interviewed and asked to answer a questionnaire that included demographics, medical history and the incidence of negative life events. A decreased level of activity was a predominant finding in GU, DU and CNUD patients. Family history of PUD may be correlated with CNUD. Of interest was the finding that DU and CNUD patients presented a higher incidence of negative life events when compared to the other study groups. Negative life events that produce considerable stress may predispose to peptic symptoms in certain patients.

CNS effects on gastric functions: from clinical observations to peptidergic brain-gut interactions

Clinical observations as early as the last century pointed to the stomach's link to the brain. Animal studies in this century have given us detailed information about the neuroanatomical and neurophysiological basis of brain-gut interactions. Psychological stress models and stereotaxic brain procedures have been important tools in gaining this information. During the last 10 years, there has been much focus on the effects of neuropeptides on gastric functions. Several CNS-peptides have indeed been shown to influence multiple gastric functions such as: acid secretion, bicarbonate secretion, mucus secretion, motility, blood flow and prostaglandin synthesis. Accordingly, direct CNS-application of these peptides also influences the development of gastric erosions during experimental stress procedures.

The role of psychological factors in gastrointestinal conditions. A review pertinent to DSM-IV

The authors reviewed the literature to assess the relationship between psychological factors and gastrointestinal conditions. The conditions that were found to be more relevant and worthy of future investigation were nonulcerative dyspepsia, inflammatory bowel disease (regional enteritis), and irritable bowel syndrome. The pertinent findings suggest that an important link exists between psychological factors and gastroenterological disorders, which supports the need for modification of the DSM-III-R's diagnostic category, "Psychological Factors Affecting Physical Condition." In concert with a subcommittee addressing other organ systems and psychological factors, the authors conclude that a diagnostic approach with greater utility would be useful for both researchers and clinicians. A conceptual framework as proposed in DSM-IV could also advance knowledge of psychological factors and their contribution or role in the etiology, perpetuation, and exacerbation of certain gastrointestinal conditions.

Fluoxetine pretreatment potentiates intracisternal TRH analogue-stimulated gastric acid secretion in rats

Central injection of TRH or its metabolically stable analogue RX 77368 has been demonstrated to produce a vagal-dependent stimulation in gastric acid secretion. Accumulating evidence exists regarding the interaction of serotonin (5HT) with TRH containing neuronal systems. This study was performed to assess the effect of pretreatment with the 5HT uptake inhibitor fluoxetine on the TRH analogue-induced gastric acid secretory response. Systemic fluoxetine (30 mumol/kg, i.v.) produced a 43-85% increase in the intracisternal RX 77368 (78-780 pmol)-induced gastric acid output, while not affecting the basal acid response. The acid response to a lower dose of RX 77368 (26 pmol) was not altered. In addition, intracisternal fluoxetine (180 nmol) produced a 71% augmentation of the acid secretory response of i.c. RX 77368 (260 pmol). Intracisternal injection of lower doses (60, 120 nmol), or intravenous injection of 180 nmol of fluoxetine was ineffective in altering the intracisternal RX 77368-induced acid response. Pretreatment with the noradrenergic or dopaminergic uptake inhibitor desipramine or GBR 12909 did not alter the RX 77368-stimulated gastric acid secretory response. The results show that fluoxetine pretreatment potentiates the effect of intracisternal RX 77368 on acid secretion. The effect appears to be impulse dependent, and central sites of action are involved. The data suggest an interaction of synaptic serotonin with a RX 77368-elicited event (activation of TRH receptors, second messenger systems and/or firing of the motor vagus) results in potentiation of the RX 77368-induced gastric response.

The neurobiology of stress ulcers

We have reviewed the neurobiology of stress ulcers from animal models to potential pharmacotherapeutic mechanisms. The evidence strongly supports the hypothesis that certain stress-related gastric lesions are 'brain-driven' events which may be more effectively managed through central manipulations than by altering local, gastric factors. Recent advances in the use of anxiolytic and antidepressant drugs in the management of stress-related gastric mucosal injury further supports the contention that a brain-gut axis, which may have nervous, peptidergic and classic monoaminergic components, modulates the intricate and complicated pattern of communication between the brain and the stomach. Delineation of the precise pathways which make up this communication as well as their manipulation by various pharmacological agents will be the focus of future research endeavour.

Hymenolepis diminuta: changes in the levels of certain intestinal regulatory peptides in infected C57 mice

The levels of 10 regulatory peptides in acid-alcohol extracts of three regions of the small intestine (0-20%, 30-60%, and 70-100%, with respect to distance from the pylorus) have been monitored radioimmunometrically in sham-infected male (6-8 week old) C57 mice and mice given a 5-cysticercoid infection of the rat tapeworm Hymenolepis diminuta and autopsied 10 days postprimary infection and 5 days postsecondary infection (administered 28 days postprimary infection). The regulatory peptides examined were gastrin, gastrin-releasing peptide (GRP), glucagon (= enteroglucagon), motilin, neurotensin (NT), pancreatic polypeptide (PP), peptide histidine isoleucine (PHI), somatostatin (SRIF), substance P (SP), and vasoactive intestinal peptide (VIP). Statistical analyses revealed significant deviations from control values of five of the peptides (enteroglucagon and SP, both elevated; NT, PHI and VIP, all lowered) in intestinal tissue from infected mice; measurement of the same peptides in colonic extracts revealed no significant differences between infected and sham-infected mice. Parallel changes in peptide levels between normal infected and immunosuppressed infected mice were not evident, although elevations in the tissue levels of enteroglucagon and SP were found in infected Wistar rats (normal host). Results are discussed with respect to a peptidergic involvement in the pathology and host immune response to an intestinal tapeworm.

The role of the hypothalamus and dorsal vagal complex in gastrointestinal function and pathophysiology

A foregone conclusion is that central neural and endocrine control of gastrointestinal functions is based on a complex array of interconnecting brain structures, neurochemical systems, and hormonal modulators. As might be expected, a considerable degree of redundancy is seen not only in the manner in which certain brain structures appear to participate in the regulation of GI functions, but also in the extent to which certain neurotransmitters or brain-gut peptides, when injected centrally, alter these functions. Despite the seemingly ambiguous nature of brain-gut interactions, a picture is beginning to unfold that suggests that GI properties are based on certain reflexes (e.g., vago-vagal). These reflexes, in turn, appear to be influenced by brain structures in a hierarchical manner, not all that dissimilar to the system described by Papez and expanded on by MacLean several years ago. For example, the perceptual or cognitive aspects of both external and internal stimuli are monitored at various brain levels, but obviously higher cortical processes are intimately involved. Aversive events provide sensory information, which is integrated primarily by the limbic system (e.g., amygdala) and translated into the expression of emotional behavior and associated autonomic response patterns. Various hypothalamic structures, in turn, appear most strongly to influence physiological changes associated with aversive events by virtue of the direct connections to the autonomic and endocrine systems. Ultimately, the visceral outcome can be seen as being based on the integrated convergence of information from cortical, limbic, and hypothalamic structures onto medullary nerve nuclei as well as other efferent systems. With respect to animal models of neurogenic or stress ulcer, activity of the dorsal vagal complex and vagal efferents appears to be the final common pathway for pathologic changes in the gut.

Acid and barriers. Current research and future developments for peptic ulcer therapy

Medical therapy for peptic ulcer disease has been targeted at inhibiting acid secretion based on the belief that ulcers occur due to an imbalance between aggressive and protective factors. New antisecretory agents are unlikely to show any dramatic improvement over the success and safety of histamine H2 receptor antagonists or the recently introduced H+K+ATPase proton pump antagonist omeprazole. The development of specific muscarinic M3 and gastrin receptor antagonists will provide useful agents to suppress acid and pepsinogen secretion by alternative means and may prevent the associated hypergastrinaemia seen with anti-secretory therapy. Enhancement of mucosal defence by site protective agents will be based on a better understanding of the vascular and immune factors involved in maintaining mucosal integrity and the growth factors that regulate wound healing. Molecular techniques are likely to produce the 'model anti-ulcer' agent which will effectively inhibit acid secretion and also enhance wound healing thus providing a cure for this chronic disease.