Adaptive cytoprotection and the brain-gut axis

The effect of apelin-13 on gastric ischemia/reperfusion injury: the roles of sensory nerves and vagus nerve

Apelin is a peptide that plays a role in physiological processes such as angiogenesis, apoptosis, and proliferation. The aim of this study was to investigate the role of capsaicin-sensitive afferent neurons and vagus in the effect of apelin against ischemia/reperfusion (I/R) injury. The experimental groups were (1) control, (2) I/R, (3) apelin + I/R, (4) vagotomy + I/R, (5) vagotomy + apelin + I/R, (6) capsaicin + I/R, (7) capsaicin + apelin + I/R, (8) lorglumide + I/R, and (9) lorglumide + apelin + I/R. To test the potential gastroprotective effect of apelin-13, apelin-13 (2 mg/kg i.v.) was administered just before both ischemia and reperfusion. A vagotomy was performed 1 week before I/R in the vagotomized groups; capsaicin (125 mg/kg s.c.) was administrated 2 weeks before I/R in the capsaicin-treated groups and lorglumide (5 mg/kg i.p.) was administered 30 min before I/R in the lorglumide-treated groups. After I/R, a variety parameters in gastric tissue were analyzed. cfos expression was determined in brainstem samples. In the I/R group, the lesion index, myeloperoxidase activity, lipid peroxidation, nitric oxide, and tumor necrosis factor-α increased, and mucosal blood flow, prostaglandin-E₂, and calcitonin gene related peptide decreased. Apelin prevented the damaging effects of I/R and increased cfos expression in brainstem areas. Vagotomy, capsaicin, and lorglumide largely eliminated the gastroprotective effects of apelin-13. This study showed that sensory nerves and the vagus play regulatory roles in apelin-induced gastroprotection. Cholecystokinin may play a role in the effect of apelin through sensory neurons.

Circulating IL-6 and neopterin concentrations link cell-mediated immunity and tumor stage in patients with gastro-intestinal adenocarcinoma: relevance to the pituitary-adrenal axis and pituitary-thyroid axis

Although cortisol is a powerful modulator of the immune system and inhibits production of pro-inflammatory cytokines, adrenocorticotropic hormone (ACTH) levels do not correspond to the chronically elevated concentrations of cortisol in cancer patients. Thyroid stimulating hormone (TSH) has been shown to have an effect on immunological functions. Actually it is not known whether cortisol, TSH and IL-6 have an effect on tumor progression via modulation of cell mediated immunity in patients with gastrointestinal carcinoma. Sixty-seven gastrointestinal cancer patients and 42 cancer-free subjects with cholelithiasis as the control group, were included in the study. Serum ACTH, cortisol, TSH, thyroid hormones, IL-6, IL-10 and neopterin levels were measured. Diagnosis and pathological staging were confirmed by surgical intervention. Cortisol levels were correlated with IL-6 in cancer patients. In addition to elevated neopterin values, linear regression analysis revealed that serum neopterin was associated more strongly with the increase of cortisol rather than IL-6 levels in advanced stage carcinoma. Furthermore, neopterin also correlated with IL-6, IL-10, cortisol and TSH levels in advanced carcinoma cases. These data indicated that cortisol, IL-6 and neopterin values of cancer patients were influenced by the tumor presence and progression.

Functional dyspepsia and brain-gut peptides

Functional dyspepsia (FD) is a frequently occurring gastrointestinal disorder, but its etiology and pathogenesis are still unclear because it is associated with multiple factors. As a typically physical and psychological disease, the role of psychological factors in the pathogenesis of FD involves the brain-gut axis, mainly abnormal stimulation processing by the central nervous system and abnormal levels of brain-gut peptides. Brain-gut peptides are the molecular basis of the action of the brain-gut axis, and the brain-gut axis affects the occurrence of FD by regulating the levels of brain-gut peptides. So far, 15 brain-gut peptides associated with FD have been found, which are predominantly expressed in the hypothalamus, medulla oblongata, spinal cord and gastrointestinal mucosa. The aim of this study is to clarify the relationship between brain-gut peptide levels and the occurrence of FD based on brain-gut peptide in terms of their secretion and mechanisms of action.

Role of psychological factors in pathogenesis of ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory disease of the colon of unknown etiology. Multiple factors induce the occurrence and development of UC. Among these factors, psychological factors play an important role. As psychoneuroimmunology concept is gradually being accepted, it is currently believed that emotion can affect immune function through the nervous system. Recent studies suggest that psychological stress can be involved in alterations in intestinal inflammation by changing brain-gut axis function, exciting vegetative nerve, releasing neurotransmitters and altering bacterial-mucosal interactions. This paper reviews recent advances in understanding the role of psychological factors in the pathogenesis of UC and emphasizes the ways for the development of therapeutic psychological interventions.

Moderate ethanol ingestion and cardiovascular protection: from epidemiologic associations to cellular mechanisms

While ethanol intake at high levels (3-4 or more drinks), either in acute (occasional binge drinking) or chronic (daily) settings, increases the risk for myocardial infarction and stroke, an inverse relationship between regular consumption of alcoholic beverages at light to moderate levels (1-2 drinks per day) and cardiovascular risk has been consistently noted in a large number of epidemiologic studies. Although initially attributed to polyphenolic antioxidants in red wine, subsequent work has established that the ethanol component contributes to the beneficial effects associated with moderate intake of alcoholic beverages regardless of type (red versus white wine, beer, spirits). Concerns have been raised with regard to interpretation of epidemiologic evidence for this association including heterogeneity of the reference groups examined in many studies, different lifestyles of moderate drinkers versus abstainers, and favorable risk profiles in moderate drinkers. However, better controlled epidemiologic studies and especially work conducted in animal models and cell culture systems have substantiated this association and clearly established a cause and effect relationship between alcohol consumption and reductions in tissue injury induced by ischemia/reperfusion (I/R), respectively. The aims of this review are to summarize the epidemiologic evidence supporting the effectiveness of ethanol ingestion in reducing the likelihood of adverse cardiovascular events such as myocardial infarction and ischemic stroke, even in patients with co-existing risk factors, to discuss the ideal quantities, drinking patterns, and types of alcoholic beverages that confer protective effects in the cardiovascular system, and to review the findings of recent experimental studies directed at uncovering the mechanisms that underlie the cardiovascular protective effects of antecedent ethanol ingestion. Mechanistic interrogation of the signaling pathways invoked by antecedent ethanol ingestion may point the way towards development of new therapeutic approaches that mimic the powerful protective effects of socially relevant alcohol intake to limit I/R injury, but minimize the negative psychosocial impact and pathologic outcomes that also accompany consumption of ethanol.