Reactive changes of gastric mucosa and reduction of desacyl grelin in rat brain due to psychoemotional stress

BACKGROUND: The work is devoted to the analysis of the elements the reactivity of grelin system in the model of psychogenic stress. In recent years, it has been shown that the ghrelin brain system is not limited only to the regulation of energy balance and eating behavior. Along with other peptide regulatory systems, it plays an important role in the mechanisms of stress, reward and addiction. Therefore, the elements of this system should be considered primarily as molecular targets of pharmacological action in order to correct the states of addiction and post-stress disorders. MATERIALS AND METHODS: To produce psychoemotional stress, we used an acute single traumatic situation in male Wistar rats. The animals were placed in the tiger python, one animal died as a result of its nutritional needs, the rest of the rats experienced the death of a partner. One week after exposure to python, the animals were decapitated, and the brain structures were isolated. Aliquots of the brain structures suspensions were examined for the content of desacyl ghrelin (DAG) using a highly sensitive enzyme-linked immunosorbent assay (ELISA). In another group, rats were decapitated on the 4th day after exposure to python, stomachs were removed, which were fixed in 10% formalin solution. In horizontal paraffin sections of the gastric mucosa, after staining with hematoxylin and eosin, the heights of superficial and dimple mucous cells, the height of the dimple stroma, the area of superficial, dimple mucocytes and stroma of the dimples, and the number of dead mucocytes were calculated. To clarify the differentiation of epithelial cells, they were stained with alcian blue RESULTS: DAG was detected in all studied brain structures: amygdala, hippocampus, and hypothalamus. The highest concentration of DAG was noted in the hypothalamus (p 0.05), which may serve as an indirect confirmation of the data on the presence of ghrelin-containing neurons in the nuclei of the hypothalamus. After exposure to stress, a sharp decrease in the level of DAG was observed in all studied brain structures (812 times, p 0.01): amygdala, hippocampus, and hypothalamus. It has been established that the experience of the stress of the death of a partner is expressed by erosive inflammation of the gastric mucosa, the death of many mucous cells, and an increase in mucus production in viable epithelial cells. CONCLUSION: Psychoemotional stress completely suppresses the content of desacyl ghrelin of the brain in rats, which may be based on both a disturbance of the central mechanisms of limbic regulation and a violation of peripheral mechanisms, in particular, reactive changes in the gastric mucosa.

A Systematic Review and Meta-Analysis Finds Increased Blood Levels of All Forms of Ghrelin in Both Restricting and Binge-Eating/Purging Subtypes of Anorexia Nervosa

Anorexia nervosa (AN) is a severe psychiatric condition associated with high mortality and chronicity. The hunt for state, trait, subtyping, and prognostic biomarkers is ongoing and the orexigenic hormone ghrelin and its different forms, acyl ghrelin and desacyl ghrelin, have been proposed to be increased in AN, especially in the restrictive subtype. A systematic literature search was performed using established databases up to 30 November 2020. Forty-nine studies met inclusion criteria for cross-sectional and longitudinal meta-analyses on total ghrelin, acyl ghrelin, and desacyl ghrelin. All forms of ghrelin were increased in the acute stage of anorexia nervosa during fasting compared to healthy controls. Previous notions on differences in ghrelin levels between AN subtypes were not supported by current data. In addition, a significant decrease in total ghrelin was observed pre-treatment to follow-up. However, total ghrelin levels at follow-up were still marginally elevated compared to healthy controls, whereas for acyl ghrelin, no overall effect of treatment was observed. Due to heterogeneity in follow-up designs and only few data on long-term recovered patients, longitudinal results should be interpreted with caution. While the first steps towards a biomarker in acute AN have been completed, the value of ghrelin as a potential indicator of treatment success or recovery status or its use in subtype differentiation are yet to be established.

MON-603 GPR142 Expression Levels Were Correlated with Plasma Ghrelin Levels and Heights in Morbidly Obese Patients

Recently, aromatic amino acids, especially tryptophan were discovered to be the strongest ligands for GPR142, which was previously known as an orphan GPCR. GPR142 is expressed in the digestive tract and pancreas in mice and human. Previously we found that GPR142 is highly expressed in the ghrelin-producing cell line, MGN3-1 cells, and that tryptophan strongly stimulated ghrelin secretion in vitro. In this study, we measured the mRNA expression levels of GPR142 in the gastric samples of 6 morbid obese patients undergone laparoscopic sleeve gastrectomy and compared its level with their clinical parameters. GPR142 expression levels were negatively correlated with plasma desacyl ghrelin levels (p=0.011) and positively correlated with heights (p=0.08). The current results that GPR142 expression levels were correlated with plasma desacyl ghrelin levels may confirm the link between GPR142 signal and regulation of ghrelin secretion demonstrated in our in vitro study. Regarding to the correlation with heights, there are some reports that plasma ghrelin levels were inversely correlated with heights in children[1-3], although, as far as we know, there are no reports demonstrating the relationship between plasma ghrelin levels and heights in adults. Considering that ghrelin strongly stimulates growth hormone secretion, GPR142 signaling may have influence on height through regulating ghrelin-growth hormone axis. Conclusion GPR142 mRNA expression levels were negatively and positively correlated with plasma desacyl ghrelin levels and heights in morbid obese adults undergone bariatric surgery. Current results may help understanding the pathophysiological role of GPR142 in the regulation of ghrelin secretion and heights. References 1. MO Camurdan, et al. Endocrine Journal 2006, 53 (4), 479–484 2. HS Park, et al. Metabolism Clinical and Experimental 2005, 54, 925–929 3. Joy C. Bunt,et al. J Clin Endocrinol Metab 2003, 88(8): 3756-3761