it is known that urocortin 1 (UCN) acts on both corticotropinreleasing factor receptors (CRF 1 and CRF2), the mechanisms underlying UCN-induced anorexia remain unclear. In contrast, ghrelin, the endogenous ligand for the growth hormone secretagogue receptor, stimulates food intake. In the present study, we examined the effects of CRF 1 and CRF2 receptor antagonists (CRF1a and CRF2a) on ghrelin secretion and synthesis, c-fos mRNA expression in the caudal brain stem, and food intake following intracerebroventricular administration of UCN. Eight-week-old, male Sprague-Dawley rats were used after 24-h food deprivation. Acylated and des-acylated ghrelin levels were measured by enzyme-linked immunosorbent assay. The mRNA expressions of preproghrelin and c-fos were measured by real-time RT-PCR. The present study provided the following important insights into the mechanisms underlying the anorectic effects of UCN: 1) UCN increased acylated and des-acylated ghrelin levels in the gastric body and decreased their levels in the plasma; 2) UCN decreased preproghrelin mRNA levels in the gastric body; 3) UCN-induced reduction of plasma ghrelin and food intake were restored by CRF 2a but not CRF1a; 4) UCN-induced increase of c-fos mRNA levels in the caudal brain stem containing the nucleus of the solitary tract (NTS) was inhibited by CRF 2a; and 5) UCN-induced reduction of food intake was restored by exogenous ghrelin and rikkunshito, an endogenous ghrelin secretion regulator. Thus, UCN increases neuronal activation in the caudal brain stem containing NTS via CRF 2 receptors, which may be related to UCN-induced inhibition of both ghrelin secretion and food intake.corticotropin-releasing factor receptors; dorsal vagal complex; rikkunshito; digestive system hormone; anorexia STRESSFUL LIFE EVENTS have been associated with the onset or symptom exacerbation of several functional gastrointestinal disorders including functional dyspepsia and irritable bowel syndrome (24). Corticotropin-releasing factor (CRF) is a key mediator in the central nervous system and is secreted as an adaptive response to stress. In rodents, central CRF administration induces stress-like behaviors, including increased depression, decreased rearing activity, and suppression of food intake (5, 50). Urocortin 1 (UCN), a member of the mammalian CRF family, bears 45% sequence identity to CRF and acts as an endogenous ligand for CRF receptors (49). Although CRF and UCN mediate their actions through the activation of CRF 1 and CRF 2 receptors, CRF and UCN display different binding affinities for these receptors. CRF preferentially binds to CRF 1 receptors, whereas UCN shows high affinity for both receptors; we therefore believe that UCN is useful for examining the actions of both CRF 1 and CRF 2 receptors. Central UCN administration suppresses feeding in rats and mice, and the suppression was shown to be at least partly CRF 2 mediated in studies that used selective antagonists (7) or antisense oligonucleotides (38). In addition, the initial effect of food intake in...
The aims of this study were to investigate the expression of pentraxin-3 in inflamed gastrointestinal tissue in patients with inflammatory bowel diseases and to elucidate the usefulness of plasma pentraxin-3 level as an inflammation marker in patients with inflammatory bowel diseases. Pentraxin-3 immunoreactivity was found in infiltrating neutrophils and vessels in the inflamed gut. Plasma pentraxin-3 concentration in patients with active inflammatory bowel diseases was significantly higher than that of normal subjects and patients with inactive inflammatory bowel diseases. Significant positive correlations of clinical disease activity with plasma pentraxin-3 concentration and serum CRP concentration were found in patients with inflammatory bowel diseases. Pentraxin-3 is directly produced from the inflamed gut in inflammatory bowel diseases. In conclusion, plasma pentraxin-3 concentration is a useful marker for understanding the disease activity in patients with inflammatory bowel diseases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.