Kidney produces a novel acylated peptide, ghrelin

Mori, Kiyoshi; Yoshimoto, Akihiro; Takaya, Kazuhiko; Hosoda, Kiminori; Ariyasu, Hiroyuki; Yahata, Kensei; Mukoyama, Masashi; Sugawara, Akira; Hosoda, Hiroshi; Kojima, Masayasu; Kangawa, Kenji; Nakao, Kazuwa

doi:10.1016/s0014-5793(00)02308-5

Cited by 294 publications

(185 citation statements)

References 22 publications

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“…Interestingly, this finding was restricted to cases from the embryonic period because two cases from the fetal period having ciliated or stratified epithelium apparently lacked ghrelin immunoreactivity. With regard to the other tissues, we have been unable to confirm the data of Mori et al (2000) on ghrelin expression by the kidney. The fetal kidneys (as well as two cases of adult kidney analyzed in parallel; data not shown) were completely unreactive by IHC.…”

Section: Discussioncontrasting

confidence: 83%

“…It has complex functions related to GH release, gastrointestinal motility, and food intake control (Kojima et al 1999;Dieguez and Casanueva 2000;Wren et al 2000;Arvat et al 2001;Broglio et al 2001), which are mediated by specific receptors present either in the brain and pituitary or in peripheral organs in both normal and neoplastic tissues (Muccioli et al 1998;Kojima et al 1999;Cassoni et al 2000Cassoni et al ,2001Papotti et al 2000b). Ghrelin has subsequently been localized in the pituitary gland, arcuate nucleus of the hypothalamus, kidney, and placenta (Kojima et al 1999;Date et al 2000;Mori et al 2000;Gualillo et al 2001). Some tumors were also found to produce ghrelin, i.e., pituitary adenomas, gastrointestinal carcinoids, and endocrine tumors of the pancreas (Kim et al 2001;Korbonits et al 2001;Papotti et al 2001;Volante et al 2002).…”

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confidence: 99%

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Ghrelin Expression in Fetal, Infant, and Adult Human Lung

Volante

Fulcheri²,

Allìa

et al. 2002

J Histochem Cytochem.

131

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S U M M A R YGhrelin is a recently identified hormone with potent growth hormone (GH)-releasing activity. It is produced by rat and human gastric endocrine cells and by the pituitary, hypothalamus, placenta, and by gastroenteropancreatic tumors. No evidence of ghrelin production by foregut-derived organs other than stomach has been provided to date. The aim of the present study was to investigate ghrelin expression by human fetal (20 cases), infant (13 cases), and adult (seven cases) lungs by immunohistochemistry, in situ hybridization, and RT-PCR. Expression of the GH secretagogue receptor, the endogenous receptor for ghrelin, was also investigated by RT-PCR. Ghrelin protein was found in the endocrine cells of the fetal lung in decreasing amounts from embryonic to late fetal periods. Its expression was maintained in newborns and children under 2 years but was virtually absent in older individuals. Scattered positive cells were also found in the trachea and the esophagus. Ghrelin mRNA was detected in adult lung by the more sensitive RT-PCR technique. GHS receptor mRNA was detected in nine cases of infant and adult lungs, possibly indicating the existence of local autocrine circuits. We conclude that the fetal lung is an additional source of circulating ghrelin, whose functions at the respiratory tract level remain to be clarified. (J Histochem

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Section: Discussioncontrasting

confidence: 83%

mentioning

confidence: 99%

Ghrelin Expression in Fetal, Infant, and Adult Human Lung

Volante

Fulcheri²,

Allìa

et al. 2002

J Histochem Cytochem.

131

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“…Growing evidence indicates that, in addition to their central actions in the control of GH secretion and food intake, peripheral effects of GHS-R ligands are likely to take place. This is suggested by the wide range of endocrine and non-endocrine tissues that possess GHS-binding sites and express the GHS-R gene in humans (12,41), and the novel expression of ghrelin in non-central tissues, such as placenta, kidney and pancreas (38,48,49). In good agreement, we have recently gathered data on the expression and functional role of ghrelin in rat testis (28).…”

Section: Discussionsupporting

confidence: 68%

Expression and homologous regulation of GH secretagogue receptor mRNA in rat adrenal gland

Barreiro

Pinilla²,

Aguilar³

et al. 2002

European Journal of Endocrinology

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Objective: GH secretagogues (GHSs) elicit a variety of biological effects in several endocrine and nonendocrine target tissues, including activation of the hypothalamic -pituitary-adrenal axis. The latter is mainly carried out through a central hypothalamic action; yet the possibility of additional effects directly at the adrenal level cannot be ruled out. The aims of this study were to evaluate the expression and homologous regulation of the GHS-receptor (GHS-R) gene in rat adrenal and to assess the effects of synthetic (GH releasing peptide-6 -GHRP-6) and natural (ghrelin) ligands of GHS-R upon basal and ACTH-stimulated corticosterone secretion in vitro. Design and Methods: Analysis of adrenal expression of target mRNAs (GHS-R, GHS-R1a, ghrelin, and several steroidogenic factors) was conducted by means of primer-specific, semi-quantitative RT-PCR. Evaluation of corticosterone secretion by incubated adrenal tissue was carried out by specific RIA. Results: RT-PCR analysis demonstrated expression of the GHS-R gene, but not of the gene encoding the cognate ligand ghrelin, in rat adrenal. Moreover, expression of the mRNA coding for the type 1a GHS-R (GHS-R1a), i.e. the biologically active receptor form, was demonstrated. The adrenal expression of the GHS-R message appeared under the regulation of homologous signals in vitro, as short-term incubation of adrenal samples in serum-free medium induced a significant increase in GHS-R mRNA levels that was inhibited by exposure to different doses of GHRP-6 (10 29 -10 25 mol/l) or ghrelin (10 27 mol/l). Notably, an opposite pattern of homologous regulation of GHS-R gene expression was observed at the pituitary. Finally, short-term stimulation with increasing concentrations of GHRP-6 (10 29 -10 25 mol/l) or ghrelin (10 27 mol/l) failed to alter basal and ACTHstimulated corticosterone secretion in vitro, neither did it modify ACTH-stimulated mRNA expression levels of several upstream elements in the steroidogenic route: the steroidogenic acute regulatory (StAR) protein, and the enzymes P450 cholesterol side-chain cleavage (P450scc) and 3b-hydroxysteroid dehydrogenase (3b-HSD). Conclusions: Our study provides novel evidence for the expression and homologous regulation of the GHS-R gene in rat adrenal. However, our results cast doubts on the possibility of direct adrenal actions of ligands of the GHS-R in the regulation of corticosterone secretion in the rat.

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“…This unchanged plasma ghrelin concentration may be the result of diminished inhibitory effect of SST or compensatory increased ghrelin release from other tissues. In fact, plasma ghrelin levels in the gastrectomized patients still remain about one-third of those in normal subjects, suggesting that tissues other than stomach, such as duodenum, jejunum, kidney and lung, contribute to a certain amount of circulating ghrelin (32,34). Plasma ghrelin concentration may not directly reflect ghrelin release from the oxyntic mucosa of the stomach.…”

Section: Discussionmentioning

confidence: 96%

Helicobacter pylori has no effect on plasma ghrelin levels

Gökçel

Gümürdülü

Kayaselçuk

et al. 2003

European Journal of Endocrinology

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Objective: Helicobacter pylori is the major etiologic agent for chronic active gastritis, and it also plays a crucial role in gastric and duodenal ulcer disease, as well as in gastric carcinoma. H. pylori infection has been shown to decrease plasma somatostatin (SST) and increase plasma gastrin concentrations. Ghrelin is a recently discovered peptide produced mostly in the stomach of rodents and humans and is secreted into the bloodstream. There is no data in the literature about the relationship between H. pylori and ghrelin. Design: Thirty-nine age-and BMI-matched H. pylori infection positive and negative women, from whom biopsy specimens were taken during gastric endoscopy, were included in the study. Methods: Total ghrelin was measured by enzyme immunoassay (EIA) in Medistek. All samples were measured in duplicate and averaged; results differing by more than 20% were re-assayed. Two biopsy specimens from antrum, corpus and fundus were obtained. Results: Fifteen of the subjects were H. pylori negative and 24 were H. pylori positive. Age, BMI, lipid profile and insulin sensitivity indices of the groups were similar. Plasma ghrelin levels ð375:92^7:10 vs 370:00^4:14 pmol=l; P . 0:05Þ of H. pylori negative and positive groups did not differ significantly. Conclusion: H. pylori has no effect on plasma ghrelin concentration.

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Kidney produces a novel acylated peptide, ghrelin

Cited by 294 publications

References 22 publications

Ghrelin Expression in Fetal, Infant, and Adult Human Lung

Ghrelin Expression in Fetal, Infant, and Adult Human Lung

Expression and homologous regulation of GH secretagogue receptor mRNA in rat adrenal gland

Helicobacter pylori has no effect on plasma ghrelin levels

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