Role of endogenous ghrelin in growth hormone secretion, appetite regulation and metabolism

Dimaraki, Eleni V.; Jaffe, Craig A.

doi:10.1007/s11154-006-9022-0

Cited by 69 publications

(44 citation statements)

References 156 publications

(189 reference statements)

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“…The role of endogenous AG in the physiology of GH secretion, while suspected, had not been convincingly demonstrated (10). Recently, using the same two-site sandwich assay that recognizes full-length AG, Nass et al (28) observed in eight young, lean male subjects a significant correlation between the amplitude of GH pulses and the concentrations of AG, supporting the hypothesis that endogenous ghrelin modulates GH secretion.…”

Section: Discussionmentioning

confidence: 99%

Acylated ghrelin concentrations are markedly decreased during pregnancy in mothers with and without gestational diabetes: relationship with cholinesterase

Tham

Jian-hua²,

Innis³

et al. 2009

American Journal of Physiology-Endocrinology and Metabolism

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Tham E, Liu J, Innis S, Thompson D, Gaylinn BD, Bogarin R, Haim A, Thorner MO, Chanoine JP. Acylated ghrelin concentrations are markedly decreased during pregnancy in mothers with and without gestational diabetes: relationship with cholinesterase. Am J Physiol Endocrinol Metab 296: E1093-E1100, 2009. First published February 24, 2009 doi:10.1152 doi:10. /ajpendo.90866.2008 ghrelin stimulates food intake and growth hormone secretion and is deacylated into desacyl ghrelin by butyrylcholinesterase. Acylated and desacyl ghrelin both promote adipogenesis. Ghrelin concentrations decrease with hyperglycemia and hyperinsulinism. We hypothesized that 1) acylated ghrelin increases during pregnancy, contributing positively to energy balance, but is lower in women with gestational diabetes and 2) butyrylcholinesterase activity is inversely correlated with acylated ghrelin concentrations. In a first group of subjects, using two-site sandwich ghrelin assays that specifically detect full-length forms, we investigated women with and without gestational diabetes (n ϭ 14/group) during pregnancy and after delivery. We examined whether changes in ghrelin during a test meal were correlated with changes in pituitary growth hormone [assessed through calculation of the area under the curve (AUC) during the test meal]. In postpartum subjects, the percent of total ghrelin that is acylated was four to five times higher than previously observed using single antibody assays. During pregnancy, acylated ghrelin concentrations (mean Ϯ SE) were lower compared with the postpartum period throughout the meal (AUC 1.2 Ϯ 0.2 vs. 10.2 Ϯ 1.9 ng ⅐ ml Ϫ1 ⅐ 90 min Ϫ1 , P Ͻ 0.001). In the postpartum, acylated ghrelin and growth hormone were positively correlated (r ϭ 0.50, P ϭ 0.007). Desacyl (but not acylated) ghrelin was increased in subjects with gestational diabetes during and after pregnancy (AUC 15.4 Ϯ 1.9 vs. 8.6 Ϯ 1.2 ng ⅐ ml Ϫ1 ⅐ 90 min Ϫ1 , P ϭ 0.005). In a second group of subjects (n ϭ 13), acylated ghrelin was similarly suppressed during pregnancy. Circulating octanoate concentrations (3.1 Ϯ 0.5 vs. 4.5 Ϯ 0.6 g/ml, P ϭ 0.029) and cholinesterase activity (705 Ϯ 33 vs. 1,013 Ϯ 56 U/ml, P Ͻ 0.001) were lower during pregnancy compared with the postpartum period. In conclusion, acylated ghrelin markedly decreases during pregnancy, likely because of a decrease in the acylation process. Desacyl ghrelin increases in gestational diabetes, possibly reflecting resistance to the inhibitory effect of insulin on ghrelin secretion. In vitro studies suggest that, in humans, circulating ghrelin is deacylated rapidly, at least in part by the enzyme cholinesterase (also known as pseudocholinesterase or butyrylcholinesterase, EC 3.1.1.8) (9).Both AG and DG could potentially play a physiological role in energy balance. Exogenous administration of AG, but not DG, stimulates GH secretion (35) and has orexigenic effects (41) in humans. AG injection also causes hyperglycemia and a decrease in circulating insulin (2). In addition, in rodents, administration of both AG...

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Section: Discussionmentioning

confidence: 99%

Acylated ghrelin concentrations are markedly decreased during pregnancy in mothers with and without gestational diabetes: relationship with cholinesterase

Tham

Jian-hua²,

Innis³

et al. 2009

American Journal of Physiology-Endocrinology and Metabolism

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“…It was discovered in 1999 by Kojima et al [1]. The purification of ghrelin was performed by screening several tissues and high amount of this hormone was found in stomach extracts [2]. The discovery of ghrelin was rooted in the search for an endogenous ligand for the growth hormone secretagogue receptor (GHS -R) [1].…”

Section: Introductionmentioning

confidence: 99%

The activity of gastric ghrelin positive cells in obese patients treated surgically.

Dadan

Hady²,

Zbucki³

et al. 2009

Folia Histochem Cytobiol.

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Abstract:Ghrelin is a 28 amino acid peptide hormone regulating food intake and stimulating releasement of growth hormone. It is produced in a distinct endocrine call known as X/A -like cells. The most abundant source of this very important factor in energy homeostasis is gastric fundus. Regulatory mechanisms of ghrelin synthesis and secretion in physiological and pathological states are not discovered completely. The aim of our study was evaluation of the activity of gastric X/A-like cells in obese patients before and after the most popular surgical bariatric procedures -Roux -Y Gastric Bypass (RYGB) and Laparoscopic Adjustable Gastric Banding (LAGB). Obese patients in number 18 took part in the study. LAGB was performed in 7 patients and RYGB in 11 patients. Peripheral blood was taken from each patient before operation and first day, seventh day, one month and three months after surgery. Ghrelin level was determined by RIA technique. The specimen of stomach was taken from circular stapler after gastrojejunostomy during RYGB and immunohistochemical study of gastric mucosa, using the EnVision method and specific monoclonal antybodies against ghrelin was performed. The intensity of ghrelin-immunoreactivity in X/A-like cells was analyzed using Olympus Cell D image analysis system. Efficiency of bariatric procedures was estimated by EWL-excess weight loss. We observed very strong immunohistochemical reactions of gastric X/A-like cells, accompanied by lower ghrelin plasma concentration, in comparison to the control group. LAGB procedure induced increase of ghrelin plasma level while RYGB procedure induced decrease of this hormone. The main finding of the present study is the hypoactivity of gastric X/A-like cells in obese patients in comparison to the control group.

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“…In the brain, neurons that produce ghrelin have been identified in the pituitary, hypothalamus ARC, and group of neurons in the dorsal, ventral, paraventricular and hypothalamic arcuatus nucleus [4]. Ghrelin binds to growth hormone secretory receptor (GHS-R) [4], [5] and has a role in the regulation as opposed to satiation peptides. Ghrelin stimulates the activity of neurons expressing NPY, AgRP and orexin; on the other hand, it suppressed the effect of POMC neurons and CRH-producing neurons [4].…”

Section: Discussionmentioning

confidence: 99%

The Effect of Cadmium Absorption on Ghrelin and Malondialdehyde Levels in White Rats (Rattusnorvegicus)

Triawanti¹,

Sanyoto²,

Mashuri³

et al. 2014

IJBBB

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Abstract-Cadmium is expected to affect the absorption of other nutrients and appetite through the competition with the nutrients, causing damages to cell membranes through lipid peroxidation reactions. Damaged intestinal cells may disrupt the secretion of one of digestive hormones, ghrelin, theorexigenic hormone. The purpose of this study was to analyze the effect of cadmium exposure on the levels of ghrelin and malondialdehyde (MDA) in rats (Rattusnorvegicus). The study used post-test-only control group design, with 2 groups of white rats: control group (P0) was given placebo and treatment group (P1) was exposed to cadmium. Parameters measured were the levels of MDA and ghrelin. The results showed that there was no difference in body weights (p=0.057) and ghrelin concentrations (p=0.910) between the white rats in the control group and the treatment group. There were significant differences in the levels of MDA. The treatment group had a higher MDA level compared with control (p=0.001). It was concluded that the cadmium exposure for 4 group did not affect the secretion of ghrelin hormone and body weights of white rats, but might cause lipid peroxidation in white rats, as evidenced by the increased MDA level.

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Role of endogenous ghrelin in growth hormone secretion, appetite regulation and metabolism

Cited by 69 publications

References 156 publications

Acylated ghrelin concentrations are markedly decreased during pregnancy in mothers with and without gestational diabetes: relationship with cholinesterase

Acylated ghrelin concentrations are markedly decreased during pregnancy in mothers with and without gestational diabetes: relationship with cholinesterase

The activity of gastric ghrelin positive cells in obese patients treated surgically.

The Effect of Cadmium Absorption on Ghrelin and Malondialdehyde Levels in White Rats (Rattusnorvegicus)

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