Age, sex, and lactating status regulate ghrelin secretion and GOAT mRNA levels from isolated rat stomach

2010 ◽  
Vol 299 (3) ◽  
pp. E341-E350 ◽  
Author(s):  
O. Al-Massadi ◽  
A. B. Crujeiras ◽  
R. C. González ◽  
M. Pardo ◽  
C. Diéguez ◽  
...  

Ghrelin is a stomach derivate peptide involved in energy homeostasis regulation, and ghrelin O-acyltransferase (GOAT) is the enzyme responsible for ghrelin acylation. Puberty is a period characterized by profound changes in the metabolic requirements and notable variations of sexual hormone levels. On the other hand, the weaning process is a fundamental modification of the diet, which implicates several adaptations of the gastrointestinal tract physiology. Until now the direct secretion of ghrelin by the stomach in these conditions, without interferences from other organs, has never been studied. The main objective of this article was to investigate how the stomach modulates ghrelin production and secretion as well as GOAT expression on these periods of life. Gastric ghrelin secretion is regulated through postnatal life in an independent way of gastric expression and circulating levels of this hormone. The present work shows a strong regulation of gastric ghrelin secretion by estrogens. The weaning strongly regulates gastric ghrelin secretion. Animals subjected to delayed weaning present a lower body weight than the corresponding controls. For the first time, it is shown that a noticeable decrease in circulating levels of testosterone and estrogens is associated with delay of weaning. GOAT mRNA levels in the stomach are strongly regulated by age, breastfeeding, and testosterone. In conclusion, the stomach itself regulates ghrelin and GOAT production to adapt the organism to the metabolic requirements demanded through each stage of life.

2001 ◽  
Vol 86 (10) ◽  
pp. 4753-4758 ◽  
Author(s):  
Hiroyuki Ariyasu ◽  
Kazuhiko Takaya ◽  
Tetsuya Tagami ◽  
Yoshihiro Ogawa ◽  
Kiminori Hosoda ◽  
...  

Ghrelin, an endogenous ligand for the GH secretagogue receptor, was isolated from rat stomach and is involved in a novel system for regulating GH release. Although previous studies in rodents suggest that ghrelin is also involved in energy homeostasis and that ghrelin secretion is influenced by feeding, little is known about plasma ghrelin in humans. To address this issue, we studied plasma ghrelin-like immunoreactivity levels and elucidated the source of circulating ghrelin and the effects of feeding state on plasma ghrelin-like immunoreactivity levels in humans. The plasma ghrelin-like immunoreactivity concentration in normal humans measured by a specific RIA was 166.0 ± 10.1 fmol/ml. Northern blot analysis of various human tissues identified ghrelin mRNA found most abundantly in the stomach and plasma ghrelin-like immunoreactivity levels in totally gastrectomized patients were reduced to 35% of those in normal controls. Plasma ghrelin-like immunoreactivity levels were increased by 31% after 12-h fasting and reduced by 22% immediately after habitual feeding. In patients with anorexia nervosa, plasma ghrelin-like immunoreactivity levels were markedly elevated compared with those in normal controls (401.2 ± 58.4 vs. 192.8 ± 19.4 fmol/ml) and were negatively correlated with body mass indexes. We conclude that the stomach is a major source of circulating ghrelin and that plasma ghrelin-like immunoreactivity levels reflect acute and chronic feeding states in humans.


2002 ◽  
pp. 159-163 ◽  
Author(s):  
JE Caminos ◽  
LM Seoane ◽  
SA Tovar ◽  
FF Casanueva ◽  
C Dieguez

OBJECTIVE: To assess whether some of the alterations in energy homeostasis present in thyroid function disorders and GH deficiency could be mediated by ghrelin. DESIGN: To assess the influence of thyroid status on ghrelin, adult male Sprague-Dawley rats were treated with vehicle (euthyroid), amino-triazole (hypothyroid) or l-thyroxine (hyperthyroid). The influence of GH on ghrelin was assessed in wild-type (control) and GH-deficient (dwarf) Lewis rats. Evaluation of gastric ghrelin mRNA expression in the stomach was carried out by Northern blot. Circulating levels of ghrelin were measured by radioimmunoassay. RESULTS: Hypothyroidism resulted in an increase in gastric ghrelin mRNA levels (euthyroid: 100+/-3.2% vs hypothyroid: 127.3+/-6.5%; P<0.01), being decreased in hyperthyroid rats (70+/-5.4%; P<0.01). In keeping with these results, circulating plasma ghrelin levels were increased in hypothyroid (euthyroid: 124+/-11 pg/ml vs hypothyroid: 262+/-39 pg/ml; P<0.01) and decreased in hyperthyroid rats (75+/-6 pg/ml; P<0.01). Using an experimental model of GH deficiency, namely the dwarf rat, we found a decrease in gastric ghrelin mRNA levels (controls: 100+/-6% vs dwarf: 66+/-5.5%; P<0.01) and circulating plasma ghrelin levels (controls: 124+/-12 pg/ml vs dwarf: 81+/-7 pg/ml; P<0.01). CONCLUSION: This study provides the first evidence that ghrelin gene expression is influenced by thyroid hormones and GH status and provides further evidence that ghrelin may play an important role in the alteration of energy homeostasis and body weight present in these pathophysiological states.


2021 ◽  
Vol 22 (3) ◽  
pp. 1435
Author(s):  
Aimilia Papathanasiou ◽  
Fotios Spyropoulos ◽  
Zoe Michael ◽  
Kyoung Joung ◽  
Despina Briana ◽  
...  

Pulmonary hypertension (PH) is associated with meta-inflammation related to obesity but the role of adipose tissue in PH pathogenesis is unknown. We hypothesized that adipose tissue-derived metabolic regulators are altered in human and experimental PH. We measured circulating levels of fatty acid binding protein 4 (FABP-4), fibroblast growth factor -21 (FGF-21), adiponectin, and the mRNA levels of FABP-4, FGF-21, and peroxisome proliferator-activated receptor γ (PPARγ) in lung tissue of patients with idiopathic PH and healthy controls. We also evaluated lung and adipose tissue expression of these mediators in the three most commonly used experimental rodent models of pulmonary hypertension. Circulating levels of FABP-4, FGF-21, and adiponectin were significantly elevated in PH patients compared to controls and the mRNA levels of these regulators and PPARγ were also significantly increased in human PH lungs and in the lungs of rats with experimental PH compared to controls. These findings were coupled with increased levels of adipose tissue mRNA of genes related to glucose uptake, glycolysis, tricarboxylic acid cycle, and fatty acid oxidation in experimental PH. Our results support that metabolic alterations in human PH are recapitulated in rodent models of the disease and suggest that adipose tissue may contribute to PH pathogenesis.


2014 ◽  
Vol 8 (6) ◽  
pp. 388-393 ◽  
Author(s):  
Atif Afzal ◽  
Daniel Fung ◽  
Sean Galligan ◽  
Ellen M. Godwin ◽  
John G. Kral ◽  
...  

1989 ◽  
Vol 257 (3) ◽  
pp. H904-H911 ◽  
Author(s):  
S. Ramanadham ◽  
J. J. Mongold ◽  
R. W. Brownsey ◽  
G. H. Cros ◽  
J. H. McNeill

Recent reports have suggested that vanadium in the form of vanadyl (+IV) possesses insulin-like activity. Therefore, in the present study we examined the effects of administering oral vanadyl to diabetic animals. Wistar rats made diabetic with streptozotocin and age-matched controls were maintained for 10 wk in the absence and presence of vanadyl sulfate trihydrate in the drinking water. In the presence of vanadyl, decreases in rate of growth and circulating levels of insulin were the only significant alterations recorded in control animals. In contrast, diabetic animals treated with vanadyl, despite having lower body weights and insulin levels, had normal plasma concentrations of glucose, lipid, creatinine, and thyroid hormone. In addition, abnormalities in isolated working heart function and glycerol output from adipose tissue of diabetic animals were also corrected after vanadyl treatment. These results suggest that vanadium when used in the vanadyl form is effective in diminishing the diabetic state in the rat by substituting for and replacing insulin or possibly by enhancing the effects of endogenous insulin.


2018 ◽  
Vol 243 (5) ◽  
pp. 408-417 ◽  
Author(s):  
Yong-Sub Byun ◽  
Eun-Kyoung Kim ◽  
Kimi Araki ◽  
Ken-ichi Yamamura ◽  
Kihoon Lee ◽  
...  

FRY like transcription coactivator ( Fryl) gene located on chromosome 5 is a paralog of FRY microtubule binding protein ( Fry) in vertebrates. It encodes a protein with unknown functions. Fryl gene is conserved in various species ranging from eukaryotes to human. Although there are several reports on functions of Fry gene, functions of Fryl gene remain unclear. A mouse line containing null mutation in Fryl gene by gene trapping was produced in this study for the first time. The survival and growth of Fryl−/− mice were observed. Fryl gene expression levels in mouse tissues were determined and histopathologic analyses were conducted. Most Fryl−/− mice died soon after birth. Rare Fryl−/− survivors showed growth retardation with significantly lower body weight compared to their littermate controls. Although they could breed, more than half of Fryl−/− survivors died of hydronephrosis before age 1. No abnormal histopathologic lesion was apparent in full-term embryo or adult tissues except the kidney. Abnormal lining cell layer detachments from walls of collecting and convoluted tubules in kidneys were apparent in Fryl−/− neonates and full-term embryos. Fryl gene was expressed in renal tubular tissues including the glomeruli and convoluted and collecting tubules. This indicates that defects in tubular systems are associated with Fryl functions and death of Fryl−/− neonates. Fryl protein is required for normal development and functional maintenance of kidney in mice. This is the first report of in vivo Fryl gene functions. Impact statement FRY like transcription coactivator ( Fryl) gene is conserved in various species ranging from eukaryotes to human. It expresses a protein with unknown function. We generated a Fryl gene mutant mouse line and found that most homozygous mice died soon after their birth. Rare Fryl−/− survivors showed growth retardation with significantly lower body weight compared to their littermate controls. Although they could breed, more than half of Fryl−/− survivors died of hydronephrosis before age 1. Full-term mutant embryos showed abnormal collecting and convoluted tubules in kidneys where Fryl gene was expressed. Collectively, these results indicate that Fryl protein is required for normal development and functional maintenance of kidney in mice. To the best of our knowledge, this is the first report on in vivo Fryl gene functions.


2016 ◽  
Vol 310 (2) ◽  
pp. E103-E115 ◽  
Author(s):  
Lionel Carneiro ◽  
Sarah Geller ◽  
Xavier Fioramonti ◽  
Audrey Hébert ◽  
Cendrine Repond ◽  
...  

Monocarboxylates have been implicated in the control of energy homeostasis. Among them, the putative role of ketone bodies produced notably during high-fat diet (HFD) has not been thoroughly explored. In this study, we aimed to determine the impact of a specific rise in cerebral ketone bodies on food intake and energy homeostasis regulation. A carotid infusion of ketone bodies was performed on mice to stimulate sensitive brain areas for 6 or 12 h. At each time point, food intake and different markers of energy homeostasis were analyzed to reveal the consequences of cerebral increase in ketone body level detection. First, an increase in food intake appeared over a 12-h period of brain ketone body perfusion. This stimulated food intake was associated with an increased expression of the hypothalamic neuropeptides NPY and AgRP as well as phosphorylated AMPK and is due to ketone bodies sensed by the brain, as blood ketone body levels did not change at that time. In parallel, gluconeogenesis and insulin sensitivity were transiently altered. Indeed, a dysregulation of glucose production and insulin secretion was observed after 6 h of ketone body perfusion, which reversed to normal at 12 h of perfusion. Altogether, these results suggest that an increase in brain ketone body concentration leads to hyperphagia and a transient perturbation of peripheral metabolic homeostasis.


2021 ◽  
Author(s):  
Ana Luísa Teixeira ◽  
Ana Sofia Patrão ◽  
Francisca Dias ◽  
Carlos Silva ◽  
Isabel Vieira ◽  
...  

Aim: Renal cell carcinoma (RCC) is the most lethal urological cancer and up to 40% of patients submitted to surgery will relapse. Thus, the study aim was to analyze the associations of AGO2 SNPs with RCC patients’ prognosis, and evaluate their effect on AGO2 mRNA levels. Materials & methods: The AGO2 rs4961280, rs3928672 and rs11996715 polymorphisms and the relative quantification of AGO2 mRNA levels were analyzed by real-time PCR. Results: We observed that AGO2 rs4961280 AC + AA genotypes carriers presented a higher cancer progression risk (OR= 3.13, p < 0.001), a reduced progression-free survival (log rank test, p = 0.003) and an increased risk of an early relapse (HR= 2.26, p = 0.008). In fact, these patients also presented higher circulating levels of AGO2 mRNA (p = 0.043), with the high levels being associated with more aggressive tumors. Conclusion: The AGO2  rs4961280 AA/AC genotypes are unfavorable RCC prognostic biomarkers, with the AGO2 levels being a useful RCC aggressive phenotype biomarker.


Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Nicole K Littlejohn ◽  
Benjamin J Weidemann ◽  
Nicole A Pearson ◽  
Kathleen R Markan ◽  
Matthew J Potthoff ◽  
...  

The renin-angiotensin system (RAS) positively correlates with obesity, and contributes to energy homeostasis through opposing actions in the brain and adipose. We hypothesize that site- and receptor-specific modulation may represent a novel therapeutic target for obesity. Transgenic “sRA” mice exhibit brain-specific RAS hyperactivity through expression of human renin in neurons (synapsin promoter) and human angiotensinogen via its own promoter. Previously we documented that sRA mice exhibit a suppressed circulating RAS, and an elevated resting metabolic rate (RMR) that is sensitive to replacement of circulating angiotensin II or the AT 2 receptor (AT 2 R) agonist, CGP-42112a (CGP, 100 ng/kg/min, s.c.). sRA mice consume more food than littermate controls (con n=7, 12.98±0.65 vs sRA n=8, 15.41±0.70 g/d, P<0.05), but because of a major suppression of digestive efficiency (con 77.6±2.3 vs sRA 59.3±4.7 % consumed, P<0.05), sRA mice absorb a normal number of calories (con 10.04±0.50 vs sRA 9.07±0.76 kcal/d). Chronic CGP had no effect on total daily caloric absorption (con+CGP n=7, 9.83±0.95 vs sRA+CGP n=5, 9.32±0.80 kcal/d); however CGP appears to disproportionately increase weight gain in sRA mice (vehicle +0.33±0.49 vs CGP +1.54±0.47 g/8 wks, P=0.27) compared to control mice (vehicle +2.12±1.00 vs CGP +2.47±0.73 g/8 wks, P=0.73), consistent with a suppression of energy expenditure by CGP. Given the increased RMR and core temperature in sRA mice, we next examined the expression of uncoupling protein-1 (UCP1) content of thermogenic adipose tissues by Western blot (all n=3, vs perilipin). Interscapular brown adipose tissue UCP1 was unchanged in sRA mice (94±6%), and weakly suppressed by CGP treatment (84±4% of sRA). Inguinal adipose UCP1 was increased in sRA mice (198±13%), and this was suppressed by CGP treatment (72±9% of sRA). UCP1 mRNA levels paralleled protein in both fat types. Cultured adipocytes from 4 day old AT 2 -deficient mice exhibited increased UCP1 protein vs littermate controls (190%). Further, CGP (10 nM) reduced UCP1 in control adipocytes (by 30%). These data support a suppressive action of AT 2 R upon RMR most likely through UCP1. Inguinal adipose AT 2 R may therefore contribute to obesity through suppression of RMR.


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