OBJECTIVETo explore the effect of electroacupuncture (EA) on the expression of Ghrelin and mRNA expression of its receptor in functional dyspepsia (FD) rats.

METHODSTotally 80 rats were divided into the normal group, the model group, the drug therapy group, and the EA group according to random digit table, 20 in each group. FD model was duplicated by clipping tail modeling. Drug containing cisapride [2 mL/100 g, 0.09 g/(kg x d)] was administered to rats in the drug therapy group from the 3rd day after successful modeling, once per day. EA at Zusanli (ST36) (0.3-0.5 cun) and Taichong (LR3) (0.1-0.2 cun) was performed in the EA group. The twirling of needle was performed to the subsidence of needle, and then the needle was connected to HANS-200A Acupoint Nerve Stimulating Device using disperse-dense wave at 2 Hz, 2 mA, 30 min each time, once per day. Six days consisted of one therapeutic course, two courses in total with an interval of one day. The intestinal propulsive rate of ink was observed. Ghrelin protein expression in gastric tissue was detected by Western blot. mRNA expression of growth hormone secretagogue receptor (GHS-R) in stomach, hypothalamus, and hippocampus was detected using Real-time PCR respectively.

RESULTSCompared with the normal group, the intestinal propulsive rate of ink, Ghrelin protein expression in gastric tissue, mRNA expression of GHS-R in stomach, hypothalamus, and hippocampus decreased in the model group (P < 0.05, P < 0.01). Compared with the model group, the intestinal propulsive rate of ink, Ghrelin protein expression in gastric tissue, mRNA expression of GHS-R in stomach, hypothalamus, and hippocampus increased in the EA group (P < 0.01); mRNA expression of GHS-R in stomach, hypothalamus, and hippocampus increased in the drug therapy group (P < 0.01). Compared with the drug therapy group, Ghrelin protein expression in gastric tissue, mRNA expression of GHS-R in hypothalamus increased in the EA group (P < 0.05, P < 0.01).

CONCLUSIONEA could regulate Ghrelin content and GHS-R mRNA expression of FD rat hypothalamus, hippocampus, and gastric tissue, and promote the intestinal propulsive rate of ink.

Acupuncture Points ; Animals ; Dyspepsia ; metabolism ; therapy ; Electroacupuncture ; Ghrelin ; metabolism ; Hippocampus ; metabolism ; Hypothalamus ; metabolism ; RNA, Messenger ; metabolism ; Random Allocation ; Rats ; Receptors, Ghrelin ; metabolism ; Stomach ; metabolism

OBJECTIVETo investigate the expression of ghrelin and its receptor, growth hormone secretagogue receptor (GHS-R), in the hypothalamus and gastrointestinal tract in rats with chronic renal failure (CRF) and explore their relationship with the disorder of gastrointestinal tract motility.

METHODSSD rats were randomly divided into sham-operated group (n=8) and CRF group (n=16), and in the latter group, the rats were subjected to 5/6 nephrectomy to induce CRF. Real-time PCR and immunohistochemical staining were used to detect the distribution of mRNA and protein of ghrelin and GHS-R in the gastric fundus, duodenum, and hypothalamus.

RESULTSThe rats in the CRF group showed a significantly higher expression of ghrelin mRNA and protein in the gastric fundus but a lower expression in the hypothalamus than those in the sham-operated group (P<0.01), but the expression in the duodenum was similar between the two groups (P>0.05). The expression of GHS-R mRNA and protein in the gastric fundus was significantly higher in the CRF group than in the sham-operated group (P<0.01), while in the hypothalamus and duodenum, the expression was significantly lower in the CRF group (P<0.01).

CONCLUSIONThe different distribution patterns of ghrelin and GHS-R in the tissues may be an important pathological basis of gastrointestinal motility disorder in CRF.

Animals ; Gastrointestinal Tract ; metabolism ; Ghrelin ; genetics ; metabolism ; Hypothalamus ; metabolism ; Kidney Failure, Chronic ; metabolism ; Male ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Ghrelin ; genetics ; metabolism

The cDNA of cattle Ghrelin gene was amplified from abomasum fundic gland mRNA of Qinchuan Cattle by RT-PCR. PCR product was cloned into the T vector pGM-T to construct pGh-T1 for sequencing. Then the cDNA was subcloned into the prokaryotic expressing plasmid vector pET32a (+) and transformed into host Escherichia coli strain BL21 (DE3) for expression. The expression of pGh-32 mature Ghrelin protein was induced by IPTG and was identified by SDS-PAGE. The expression product was observed with soluble protein and inclusion body. Western blotting showed that the recombinant protein was recognized by his-antibody specifically. The protein was purified by Ni-NTA column and was used to inject rabbits to obtain polyclona antibody. ELISA result showed that the antibody titer was 1:12 800. The immunohistochemistry test between the hypothalamus arcuate nucleus and the antibody showed that fusion protein had biological activity. This will provide a basis for further study on the biological function of Ghrelin protein to growth and development and fat deposition of cattle.
Animals ; Cattle ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Ghrelin ; genetics ; metabolism ; Recombinant Fusion Proteins ; genetics ; metabolism

OBJECTIVETo investigate the effect of the expression of ghrelin receptors on the postoperative small intestine dysmotility in rat models.

METHODSThe effect of different concentrations of ghrelin (0, 0.01, 0.1, 0.5, 1.0 μmol/L) on the contraction of smooth muscle strips of rat small intestine in the presence or absence of carbachol was observed in vitro. End-to-side anastomosis was performed in the study group and sham controls were used. The expression of ghrelin receptors(GHS-R1a) in small intestine muscle layers was detected by immunohistochemistry and Western blot.

RESULTSIn vitro, ghrelin enhanced the contraction of smooth muscle strips in the presence of carbachol, and the differences in contraction induced by different concentrations of ghrelin(0.1, 0.5, 1.0 μmol/L) were statistically significant [(223±18)%, (245±22)%, (264±25)%, P<0.01]. Immunohistochemistry study showed that GHS-R1a mainly located in the muscular layer of the bowel wall. The expression of GHS-R1a in the circular and longitudinal muscle was significantly weaker than that in the control group. The expression of ghrelin receptors after surgery was down-regulated in the study group, which was lower than that in the control group(0.51±0.02 vs. 0.71±0.01, P<0.01).

CONCLUSIONDown regulation of ghrelin receptors in small intestine muscle layers may contribute to the occurrence of small intestine dysmotility after intestinal surgery.

Animals ; Down-Regulation ; Gastrointestinal Motility ; drug effects ; physiology ; Ghrelin ; pharmacology ; Intestine, Small ; drug effects ; metabolism ; physiology ; surgery ; Male ; Postoperative Period ; Rats ; Rats, Sprague-Dawley ; Receptors, Ghrelin ; metabolism

OBJECTIVETo explore the expression of Ghrelin and high mobility group protein B1 (HMGB1) in the serum and the intestinal tissue of sepsis model rats, and to evaluate the effect of electro-acupuncture (EA) at Zusanli (ST36) on the expression of HMGB1 and Ghrelin.

METHODSForty-eight male Wistar rats were randomly divided into four groups, i.e., the sham-operation (sham), the cecal ligation and puncture group (CLP), the CLP + EA at Zusanli (ST36) group (EA), and the CLP + Ghrelin receptor blocking agent + EA group (GHSRA), 12 in each group. A sepsis rat model was prepared by CLP. The incision of the abdominal wall was immediately sutured along the ventral midline for rats in the Sham group. In the EA group EA at Zusanli (ST36) was performed 20 min after CLP surgery with the constant voltage (2 - 100 Hz, 2 mA) for 30 min. In the GHSRA group, Ghrelin receptor blocking agent, [D-Arg1, D-Phe5, D-Trp79, Leu11]-substance P (700 nmol/kg), was administered through intravenous injection immediately after CLP, and 20 min later, EA at Zusanli (ST36) was performed in the same way as for rats in the EA group. Blood samples were withdrawn 12 h after CLP. The serum levels of Ghrelin and HMGB1 were detected using ELISA. Ghrelin expressions and the number of Ghrelin immunopositive cell in the jejunum were determined by immunohistochemistry. HMGB1 contents of the jejunum tissue were detected by Western blotting.

RESULTSCompared with the Sham group, the number of serum immunopositive cells and the expression of HMGB1 in the jejunum tissue significantly increased and levels of Ghrelin and the expression rate of immunopositive cells significantly decreased in the CLP group (P < 0.05). Compared with the CLP group, the number of serum immunopositive cells and the expression of HMGB1 in the jejunum tissue significantly decreased, but levels of Ghrelin and the expression rate of immunopositive cells significantly increased in the EA group (P < 0.05). Compared with the EA group, the number of serum immunopositive cells and the expression of HMGB1 in the jejunum tissue significantly increased in the GHSRA group (P < 0.05), but there was no statistical difference in levels of Ghrelin between the two groups (P > 0.05). The serum level of HMGB1 was negatively correlated with Ghrelin in the Sham group, the CLP group, and the EA group (r = -0. 528, P < 0.01).

CONCLUSIONSEA at Zusanli (ST36) could inhibit the expression of HMGB1 in the jejunum of septic rats, and promote the expression of Ghrelin. The expression of HMGB1 was inhibited by Ghrelin receptor blocking agent, which suggested that the anti-inflammation of EA at Zusanli (ST36) might be associated with Ghrelin.

Animals ; Disease Models, Animal ; Electroacupuncture ; Ghrelin ; metabolism ; HMGB1 Protein ; metabolism ; Jejunum ; metabolism ; Male ; Rats ; Rats, Wistar ; Sepsis ; metabolism

Ghrelin, a novel gastrointestinal peptide with 28 amino acids, is secreted from the A-like cells of the gastric fundus. This peptide hormone does not only promote the release of growth hormone, but also stimulates food intake, gastric motility and cardiac output. Increased plasma ghrelin level has been reported in patients with upper gastrointestinal (GI) disease or in their disease animal model, suggesting its important role in the pathogenesis of upper GI disease.
Appetite/*physiology ; Cysteamine/metabolism ; Dyspepsia/etiology ; *Eating ; Gastrointestinal Diseases/*etiology ; Ghrelin/*physiology ; Humans ; Peptic Ulcer/etiology

Significant advancements have been made in the past century regarding the neuronal control of feeding behavior and energy expenditure. The effects and mechanisms of action of various peripheral metabolic signals on the brain have become clearer. Molecular and genetic tools for visualizing and manipulating individual components of brain homeostatic systems in combination with neuroanatomical, electrophysiological, behavioral, and pharmacological techniques have begun to elucidate the molecular and neuronal mechanisms of complex feeding behavior and energy expenditure. This review article highlights some of these advancements that have led to the current understanding of the brain's involvement in the acute and chronic regulation of energy homeostasis.
Brain ; Energy Metabolism ; Feeding Behavior ; Ghrelin ; Glucose ; Homeostasis ; Hunger ; Hypothalamus ; Leptin ; Neurons

The brain-gut peptide ghrelin, a endogenous ligand for the growth hormone secretagogue hormone receptor, is mainly produced by gastric cells in the periphery, regulating energy metabolism via stimulating the appetite. Inside the brain, ghrelin is mainly expressed in the pituitary and in the hypothalamic arcuate nucleus, regulating the synthesis and secretion of neuropeptides that are correlated with feeding behavior, reproduction, and stress responses. Recently, more and more researches focused on the regulating roles of ghrelin on learning and memory, and mood regulation have indicated that ghrelin may inhibit neuronal apoptosis, improve cognitive function, and regulate the activities of neuroendocrine systems such as the hypothalamo-pituitary-adrenal axis and the hypothalamo-pituitary-gonadal axis thus get involved in the pathogenesis of neuropsychiatric diseases. The aim of this review is to summarize the main findings in this field, with the purpose of promoting further studies on the role of ghrelin in the brain.
Apoptosis ; Brain ; metabolism ; pathology ; physiology ; Ghrelin ; metabolism ; physiology ; Humans ; Learning ; Memory ; Neurons ; pathology ; Parkinson Disease ; metabolism ; pathology ; physiopathology

OBJECTIVE: To investigate whether meranzin hydrate (MH) can alleviate depression-like behavior and hypomotility similar to Chaihu Shugan Powder (CSP), and further explore the potential common mechanisms. METHODS: Totally 120 Spraque-Dawley rats were randomly divided into 5-8 groups including sham, vehicle, fluoxetine (20 mg/kg), mosapride (10 mg/kg), CSP (30 g/kg), MH (9.18 mg/kg), [D-Lys3]-GHRP-6 (Dlys, 0.5 mg/kg), and MH+Dlys groups by a random number table, 8 rats in each group. And 32 mice were randomly divided into wild-type, MH (18 mg/kg), growth hormone secretagogue receptor-knockout (GHSR-KO), and GHSR+MH groups, 8 mice in each group. The forced swimming test (FST), open field test (OFT), tail suspension test (TST), gastric emptying (GE) test, and intestinal transit (IT) test were used to assess antidepressant and prokinetic (AP) effects after drug single administration for 30 min with absorbable identification in rats and mice, respectively. The protein expression levels of brain-derived neurotrophic factor (BDNF) and phosphorylated mammalian target of rapamycin (p-mTOR) in the hippocampus of rats were evaluated by Western blot. The differences in functional brain changes were determined via 7.0 T functional magnetic resonance imaging-blood oxygen level-dependent (fMRI-BOLD). RESULTS: MH treatment improved depression-like behavior (FST, OFT) and hypomotility (GE, IT) in the acute forced swimming (FS) rats (all P<0.05), and the effects are similar to the parent formula CSP. The ghrelin antagonist [D-Lys3]-GHRP-6 inhibited the effect of MH on FST and GE (P<0.05). Similarly, MH treatment also alleviated depression-like behavior (FST, TST) in the wild-type mice, however, no effects were found in the GHSR KO mice. Additionally, administration of MH significantly stimulated BDNF and p-mTOR protein expressions in the hippocampus (both P<0.01), which were also prevented by [D-Lys3]-GHRP-6 (P<0.01). Besides, 3 main BOLD foci following acute FS rats implicated activity in hippocampus-thalamus-basal ganglia (HTB) circuits. The [D-Lys3]-GHRP-6 synchronously inhibited BOLD HTB foci. As expected, prokinetic mosapride only had effects on the thalamus and basal ganglia, but not on the hippocampus. Within the HTB, the hippocampus is implicated in depression and FD. CONCLUSIONS MH accounts for part of AP effects of parent formula CSP in acute FS rats, mainly via ghrelin-related shared regulation coupled to BOLD signals in brain areas. This novel functionally connection of HTB following acute stress, treatment, and regulation highlights anti-depression unified theory.
Rats ; Mice ; Animals ; Brain-Derived Neurotrophic Factor/metabolism* ; Ghrelin/metabolism* ; Antidepressive Agents/therapeutic use* ; Hippocampus ; Stress, Psychological ; Mammals/metabolism*

OBJECTIVETo investigate the effects of Ghrelin on the expression of acyl coenzyme A:cholesterol acyltransferases-1 (ACAT-1) in THP-1 derived foam cells.

METHODSThe human monocytic leukemia cell line (THP-1) was chosen in our study. The differentiation of THP-1 cells into macrophages was induced by phorbol 12-myristate 13-acetate. Macrophages were then incubated with oxidized LDL (ox-LDL) to generate foam cells. Ghrelin and [D-Lys3]-GHRP-6, the special antagonist of growth hormone secretagogue receptor (GHS-R), were treated during foam cells formation. The ACAT-1 protein and mRNA levels were detected by Western blot and RT-PCR. The effect of variance of cholesterol content was measured by zymochemistry via-fluorospectrophotometer.

RESULTSGhrelin reduced the content of cholesterol ester in foam cells obviously. ACAT-1 protein and mRNA levels were also decreased. The antagonist of GHS-R inhibited the effects of Ghrelin on ACAT-1 expression in dose-dependent manner. The ACAT-1 mRNA levels of the GHS-R specific antagonist groups (10(-5), 5 x 10(-5), 10(-4) mol/L) were 1.14 +/- 0.04, 1.58 +/- 0.03, 2.40 +/- 0.16, significantly higher than that of the Ghrelin group (0.89 +/- 0.05). And the protein expressions were 1.25 +/- 0.09, 1.77 +/- 0.11, 2.30 +/- 0.09, also higher than that of the Ghrelin group (0.86 +/- 0.08).

CONCLUSIONSGhrelin might interfere atherosclerosis by down-regulating the expression of ACAT-1 via GHS-R pathway.

Acetyl-CoA C-Acetyltransferase ; metabolism ; Acyl Coenzyme A ; metabolism ; Blotting, Western ; Cell Line, Tumor ; Cholesterol ; metabolism ; Down-Regulation ; Foam Cells ; metabolism ; Ghrelin ; physiology ; Humans ; RNA, Messenger ; metabolism ; Receptors, Ghrelin ; physiology ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; Spectrophotometry