Ghrelin, a hormone mainly produced and released by the stomach, has numerous functions, including releasing growth hormones, regulating appetite, and processing sugar and lipids. Researchers have made great efforts to study the relationship between ghrelin and metabolic diseases. It is believed that human butyrylcholinesterase (hBChE) could hydrolyze ghrelin to the inactive form (desacyl-ghrelin). However, the low catalytic activity of wild hBChE against ghrelin hinders the clinical application. Recently, a soluble catalytically active hBChE mutant was successfully expressed in Escherichia coli for the first time. We then adopted HotSpot Wizard 3.0 to analyze the mutant structure and rationally selected 10 mutants. Furthermore, we determined the catalytic activities of the mutants against several substrates and the thermostability of these mutants. The results showed that the mutants E197D and A199S improved catalytic activity against ghrelin by 4.6 times and 3.5 times, respectively. The findings provide clues for treating endocrine diseases with the agents for regulating ghrelin.
Ghrelin/genetics* ; Butyrylcholinesterase/genetics* ; Humans ; Escherichia coli/metabolism* ; Mutation ; Catalysis ; Recombinant Proteins/metabolism*

OBJECTIVETo observe the effect of nourishing yin removing fire Chinese herbs (NYRF-CH) on the gene expression of hypothalamic growth hormone secretion peptide (Ghrelin) and its receptor growth hormone secretion peptide receptor 1alpha (GHSR1-alpha) at the puberty onset of danazol induced female precocious rats.

METHODSForty female SD rats were randomly divided into 4 groups, i.e., the normal group (N), the model group (M), the normal saline intervention group (NS), and the NYRFCH intervention group (NI), 10 in each group. 300 microg danazol was subcutaneously injected to all rats except those in the N group to prepare precocious rat model. NYRFCH and normal saline was respectively administered to rats in the NI and the NS group from the 15th day old for 7-10 days. No treatment was given to rats in the N group. Time of rats' vulva opening was recorded. Ovary index and uterus index were calculated. Peripheral blood levels of estradiol (E2), follicle stimulating hormone (FSH), and luteinizing hormone (LH), and hypothalamic contents of gonadotropin releasing hormone (GnRH) as well as the gene expression of hypothalamic Ghrelin and GHSR1-alpha were determined. Results Compared with the N group, the vulva opening time was advanced in the model group; peripheral blood levels of E2 and LH, uterus index, hypothalamic contents of GnRH increased; peripheral blood FSH levels and mRNA levels of hypothalamic Ghrelin and GHSR1-alpha decreased (P < 0.05, P < 0.01). Compared with the M group and the NS group, the vulva opening time was not advanced in the NI group; peripheral blood levels of E2 and LH, uterus index and hypothalamic contents of GnRH obviously decreased (P < 0.05, P < 0.01); mRNA levels of hypothalamic Ghrelin and GHSR1-alpha increased (all P < 0.01). But there was no statistical difference in the hypothalamic contents of Ghrelin, or the number and activity of GHSR1-alpha (P > 0.05).

CONCLUSIONNYRFCH had regulatory effect on regulating hypothalamic Ghrelin and GHSR1-alpha at gene transcription levels.

Animals ; Drugs, Chinese Herbal ; pharmacology ; Estradiol ; Female ; Follicle Stimulating Hormone ; metabolism ; Gene Expression ; drug effects ; Ghrelin ; genetics ; Gonadotropin-Releasing Hormone ; metabolism ; Hypothalamus ; metabolism ; Luteinizing Hormone ; metabolism ; Ovary ; Puberty, Precocious ; metabolism ; Rats ; Rats, Sprague-Dawley ; Uterus

OBJECTIVETo investigate the expression of nesfatin-1/NUCB2 and ghrelin in the gastric mucosa of rats with intrauterine growth retardation (IUGR) and its significance.

METHODSThe IUGR animal model was established by feeding rats low-protein diets during their pregnancy. Newborn rats were divided into catch-up growth, non-catch-up growth and control groups. Protein and mRNA levels of nesfatin-1/NUCB2 and ghrelin in the gastric mucosa of rats were determined by RT-PCR and Western blot, respectively.

RESULTSNesfatin-1/NUCB2 mRNA and protein were expressed in the gastric mucosa of rats immediately after birth, and their expression increased in an age-dependent manner in all three groups. Furthermore, the level of nesfatin-1/NUCB2 in the catch-up growth group was higher than that in the control group before weaning, whereas there was no significant difference in nesfatin-1/NUCB2 expression between the two groups after weaning. The level of nesfatin-1/NUCB2 in the non-catch-up growth group was lower than that in the catch-up growth group during the whole observation period. The level of ghrelin in the catch-up growth group was higher than that in the control group starting from day 12 after birth, whereas there was no significant difference in ghrelin expression between the two groups after weaning. The level of ghrelin in the non-catch-up growth group was lower compared with those in the catch-up growth and control groups from days 12 to 28 after birth.

CONCLUSIONSNesfatin-1 and ghrelin are co-expressed in the gastric mucosa of rats with IUGR after birth and interact with each other to produce long-term nutritional regulation.

Age Factors ; Animals ; Calcium-Binding Proteins ; analysis ; genetics ; DNA-Binding Proteins ; analysis ; genetics ; Female ; Fetal Growth Retardation ; metabolism ; Gastric Mucosa ; chemistry ; Ghrelin ; analysis ; genetics ; Male ; Nerve Tissue Proteins ; analysis ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley

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

BACKGROUNDCyanotic patients have potential growth retardation and malnutrition due to hypoxemia and other reasons. Ghrelin is a novel endogenous growth hormone secretagogue that has effects on growth and cardiovascular activities. The aim of this study was to evaluate the plasma level and myocardial expression of ghrelin and insulin-like growth factor-1 (IGF-1) using an immature piglet model of chronic cyanotic congenital heart defects with decreased pulmonary blood flow.

METHODSTwelve weanling Chinese piglets underwent procedures of main pulmonary artery-left atrium shunt with pulmonary artery banding or sham operation as control. Four weeks later, hemodynamic parameters were measured. Enzyme-linked immunosorbent assay for plasma ghrelin and IGF-1 level measurement were performed. Ventricular ghrelin and IGF-1 mRNA expressions were measured by quantitative real-time polymerase chain reaction.

RESULTSFour weeks after surgical procedure, the cyanotic model produced lower arterial oxygen tension ((68.73 ± 15.09) mmHg), arterial oxygen saturation ((82.35 ± 8.63)%), and higher arterial carbon dioxide tension ((51.83 ± 6.12) mmHg), hematocrit ((42.67 ± 3.83)%) and hemoglobin concentration ((138.17 ± 16.73) g/L) than the control piglets ((194.08 ± 98.79) mmHg, (96.43 ± 7.91)%, (36.9 ± 4.73) mmHg, (31.17 ± 3.71)%, (109.83 ± 13.75) g/L) (all P < 0.05). Plasma ghrelin level was significantly higher in the cyanotic model group in comparison to the control (P = 0.004), and the plasma IGF-1 level was significantly lower than control (P = 0.030). Compared with control animals, the expression of ghrelin mRNAs in the ventricular myocardium was significantly decreased in the cyanotic model group (P = 0.000), and the expression of IGF-1 mRNAs was elevated (P = 0.001).

CONCLUSIONSChronic cyanotic congenital heart defects model was successfully established. Plasma ghrelin level and myocardial IGF-1 mRNA expression were significantly up-regulated, while plasma IGF-1 level and myocardial ghrelin mRNA expression were down-regulated in the chronic cyanotic immature piglets. The ghrelin system may be an important part of the network regulating cardiac performance.

Animals ; Cyanosis ; blood ; metabolism ; physiopathology ; Female ; Ghrelin ; blood ; metabolism ; Heart Defects, Congenital ; blood ; metabolism ; physiopathology ; Insulin-Like Growth Factor I ; genetics ; metabolism ; Male ; Pulmonary Circulation ; physiology ; Swine

Ghrelin, an endogenous ligand for the growth hormone secretagogue (GHS) receptor, stimulates feeding and increases body weight. The primary action site of ghrelin has been reported to be the neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurons in the hypothalamic arcuate nucleus (ARC). In addition to the hypothalamus, the caudal brainstem also appears to be an important mediator for the orexigenic activity of ghrelin. However, it is not clear whether ghrelin applied directly to the caudal brainstem activates forebrain structures. The aim of this study was to determine whether recruitment of forebrain structures was required for hyperphagic responses stimulated by ghrelin delivery within the caudal brainstem. In our experiment, all rats were surgically implanted with indwelling cannulas in the dorsal vagal complex (DVC), and ghrelin (20 pmol in 0.5 μL) was delivered to the DVC. After the injection, the orexigenic response to ghrelin was recorded by Feeding and Activity Analyser, and NPY/AgRP mRNA expressions in rat hypothalamus were detected by real-time PCR. In addition, the NPY immunoreactive neurons in the ARC were assayed by immunohistochemistry. The results showed that ghrelin significantly increased cumulative food intake at 1, 2 and 3 h after ghrelin injection, maximal response occurring at 2 h after injection. NPY/AgRP mRNA levels in ARC treated with ghrelin increased significantly compared with those in control group (injected with saline). The highest levels of NPY and AgRP mRNA were detected at 2 h after injection. The total number and mean optical density of NPY-positive neurons increased in ghrelin treated rats compared with those in control group. Consistently, ghrelin's effect was most pronounced at 2 h after injection. Taken together, we conclude that the activation of NPY/AgRP neurons in the ARC is involved in the mediation of the hyperphagic response to brainstem ghrelin administration in neurologically intact rats.
Agouti-Related Protein ; genetics ; metabolism ; Animals ; Arcuate Nucleus of Hypothalamus ; metabolism ; physiology ; Brain Stem ; metabolism ; physiology ; Feeding Behavior ; drug effects ; Ghrelin ; pharmacology ; Hyperphagia ; physiopathology ; Hypothalamus ; metabolism ; physiology ; Male ; Neurons ; metabolism ; physiology ; Neuropeptide Y ; genetics ; metabolism ; Peptide Fragments ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the relationship between Ghrelin and growth hormone secretagogue receptor (GHSR) expression and the catch-up growth in rats with intrauterine growth restriction (IUGR).

METHODSThe rat model of IUGR was established by food restriction during pregnancy. The small for gestational age (SGA) and appropriate for gestational age (AGA) rat pups from the pregnant rats were used as the experimental group. The AGA rat pups from the pregnant rats without food restriction served as the control group. The samples from the stomach fundus and hypothalamus were taken postnatal days 0, 20 and 40. Ghrelin mRNA and GHSR mRNA expression were determined by real-time fluorescence quantitative PCR (real-time FQ-PCR). Ghrelin protein and GHSR protein expression were examined by immunohistochemistry (IHC).

RESULTSAt postnatal day 0, both Gherlin mRNA and protein levels in the stomach fundus were significantly higher, while GHSR mRNA expression in the hypothalamus were significantly lower in SGA rats from food restriction group than those in AGA rats from restriction and control groups. At postnatal day 20, the ghrelin protein expression in the stomach of fundus, and GHSR mRNA and protein expression in the hypothalamus in SGA catch-up rats were significantly higher than those in SGA non-catch-up growth rats and AGA rats from the control group. At postnatal day 40, there were no significant differences among SGA catch-up growth rats, SGA non-catch-up growth rats and normal AGA rats.

CONCLUSIONSGhrelin-GHSR might be involved in the physiological regulation and pathological process in IUGR rats. It is also possibly involved in the regulation of catch-up growth in the early life of SGA rats.

Animals ; Female ; Fetal Growth Retardation ; physiopathology ; Gastric Fundus ; chemistry ; Ghrelin ; analysis ; genetics ; physiology ; Growth ; Hypothalamus ; chemistry ; Immunohistochemistry ; Pregnancy ; Rats ; Receptors, Ghrelin ; analysis ; genetics

It has been suggested that Helicobacter pylori eradication may influence production of some peptides in the stomach, which can affect appetite. This hypothesis is controversial. To verify the hypothesis, we conducted this randomized controlled trial using H. pylori infected subjects without any gastrointestinal symptoms. The treatment group received triple H. pylori eradication therapy for 7 days and the control group received no medication. We measured ghrelin, obestatin and the tumor necrosis factor-alpha (TNF-alpha) mRNA levels in endoscopic biopsy specimens and the changes from baseline to follow-up. The plasma active n-octanoyl ghrelin and obestatin levels were measured in both groups. The ghrelin/obestatin ratios in plasma and gastric mRNA expression were calculated at baseline and follow-up. Ghrelin mRNA expression in the fundic mucosa after H. pylori eradication increased significantly compared to the control group (4.47+/-2.14 vs. 1.79+/-0.96, P=0.009), independent of inflammatory changes. However, obestatin mRNA expression decreased in the antral mucosa (-0.57+/-1.06 vs. 0.41+/-0.72, P=0.028). The treatment group showed a marginal increase (P=0.060) in plasma ghrelin/obestatin ratio. The TNF-alpha mRNA expression also decreased significantly with treatment. This randomized controlled trial demonstrates that H. pylori eradication increases ghrelin mRNA expression, independent of inflammatory cell changes.
Adult ; Aged ; Anti-Bacterial Agents/therapeutic use ; Female ; Gastric Mucosa/*metabolism/microbiology ; Gastroscopy ; Ghrelin/blood/genetics/*metabolism ; Helicobacter Infections/drug therapy/genetics/*metabolism ; *Helicobacter pylori ; Humans ; Male ; RNA, Messenger/metabolism ; Tumor Necrosis Factor-alpha/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 explore the protective effects of extract of Ginkgo biloba (EGB) in adriamycin (ADR)-induced heart failure (HF) and the mechanism of ghrelin peptide.

METHODWistar rats were randomly divided into three groups: control group, HF group and EGB group. ADR was injected in the rats of HF group and EGB group by caudal vein. After the last injection, the rats in EGB group were given intra-gastric administration of EGB solution (100 mg x kg(-1) x d(-1)). Three weeks later, cardiac function was detected; Ghrelin levels in plasma and myocardium were measured by radio-immunology assay (RIA); High energy phosphates (HEP) contents in myocardium were measured by HPLC; Myocardial gene expression of ghrelin was measured by RT-PCR.

RESULTCompared with control group, HF group had obviously decreased index of cardiac function, and these indexes such as +/- dp/dt max in EGB group were higher than those in ADR group. Plasma ghrelin level in HF group was higher than that in control group while myocardial ghrelin level was significantly lower than that in control group. Myocardial ATP content and gene expression of ghrelin mRNA in HF group were significantly lower than those in control group; Plasma ghrelin level in EGB group was significantly increased. Myocardial ATP content and gene expression of ghrelin mRNA in EGB group were significantly higher than those in HF group, and were closed to those of control group.

CONCLUSIONMyocardial energy dysfunction is an important reason of ADR-induced HF. EGB therapy can improve cardiac function and energy metabolism in HF rats, partly because it might increase the expression and production of ghrelin, which can promote positive energy metabolism.

Animals ; Disease Models, Animal ; Doxorubicin ; adverse effects ; Gene Expression ; drug effects ; Ghrelin ; metabolism ; Ginkgo biloba ; chemistry ; Heart Failure ; drug therapy ; genetics ; metabolism ; Humans ; Male ; Myocardium ; metabolism ; Plant Extracts ; administration & dosage ; Protective Agents ; administration & dosage ; Random Allocation ; Rats ; Rats, Wistar