To study the expression and distribution of neuropeptide Y (NPY) and long leptin receptor (OB-Rb) in the gastrointestinal tract of giant panda, samples of three animals were collected from the key laboratory for reproduction and conservation genetics of endangered wildlife of Sichuan province, China conservation and research center for the giant panda. Paraffin sections of giant panda gastrointestinal tissue samples were observed using hematoxylin-eosin staining (HE) and strept actividin-biotin complex immunohistochemical staining (IHC). The results show that the intestinal histology of three pandas was normal and no pathological changes, and there were rich single-cell and multi-cell mucous glands, long intestinal villi and thick muscularis mucosa and muscle layer. Positive cells expressing NPY and OB-Rb were widely detected in the gastrointestinal tract by IHC methods. NPY positive nerve fibers and neuronal cell were widely distributed in submucosal plexus and myenteric plexus, especially in the former. They were arranged beaded or point-like shape. NPY positive cells were observed in the shape of ellipse and polygon and mainly located in the mucous layer and intestinal glands. OB-Rb positive cells were mainly distributed in the mucous layer and the laminae propria, especially the latter. These results confirmed that NPY and OB-Rb are widely distributed in the gut of the giant panda, which provide strong reference for the research between growth and development, digestion and absorption, and immune function.
Animals ; China ; Intestines ; metabolism ; Neuropeptide Y ; genetics ; metabolism ; Receptors, Leptin ; genetics ; metabolism ; Ursidae ; genetics ; metabolism

To directly test if elevated glucocorticoids are required for fasting-induced regulation of growth hormone (GH)-releasing hormone (GHRH), GHRH receptors (GHRH-R) and ghrelin receptors (GHS-R) expression, male rats were bilaterally adrenalectomized or sham operated. After 7 days, animals were fed ad libitum or fasted for 48 h. Bilateral adrenalectomy increased hypothalamic GHRH to 146% and decreased neuropeptide Y (NPY) mRNA to 54% of SHAM controls. Pituitary GHRH-R and GHS-R mRNA levels were decreased by adrenalectomy to 30% and 80% of sham-operated controls. In sham- operated rats, fasting suppressed hypothalamic GHRH (49%) and stimulated NPY (166%) mRNA levels, while fasting increased pituitary GHRH-R (391%) and GHS-R (218%) mRNA levels. However, in adrenalectomized rats, fasting failed to alter pituitary GHRH-R mRNA levels, while the fasting-induced suppression of GHRH and elevation of NPY and GHS-R mRNA levels remained intact. In fasted adrenalectomized rats, corticosterone replacement increased GHRH-R mRNA levels and intensified the fasting-induced decrease in GHRH, but did not alter NPY or GHS-R response. These data suggest that elevated glucocorticoids mediate the effects of fasting on hypothalamic GHRH and pituitary GHRH-R expression, while glucocorticoids are likely not the major determinant in fasting-induced increases in hypothalamic NPY and pituitary GHS-R expression.
Adrenalectomy ; Animals ; Corticosterone ; Fasting ; Glucocorticoids ; Growth Hormone ; Humans ; Male ; Neuropeptide Y ; Rats ; Receptors, Ghrelin ; Receptors, Neuropeptide ; Receptors, Pituitary Hormone-Regulating Hormone ; RNA, Messenger ; Salicylamides

BACKGROUND/AIMS: Neuropepetide Y (NPY) is involved in the regulation of several gut functions, but the neuronal action of NPY has not been fully investigated. This study was designed to investigate the effect and mechanism of action of NPY on motility in the proximal and distal rat colon. METHODS: Rat colon with an intact superior mesenteric artery was isolated. After a basal period, NPY was administered at concentrations of 14 pM, 70 pM, 140 pM, and 280 pM. Intraluminal pressures were monitored in the proximal and distal colon. The contractile response was expressed as a percent change of motility indices over the basal level. After a pre-infusion of atropine (AT), tetrodotoxin (TTX), propranolol, hexamethonium, and phentolamine, NPY was infused at a concentration of 140 pM, and pressures were monitored. RESULTS: NPY increased the colonic motility at concentrations of 14, 70, 140, and 280 pM in the proximal colon (28.5+/-28.2%, 48.4+/-34.3%, 122.9+/-97.3%, 68.2+/-28.1%, respectively) and in the distal colon (44.9+/-25.9%, 103.8+/-72.0%, 237.1+/-131.0%, 93.0+/-63.9%, respectively) in a dose-dependent manner. The enhancing effect of NPY (140 pM) on colonic motility was significantly suppressed by pretreatment with atropine, propranolol, and TTX. However, the effect of NPY was not inhibited by hexamethonium or phentolamine. CONCLUSION: NPY increases colonic motility. The enhancing effect of NPY on colonic motility may require cholinergic input via muscarinic receptors or adrenergic input via beta-receptors.
Animals ; Atropine ; Colon ; Hexamethonium ; Mesenteric Artery, Superior ; Neurons ; Neuropeptide Y ; Neuropeptides ; Phentolamine ; Propranolol ; Rats ; Receptors, Muscarinic ; Tetrodotoxin

OBJECTIVE: Lin28 has been known to control the proliferation and pluripotency of embryonic stem cells. The purpose of this study was to determine the downstream effectors of Lin28 in mouse embryonic stem cells (mESCs) by RNA interference and microarray analysis. METHODS: The control siRNA and Lin28 siRNA (Dharmacon) were transfected into mESCs. Total RNA was prepared from each type of transfected mESC and subjected to reverse transcription-polymerase chain reaction (RT-PCR) analysis to confirm the downregulation of Lin28. The RNAs were labeled and hybridized with an Affymetrix Gene-Chip Mouse Genome 430 2.0 array. The data analysis was accomplished by GenPlex 3.0 software. The expression levels of selected genes were confirmed by quantitative real-time RT-PCR. RESULTS: According to the statistical analysis of the cDNA microarray, a total of 500 genes were altered in Lin28-downregulated mESCs (up-regulated, 384; down-regulated, 116). After differentially expressed gene filtering, 31 genes were selected as candidate genes regulated by Lin28 downregulation. Among them, neuropeptide Y5 receptor and oocyte-specific homeobox 5 genes were significantly upregulated in Lin28-downregulated mESCs. We also showed that the families of neuropeptide Y receptor (Npyr) and oocyte-specific homeobox (Obox) genes were upregulated by downregulation of Lin28. CONCLUSION: Based on the results of this study, we suggest that Lin28 controls the characteristics of mESCs through the regulation of effectors such as the Npyr and Obox families.
Animals ; Chimera ; Down-Regulation ; Embryonic Stem Cells ; Genes, Homeobox ; Genome ; Humans ; Mice ; Neuropeptide Y ; Neuropeptides ; Oligonucleotide Array Sequence Analysis ; Receptors, Neuropeptide Y ; RNA ; RNA Interference ; RNA, Small Interfering ; Statistics as Topic

OBJECTIVEBenzodiazepines (BDZ) have many effects on various kinds of epilepsies, but long-term treatment with BDZ often leads to drug tolerance. This study aimed to seek drugs which can reverse the tolerance of flurazepam (FZP), and to explore the role of neuropeptide Y (NPY) in the reversal effect.

METHODSA rat model of anticonvulsant tolerance to FZP was prepared. The rats with FZP tolerance were randomly assigned to seven groups: FZP-tolerance, and nifedipine, levetiracetam, topiramate, flumazenil, L-NAME and pyridoxamine treatment groups. The tolerance to FZP was evaluated through pentylenetetrazol (PTZ) infusion into a tail vein. The latency to onset of clonic seizure and the PTZ threshold were recorded. The mRNA of NPY receptor Y2 in the hippocampus was determined by RT-PCR, and the distribution of NPY in the hippocampus was examined by immunohistochemistry.

RESULTSIn comparison with the blank control group, the average latency to the onset of clonic seizure was shortened, the average PTZ threshold decreased and the expression of NYT and NPY receptor Y2 mRNA decreased significantly in the FZP-tolerance group (p<0.01). In comparison with the FZP-tolerance group, the average latency to onset of clonic seizure was prolonged by 2 times and the average PTZ threshold doubled in the topiramate treatment group. The average latency to onset of clonic seizure was prolonged by 1 time and the average PTZ threshold increased 1 time in the nifedipine, the levetiracetam and the flumazenil treatment groups. The mRNA expression of NPY receptor Y2 increased by 1 or 2 times in the flumazenil, the nifedipine and the topiramate treatment groups when compared with the FZP-tolerance group.

CONCLUSIONSNifedipine, levetiracetam, topiramate and flumazenil can reverse the anticonvulsant tolerance to flurazepam. NPY may play a role in mediating the reversal effect.

Animals ; Anticonvulsants ; pharmacology ; Drug Tolerance ; Flurazepam ; pharmacology ; Hippocampus ; chemistry ; drug effects ; Male ; Neuropeptide Y ; analysis ; physiology ; Pentylenetetrazole ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Reaction Time ; Receptors, Neuropeptide Y ; genetics ; Seizures ; chemically induced ; drug therapy

Neuropeptide Y (NPY), a sympathetic neurotransmitter, is highly associated with baroreflex dysfunction and multiple cardiac diseases such as diabetic myocardiopathy. In the present study, we aimed to explore the role of peripheral NPY Y1 receptor (Y1R) and Y2 receptor (Y2R), which are dominantly present in peripheral cardiovascular control, in baroreflex sensitivity (BRS) of streptozotocin (STZ)-induced diabetic rats. Peripheral Y1R and Y2R were antagonized by specific antagonists (BIBP 3226 and BIIE 0246, respectively) from subcutaneously implanted ALZET mini-osmotic pump in STZ-induced diabetic rats for 4 weeks. Then baseline systolic blood pressure, heart rate, cardiac function, BRS, plasma NPY and lipid levels were evaluated. We found that STZ led to increased plasma NPY and lipid level. And the STZ-increased lipid levels were reduced by BIBP 3226 and BIIE 0246. BIBP 3226 ameliorated the aberrant BRS, but had little effect on the impaired cardiac function of the STZ rats. BIIE 0246 alleviated sodium nitroprusside (SNP)-induced but not phenylephrine (PE)-induced aberrant baroreflex control of heart rate in the STZ rats. In addition, BIIE 0246 alleviated the bradycardia, but further impaired cardiac contractility in the STZ rats. These results suggest that peripheral Y1R and Y2R play different roles in STZ-induced impairment of BRS.
Animals ; Arginine ; analogs & derivatives ; pharmacology ; Baroreflex ; Benzazepines ; pharmacology ; Blood Pressure ; Bradycardia ; Diabetes Mellitus, Experimental ; drug therapy ; physiopathology ; Heart Rate ; Myocardial Contraction ; Neuropeptide Y ; blood ; Rats ; Receptors, Neuropeptide Y ; antagonists & inhibitors ; Streptozocin

The regulation of growth hormone (GH) secretion is, to a larger extent, controlled by three hypothalamic hormones: GH-releasing hormone (GHRH), somatostatin, and ghrelin. Each binds to G protein-linked membrane receptors through which signaling occurs. We used a series of genetic and transgenic animal models with perturbations of individual compounds of the GH regulatory system to study somatotrope signaling. Impaired GH signaling is present in the lit mouse, which has a GHRH receptor (GHRH-R) mutation, and the dw rat, which has a post-receptor signaling defect. Both models also have impaired response to GH secretagogues (GHS), implying an interaction between the two signaling systems. The spontaneous dwarf rat (SDR), in which a mutation of the GH gene results in total absence of the hormone, shows characteristic changes in the hypothalamic regulatory hormones due to an absence of GH feedback and alterations in the expression of each of their pituitary receptors. Treatment of SDRs with GHRH and a GHS has allowed demonstration of a stimulatory effect GHRH on GHRH-R and GHS-R, and somatostatin receptor type 2 (sst2) expression and an inhibitory effect on sst5 expression. GH also modifies the expression of these receptors, though its effects are seen at later time periods and appear to be indirect. In the absence of GH negative feedback, both hypothalamic and pituitary expression is altered to favor stimulation of GH synthesis and release. However, in the presence of GH negative feedback, both hypothalamic and pituitary expression is altered to favor suppression of GH synthesis and release. Loss of liver insulin-like growth factor I (IGF-I) feedback on the hypothalamic-pituitary system increases GH secretion, which, in turn, stimulates liver growth. Depletion of liver-derived IGF-I increases the expression and sensitivity of pituitary GHRH-R and GHS-R. The major site of action of liver-derived IGF-I in the regulation of GH secretion is at the pituitary level. Neuropeptide Y (NPY) is not required for basal regulation of the GH axis. NPY is required for fasting-induced suppression of GHRH and SRIH expression. NPY is also required for fasting-induced augmentation of pituitary GHS-R mRNA. Overall, the results indicate a complex regulation of GH secretion in which somatotrope receptor, as well as ligand expression, exerts an important physiological role.
Animals ; Animals, Genetically Modified ; Axis ; Ghrelin ; Growth Hormone ; Hypothalamus ; Insulin-Like Growth Factor I ; Liver ; Membranes ; Mice ; Neuropeptide Y ; Rats ; Receptors, Neuropeptide ; Receptors, Pituitary Hormone-Regulating Hormone ; Receptors, Somatostatin ; RNA, Messenger ; Somatostatin

BACKGROUND/AIMS: Interactions between H. pylori and gastric epithelial cells contribute to gastric inflammation and epithelial damage. This study was performed to evaluate the gene expression profile of AGS cells by adhesion of H. pylori. METHODS: Changes in AGS cell gene expression induced by co-culturing with H. pylori (G69a strain) (4, 12, 24, 48 hours) were monitored using oligonucleotide microarray. Real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed for data validation by the Assay-on-Demand Gene Expression product method. RESULTS: A total of 270 (2.66%) and 19 genes (0.19%) were up-regulated in AGS cells by H. pylori adhesion. Gene ontology analysis showed that up-regulated genes were categorized into endolipidase activity (17 genes), receptor binding (17 genes), integrin binding (4 genes), and two down-regulated genes into GTP binding category. The expression levels of 20 up- and 5 down-regulated genes were quantified by real-time RT-PCR. Sixteen genes involving cytokine activity (IL8, IL1B, TNF), hydrolase activity (PTP4A1, ERCC1, CASP8, CASP7, ACIN1), VIP receptor activity (VIPR2), and neuropeptide Y receptor activity (GPR83) were confirmed to be up-regulated. Five genes, namely, ARF3, M17S2, DDB2, AWP1, and WTAP were confirmed to be down-regulated. CONCLUSIONS: Host genes are significantly changed by H. pylori adhesion, which might explain the gastroduodenal pathogenesis induced by H. pylori infection.
Epithelial Cells ; Gene Expression* ; Gene Ontology ; Guanosine Triphosphate ; Helicobacter pylori* ; Helicobacter* ; Inflammation ; Oligonucleotide Array Sequence Analysis ; Receptors, Neuropeptide Y ; Receptors, Vasoactive Intestinal Peptide ; Transcriptome*

The existence of opioid receptors in mammalian cerebellum except human, has not been clearly understood. In the present study, we found that NPY was inducible by morphine in the mouse cerebellar granular and Purkinje cell layers. We performed in situ RT-PCR and immunohistochemistry to characterize the NPY expression. The increase of NPY gene expression by morphine (30 mg/kg, i.p.) was inhibited by pretreatment with not only naloxone (100 mg/kg, i.p.) but also a noncompetitive NMDA antagonist, MK-801 (0.3 mg/kg, i.p.). The competitive NMDA antagonist, AP-5 (0.9 mg/kg, i.p.) slightly attenuated the increased NPY expression by morphine. Also, the finding similar to morphine was shown by NMDA (70 mg/kg, i.p.) treatment. Our results indicate that NPY was inducible by morphine and this might reflect activation of NMDA receptors in granule cells that relay mossy fiber inputs to Purkinje cells via parallel fibers.
Animals ; Cerebellum* ; Dizocilpine Maleate ; Gene Expression ; Humans ; Immunohistochemistry ; Mice* ; Morphine* ; N-Methylaspartate* ; Naloxone ; Negotiating* ; Neuropeptide Y* ; Neuropeptides* ; Purkinje Cells ; Receptors, N-Methyl-D-Aspartate ; Receptors, Opioid

Accumulating evidence indicates an important role of hippocampal dendrite atrophy in the development of depression, while neuropeptide Y (NPY) participates in hippocampal dendrite growth. The present study was aimed to investigate the relationship between NPY and nitric oxide synthase (NOS) in chronic unpredictable mild stress (CUMS)-induced depression. CUMS-induced depression model was established in Sprague-Dawley rats. Intrahippocampal microinjections of NPY, NPY-Y1 receptor antagonist GR231118 and non-specific NOS inhibitor N-nitro-L-arginine methyl ester (L-NAME) were respectively adopted by rat brain stereotaxic coordinates. The behavioral observations were conducted by sucrose consumption test, open field test and forced swimming test. The expressions of NPY, neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) in hippocampus were detected by immunohistochemistry. The results showed that, compared with the control group, rats receiving CUMS for 21 d or intrahippocampal microinjection of GR231118 showed a significant reduction in body weight and depression-like behavior, which included reductions in sucrose preference, locomotor activity, rearing and grooming in open field test, and increased duration of immobility in forced swimming test. Moreover, the expression of NPY significantly decreased (P<0.01), while the expressions of nNOS and iNOS increased obviously in the hippocampal dentate gyrus (DG) and CA3 regions (P<0.01). Intrahippocampal microinjections of NPY prevented the depression-like behavioral changes induced by CUMS and decreased the expressions of nNOS and iNOS in the hippocampal DG and CA3 regions (P<0.01). Intrahippocampal microinjections of GR231118 reduced behavioral ability of the rats dramatically and significantly increased the expressions of hippocampal nNOS and iNOS (P<0.01). Intrahippocampal microinjections of L-NAME suppressed the depression-like behavioral changes induced by CUMS or intrahippocampal microinjection of GR231118. In conclusion, reduced expression of NPY and increased expression of NOS in hippocampus may make significant contributions to CUMS-induced depression. These results suggest that the antidepressant function of NPY associates with down-regulation of NOS expression in hippocampus, possibly mediated via NPY-Y1 receptor.
Animals ; Antidepressive Agents ; pharmacology ; Behavior, Animal ; drug effects ; Depression ; Down-Regulation ; Hippocampus ; drug effects ; Microinjections ; NG-Nitroarginine Methyl Ester ; pharmacology ; Neuropeptide Y ; pharmacology ; Nitric Oxide Synthase Type I ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Peptides, Cyclic ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Neuropeptide Y ; antagonists & inhibitors