Disease relevance of NPY

• Hypoxia increased the size of NPY neurons in vehicle treated cultures but not in ascorbate supplemented cultures containing serum free or serum supplemented medium [1].
• In the present study, the distribution of NPY mRNA was mapped in the brain of juvenile, broiler-strain chicken, and results interpreted in the context of previous data for strains that do not exhibit hyperphagia [2].
• This latter finding was attributed to the occurrence of tonic-clonic convulsions following NPY administration [3].
• The present results of changes in the hypothalamic NPY content during fasting and refeeding support the hypothesis that NPY plays a central role in regulation of energy homeostasis, with especially important effect on feeding behavior and body weight in broiler chickens [4].
• Localization of neuropeptide Y mRNA and peptide in the chicken hypothalamus and their alterations after food deprivation, dehydration, and castration [5].

Psychiatry related information on NPY

• Thus, it seems that NPY neurons located in the mediobasal hypothalamus are involved in feeding behavior but not reproductive activity [5].
• Following food deprivation for four days, perikarya-expressing NPY mRNA and peptide were markedly increased in the mediobasal hypothalamus and particularly so in the infundibular nucleus [5].
• Chicks given NPY or PYY also spent significantly less time standing while those given PYY spent significantly less time preening compared to controls [6].
• Similarly, NE did not elevate food intake but instead induced sedation and narcolepsy, a behavioral response which could be distinguished from the convulsions observed after NPY [3].

High impact information on NPY

• In the developing chick embryo, NPY stimulated vascular sprouting from preexisting blood vessels [7].
• Deletion of neuropeptide Y (NPY) 2 receptor in mice results in blockage of NPY-induced angiogenesis and delayed wound healing [7].
• Unlike vascular endothelial growth factor (VEGF), microvessels induced by NPY had distinct vascular tree-like structures showing vasodilation [7].
• Here, we report that NPY acts as a potent angiogenic factor in vivo using the mouse corneal micropocket and the chick chorioallantoic membrane (CAM) assays [7].
• As Torpedo NPY has no unique positions when compared with the other sequences, it seems to be identical to the NPY of the common ancestor of cartilaginous fishes, bony fishes, and tetrapods after 420 million years of evolution [8].

Biological context of NPY

• The predicted chicken NPY amino acid sequence differs from that of rat at only one position [8].
• To study the evolution of this peptide family, we have isolated clones encoding NPY from central nervous system cDNA libraries of chicken, goldfish, and the ray Torpedo marmorata, as well as from a chicken genomic library [8].
• Specific high-affinity binding sites exist for the latter peptide, sites which are competed for (though with less affinity) by neuropeptide Y (NPY) [9].
• Electron microscopic immunocytochemistry confirmed the neuronal phenotype of the NPY-positive cells [10].
• Cell size and relative optical density of NPY positive neurons on coverslips were measured by image analysis and ascorbate content in the cell culture on dishes was determined by HPLC [1].

Anatomical context of NPY

• We have used immunolabeling against calbindin, neuropeptide Y, and DARPP-32 (dopamine- and adenosine-related phosphoprotein, 32 kDa) for the selective marking of putative accumbens subdivisions and have followed the anterograde transport of biotinylated dextran amine injected to the nucleus tractus solitarii region of 7-day-old domestic chicks [11].
• After gonadectomy, the number of NPY-positive perikarya in the mediobasal hypothalamus was unaltered [5].
• Furthermore, the expression of NPY mRNA in the common carotid artery was confirmed by the reverse transcription-polymerase chain reaction [12].
• Few glomus cells of the carotid body, however, displayed labeling for NPY mRNA [12].
• Affinity for cerebellar membranes was virtually equivalent for the synthetic peptide LPLRFamide and FRMFamide; the binding affinities (IC50) of all fragments tested (C-terminal pentapeptides of avian PP and NPY, and FMRFamide and LPLRFamide) fell in the same approximate range [9].

Associations of NPY with chemical compounds

• However, the known orexigenic (neuropeptide Y, agouti gene-related peptide, orexin, and orexin receptor) and anorexigenic (pro-opiomelanocortin and corticotropin-releasing hormone) neuropeptide mRNA levels remained unchanged after cerulenin treatment [13].
• The neurochemical signature of the centrifugal visual neurons also varies both between and within groups: thus, several neuroactive substances used by these neurons have been identified; GABA, glutamate, aspartate, acetylcholine, serotonin, dopamine, histamine, nitric oxide, GnRH, FMRF-amide-like peptides, Substance P, NPY and met-enkephalin [14].
• Neuropeptide Y (NPY) neurons are functionally related to the reproductive axis, modulating the release of GnRH and directly enhancing GnRH-induced luteinizing hormone (LH) secretion from gonadotrophs [10].
• Contrastingly, normoxic NPY neurons were damaged by ascorbate in serum free medium and not by incubation with ascorbate in serum supplemented medium [1].
• In addition, the localization of NPY mRNA in the glomus cells was examined by in situ hybridization with digoxigenin-labeled chicken NPY cRNA probe [12].

Physical interactions of NPY

• These results suggest that central GLP-1 may interact with NPY and may be the most potent inhibitor of food intake in the chicken [15].

Regulatory relationships of NPY

• Influence of fasting and neuropeptide Y on the suppressive food intake induced by intracerebroventricular injection of glucagon-like peptide-1 in the neonatal chick [15].

Other interactions of NPY

• NPY belongs to a family of 36-amino acid peptides that also includes pancreatic polypeptide and the endocrine gut peptide YY as well as the fish pancreatic peptide Y [8].
• A dominance effect of NPY on age at first egg and an additive effect of GNRHR on the number of double-yolked eggs were found (P<0.05) [16].
• These results indicate that central ghrelin does not interact with NPY as seen in rodents, but instead inhibits food intake by interacting with the endogenous CRF and its receptor [17].
• Since the N-terminal residues of FMRFamide and LPLRFamide are not homologous with equivalent residues of APP or NPY, our results indicate that only Arg-Tyr-NH2 or Arg-Phe-NH2 sequences are necessary for binding of the carboxy terminus peptides of the PP family [9].
• Double immunostaining experiments showed that most VIP-positive cells and about half the NPY-positive cells also displayed TH-immunoreactivity [18].

Analytical, diagnostic and therapeutic context of NPY

• Northern blot analysis with the chicken NPY exon 4 probe demonstrated that a single band for NPY mRNA was present in the poly (A) + RNA isolated from the common carotid artery where the glomus cells were distributed [12].
• Bipolar electrodes were used to record EEG activity before and after IC injections of saline, NPY or NE [3].
• The purification of NPY from brains of the American alligator (Alligator mississippiensis) was achieved using reverse-phase high performance liquid chromatography (HPLC) [19].
• In this study, using fura-2 microfluorometry and fluo-3 confocal microscopy techniques for intracellular Ca2+ measurement, we attempted to verify whether the action of NPY receptor's stimulation in heart and VSM cells modulates intracellular Ca2+ and whether this effect is mediated via the Y1 receptor type [20].
• RT-PCR analysis of NPY mRNA expression in chick embryonic sympathoadrenal cells in culture showed that NGF increases sympathetic but not adrenal NPY mRNA content [21].

References