Neuropeptide Y enhances the inhibitory effects of clonidine on3H-noradrenaline release in synaptosomes isolated from the medulla oblongata of the male rat

1986 ◽  
Vol 67 (1-2) ◽  
pp. 113-124 ◽  
Author(s):  
M. Martire ◽  
K. Fuxe ◽  
G. Pistritto ◽  
P. Preziosi ◽  
L. F. Agnati
Keyword(s):  
Neuropeptide Y ◽  
Medulla Oblongata ◽  
Noradrenaline Release ◽  
Male Rat ◽  
Inhibitory Effects

scholarly journals Combining neuropeptide Y and mesenchymal stem cells reverses remodeling after myocardial infarction

2010 ◽  
Vol 298 (1) ◽  
pp. H275-H286 ◽  
Author(s):  
Yigang Wang ◽  
Dongsheng Zhang ◽  
Muhammad Ashraf ◽  
Tiemin Zhao ◽  
Wei Huang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Neuropeptide Y ◽  
Combined Treatment ◽  
Border Zone ◽  
Initiation Factor ◽  
Male Rat ◽  
Infarcted Myocardium ◽  
Adult Cardiomyocytes

Neuropeptide Y (NPY) induced reentry of differentiated rat neonatal and adult cardiomyocytes into the cell cycle. NPY also induced differentiation of bone marrow-derived mesenchymal stem cells (MSC) into cardiomyocytes following transplantation into infarcted myocardium. Rat neonatal and adult cardiomyocytes were treated in vitro with vehicle, NPY, fibroblast growth factor (FGF; 100 ng/ml), or FGF plus NPY. DNA synthesis, mitosis, and cytokinesis were determined by immunocytochemistry. NPY-induced MSC gene expression, cell migration, tube formation, and endothelial cell differentiation were analyzed. Male rat green fluorescent protein-MSC (2 × 106), pretreated with either vehicle or NPY (10−8 M) for 72 h, were injected into the border zone of the female myocardium following left anterior descending artery ligation. On day 30, heart function was assessed, and hearts were harvested for histological and immunohistochemical analyses. NPY increased 5-bromo-2′-deoxy-uridine incorporation and promoted both cytokinesis and mitosis in rat neonatal and adult myocytes. NPY also upregulated several genes required for mitosis in MSC, including aurora B kinase, FGF-2, cycline A2, eukaryotic initiation factor 4 E, and stromal cell-derived factor-1α. NPY directly induced neonatal and adult cardiomyocyte cell-cycle reentry and enhanced the number of differentiated cardiomyocytes from MSC in the infarcted myocardium, which corresponded to improved cardiac function, reduced fibrosis, ventricular remodeling, and increased angiomyogenesis. It is concluded that a combined treatment of NPY with MSC is a novel approach for cardiac repair.

scholarly journals Suppression of Basal Spontaneous Gonadotropin-Releasing Hormone Neuronal Activity during Lactation: Role of Inhibitory Effects of Neuropeptide Y

Endocrinology ◽  
2008 ◽  
Vol 150 (1) ◽  
pp. 333-340 ◽  
Author(s):  
Jing Xu ◽  
Melissa A. Kirigiti ◽  
Michael A. Cowley ◽  
Kevin L. Grove ◽  
M. Susan Smith
Keyword(s):  
Neuropeptide Y ◽  
Neuronal Activity ◽  
Fluorescent Protein ◽  
Resting Membrane Potential ◽  
Inhibitory Effects ◽  
Gnrh Neurons ◽  
Cell Current ◽  
Green Fluorescent ◽  
Hypothalamic Slices

Increased neuropeptide Y (NPY) activity drives the chronic hyperphagia of lactation and may contribute to the suppression of GnRH activity. The majority of GnRH neurons are contacted by NPY fibers, and GnRH cells express NPY Y5 receptor (Y5R). Therefore, NPY provides a neurocircuitry for information about food intake/energy balance to be directly transmitted to GnRH neurons. To investigate the effects of lactation on GnRH neuronal activity, hypothalamic slices were prepared from green fluorescent protein-GnRH transgenic rats. Extracellular loose-patch recordings determined basal GnRH neuronal activity from slices of ovariectomized control and lactating rats. Compared with controls, hypothalamic slices from lactating rats had double the number of quiescent GnRH neurons (14.51 ± 2.86 vs. 7.04 ± 2.84%) and significantly lower firing rates of active GnRH neurons (0.25 ± 0.02 vs. 0.37 ± 0.03 Hz). To study the NPY-postsynaptic Y5R system, whole-cell current-clamp recordings were performed in hypothalamic slices from control rats to examine NPY/Y5R antagonist effects on GnRH neuronal resting membrane potential. Under tetrodotoxin treatment, NPY hyperpolarized GnRH neurons from −56.7 ± 1.94 to −62.1 ± 1.83 mV; NPY’s effects were blocked by Y5R antagonist. To determine whether increased endogenous NPY tone contributes to GnRH neuronal suppression during lactation, hypothalamic slices were treated with Y5R antagonist. A significantly greater percentage of GnRH cells were activated in slices from lactating rats (52%) compared with controls (28%). These results suggest that: 1) basal GnRH neuronal activity is suppressed during lactation; 2) NPY can hyperpolarize GnRH neurons via postsynaptic Y5R; and 3) increased inhibitory NPY tone during lactation is a component of the mechanisms responsible for suppression of GnRH neuronal activity. Neuropeptide Y (NPY) directly hyperpolarizes GnRH neurons via postsynaptic NPY Y5 receptor. Increased inhibitory NPY tone during lactation is an important component of the suppression of GnRH neuronal activity.

Central Neurotransmitter Pathways for Baroreceptor-Initiated Secretion of Vasopressin

Physiology ◽  
1986 ◽  
Vol 1 (3) ◽  
pp. 90-91 ◽  
Author(s):  
WW Blessing
Keyword(s):  
Neuropeptide Y ◽  
Medulla Oblongata ◽  
Neuroendocrine Cells ◽  
Ventrolateral Medulla ◽  
Caudal Ventrolateral Medulla ◽  
Functional Integrity

Secretion of vasopressin in response to hemorrhage depends on the functional integrity of noradrenaline- and neuropeptide Y-containing neurons. The effects of microinjections of neuropharmacological agents have clarified the role of these neurons, which project directly from the caudal ventrolateral medulla oblongata to the neuroendocrine cells in the hypothalamus.

Presynaptic A2-adrenoceptors and neuropeptide Y Y2 receptors inhibit [3H]noradrenaline release from rat hypothalamic synaptosomes via different mechanisms

1995 ◽  
Vol 188 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Maria Martire ◽  
Giuseppa Pistritto ◽  
Nadia Mores ◽  
Luigi F. Agnati ◽  
Kjell Fuxe
Keyword(s):  
Neuropeptide Y ◽  
Noradrenaline Release
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