Browsing by Subject "Neuropeptide Y"

Now showing 1 - 4 of 4
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    Contribution of Baroreflex Afferent Pathway to NPY-Mediated Regulation of Blood Pressure in Rats
    (Springer, 2020-04) Liu, Yang; Zhao, Shu-Yang; Feng, Yan; Sun, Jie; Lu, Xiao-Long; Yan, Qiu-Xin; Li, Ying; Liu, Zhuo; Wang, Lu-Qi; Sun, Xun; Li, Shijun; Qiao, Guo-Fen; Li, Bai-Yan; Pediatrics, School of Medicine
    Neuropeptide Y (NPY), a metabolism-related cardiovascular factor, plays a crucial role in blood pressure (BP) regulation via peripheral and central pathways. The expression of NPY receptors (Y1R/Y2R) specific to baroreflex afferents impacts on the sexually dimorphic neural control of circulation. This study was designed to investigate the expression profiles of NPY receptors in the nodose ganglion (NG) and nucleus tractus solitary (NTS) under hypertensive conditions. To this end, rats with hypertension induced by NG-nitro-L-arginine methylester (L-NAME) or high fructose drinking (HFD), and spontaneously hypertensive rats (SHRs) were used to explore the effects/mechanisms of NPY on BP using functional, molecular, and electrophysiological approaches. The data showed that BP was elevated along with baroreceptor sensitivity dysfunction in model rats; Y1R was up- or down-regulated in the NG or NTS of male and female HFD/L-NAME groups, while Y2R was only down-regulated in the HFD groups as well as in the NG of the male L-NAME group. In SHRs, Y1R and Y2R were both down-regulated in the NTS, and not in the NG. In addition to NPY-mediated energy homeostasis, leptin-melanocortin activation may be essential for metabolic disturbance-related hypertension. We found that leptin and α-melanocyte stimulating hormone (α-MSH) receptors were aberrantly down-regulated in HFD rats. In addition, α-MSH concentrations were reduced and NPY concentrations were elevated in the serum and NTS at 60 and 90 min after acute leptin infusion. Electrophysiological recordings showed that the decay time-constant and area under the curve of excitatory post-synaptic currents were decreased by Y1R activation in A-types, whereas, both were increased by Y2R activation in Ah- or C-types. These results demonstrate that sex- and afferent-specific NPY receptor expression in the baroreflex afferent pathway is likely to be a novel target for the clinical management of metabolism-related and essential hypertension.
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    EFFECT OF POLYMORPHISM ON EXPRESSION OF THE NEUROPEPTIDE Y GENE IN INBRED ALCOHOL-PREFERRING AND -NONPREFERRING RATS
    (Elsevier, 2005) SPENCE, J. P.; LIANG, T.; HABEGGER, K.; CARR, L. G.; Department of Psychiatry, IU School of Medicine
    Using animal models of alcoholism, previous studies suggest that neuropeptide Y (NPY) may be implicated in alcohol preference and consumption due to its role in the modulation of feeding and anxiety. Quantitative trait loci (QTL) analysis previously identified an interval on rat chromosome 4 that is highly associated with alcohol preference and consumption using an F2 population derived from inbred alcohol-preferring (iP) and -nonpreferring (iNP) rats. NPY mapped to the peak of this QTL region and was prioritized as a candidate gene for alcohol-seeking behavior in the iP and iNP rats. In order to identify a potential mechanism for reduced NPY protein levels documented in the iP rat, genetic and molecular components that influence NPY expression were analyzed between iP and iNP rats. Comparing the iP rat to the iNP rat, quantitative real-time polymerase chain reaction detected significantly decreased levels of NPY mRNA expression in the iP rat in the six brain regions tested: nucleus accumbens, frontal cortex, amygdala, hippocampus, caudate-putamen, and hypothalamus. In addition, the functional significance of three previously identified polymorphisms was assessed using in vitro expression analysis. The polymorphism defined by microsatellite marker D4Mit7 in iP rats reduced luciferase reporter gene expression in SK-N-SH neuroblastoma cells. These results suggest that differential expression of the NPY gene resulting from the D4mit7 marker polymorphism may contribute to reduced levels of NPY in discrete brain regions in the iP rats.
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    Electroacupuncture Alleviates Anxiety-like Behavior in Pain Aversion Rats by Attenuating the Expression of Neuropeptide Y in Anterior Cingulate Cortex
    (Elsevier, 2022) Shao, Fangbing; Du, Junying; Wang, Sisi; Cerne, Rok; Fang, Junfan; Shao, Xiaomei; Jin, Xiaoming; Fang, Jianqiao; Anatomy, Cell Biology and Physiology, School of Medicine
    Background: Pain is considered as a multidimensional conscious experience that includes a sensory component and a negative affective-motivational component. Electroacupuncture (EA) is widely used to treat pain and pain-induced negative emotions, however, little is known about the mechanisms underlying the effect of EA. Objective: This study investigated the effect of EA on alleviating the anxiety-like behaviors in pain aversion rats and its anterior cingulate cortex (ACC) regulation mechanism. Methods: After a Freund's complete adjuvant (CFA)-conditioned place aversion (C-CPA) model was established in rats, EA treatment (2/100 Hz, 30 min, once/day, 4 days totally) was applied at bilateral Zusanli (ST36) and Kunlun (BL60) acupoints. Von Frey filaments were used to measure changes of pain withdrawal threshold (PWT) at indicated time points. Elevated zero maze (EZM) was used to investigate the changes of pain-related anxiety and CPA was used to investigate the changes of pain aversion. The protein expression levels of GAD67, PV, and NPY in ACC were detected by Western blotting. Results: Compared with the control group, the staying time in the "CFA-paired compartment" was significantly reduced, and the PWT was decreased in model group. In the EZM assessment, the distance and the time in open arm, as well as the number of open arm entries of model group were significantly lower than those in the control group. In the CPA assessment, the time spent in the "CFA-paired compartment" was significantly decreased in model group compared with control group, and EA reversed the changes in pain sensation and in pain-related emotions. Western blotting showed that the NPY level, but not the levels of GAD67 and PV, was significantly increased in the ACC of the model group compared to that of the control group. The increased expression of NPY in the ACC was significantly downregulated by EA, while sham EA produced no such effect. Conclusion: EA can effectively relieve the pain and pain-related emotions, and its mechanism may be achieved by down-regulating the expression of NPY in the ACC.
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    Neuropeptide Y-mediated sex- and afferent-specific neurotransmissions contribute to sexual dimorphism of baroreflex afferent function
    (Impact Journals, 2016-10-04) Liu, Yang; Wu, Di; Qu, Mei-Yu; He, Jian-Li; Yuan, Mei; Zhao, Miao; Wang, Jian-Xin; He, Jian; Wang, Lu-Qi; Guo, Xin-Jing; Zuo, Meng; Zhao, Shu-Yang; Ma, Mei-Na; Li, Jun-Nan; Shou, Weinian; Qiao, Guo-Fen; Li, Bai-Yan; Department of Pediatrics, IU School of Medicine
    BACKGROUND: Molecular and cellular mechanisms of neuropeptide-Y (NPY)-mediated gender-difference in blood pressure (BP) regulation are largely unknown. METHODS: Baroreceptor sensitivity (BRS) was evaluated by measuring the response of BP to phenylephrine/nitroprusside. Serum NPY concentration was determined using ELISA. The mRNA and protein expression of NPY receptors were assessed in tissue and single-cell by RT-PCR, immunoblot, and immunohistochemistry. NPY was injected into the nodose while arterial pressure was monitored. Electrophysiological recordings were performed on nodose neurons from rats by patch-clamp technique. RESULTS: The BRS was higher in female than male and ovariectomized rats, while serum NPY concentration was similar among groups. The sex-difference was detected in Y1R, not Y2R protein expression, however, both were upregulated upon ovariectomy and canceled by estrogen replacement. Immunostaining confirmed Y1R and Y2R expression in myelinated and unmyelinated afferents. Single-cell PCR demonstrated that Y1R expression/distribution was identical between A- and C-types, whereas, expressed level of Y2R was ~15 and ~7 folds higher in Ah- and C-types than A-types despite similar distribution. Activation of Y1R in nodose elevated BP, while activation of Y2R did the opposite. Activation of Y1R did not alter action potential duration (APD) of A-types, but activation of Y2R- and Y1R/Y2R in Ah- and C-types frequency-dependently prolonged APD. N-type ICa was reduced in A-, Ah- and C-types when either Y1R, Y2R, or both were activated. The sex-difference in Y1R expression was also observed in NTS. CONCLUSIONS: Sex- and afferent-specific expression of Neuropeptide-Y receptors in baroreflex afferent pathway may contribute to sexual-dimorphic neurocontrol of BP regulation.