The effect of intracerebroventricular infusions of ghrelin or short fasting on the gene expression and immunoreactivity of neuropeptide Y in the hypothalamic neurons in prepubertal female lambs: A morphofunctional study

Polkowska, Jolanta; Gajewska, Alina; Wańkowska, Marta; Misztal, Tomasz; Wójcik-Gładysz, Anna

doi:10.1016/j.jchemneu.2012.10.002

Cited by 6 publications

(5 citation statements)

References 48 publications

(70 reference statements)

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“…This study confirmed that during the development of a type 2 diabetes mellitus rat model (from the control group to the T2DM group), the expression of the hypothalamic neuropeptide Y increased in a time-dependent manner as the body weight and body fat elevated, which is consistent with the reports of the previous studies (Polkowska et al 2012). Therefore, neuropeptide Y serves as the most potent appetite stimulator, which can reduce energy consumption and may play a key role in the onset of both obesity and type 2 diabetes mellitus (Parker and Bloom 2012).…”

Section: Discussionsupporting

confidence: 92%

Alteration of NPY in hypothalamus and its correlation with leptin and ghrelin during the development of T2DM in a rat model

Zhang

et al. 2016

SpringerPlus

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ObjectivesThis study aimed to investigate the alteration of Neuropeptide Y (NPY) in the hypothalamus and its correlation with insulin, leptin and ghrelin during the development of a rat model of type 2 diabetes mellitus.MethodsThe type 2 diabetes mellitus model was developed in diet-induced obesity (DIO) rats followed by the intraperitoneal injection of low-dose streptozotocin (STZ, 25 mg/kg). At four time points during the development of type 2 diabetes mellitus in rats, the fasting serum insulin, leptin, and plasma ghrelin were measured and the hypothalamic neuropeptide Y (NPY) content and mRNA expression were detected in the rats, which were divided into 4 groups: normal control (NC), DIO4W, DIO8W, and T2DM; the mRNA expression of OB-Rb, and GSH-R1a in the hypothalamus were also assayed.ResultsDuring the development of the type 2 diabetes mellitus rat model, both the fasting serum levels of insulin and leptin (ng/ml) elevated significantly and the fasting plasma ghrelin concentration decreased the hypothalamic NPY (pg/mg) content significantly. NPY mRNA increased significantly in a time-dependent fashion while both the OB-Rb and the GHS-R1a mRNA of the hypothalamus decreased significantly. Hypothalamic NPY concentration was positively correlated with the changes in serum insulin and leptin and negatively correlated with plasma ghrelin.ConclusionsDuring the development of the type 2 diabetes mellitus rat model, the hypothalamic NPY content and NPY mRNA expression increased in a time-dependent manner, which was positively correlated with the changes of the serum insulin and leptin and negatively correlated with the plasma ghrelin.

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Section: Discussionsupporting

confidence: 92%

Alteration of NPY in hypothalamus and its correlation with leptin and ghrelin during the development of T2DM in a rat model

Zhang

et al. 2016

SpringerPlus

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“…Indeed, as a central orexigenic signal, ghrelin acts by affecting NPY, AgRP and orexin neuron activity (Kamegai et al, 2000;Toshinai et al, 2003), which leads to modulation of HPG axis activity. A direct stimulatory effect of exogenous ghrelin on NPY secretion in immature ewes was found in our previous research (Polkowska et al, 2012), which supports an indirect mode of ghrelin action on the GnRH network via enhancement of NPY neuronal system activity.…”

Section: Discussionsupporting

confidence: 83%

The effect of intracerebroventricular infusions of ghrelin on the secretory activity of the GnRH/LH system in peripubertal ewes

Wójcik-Gładysz¹,

Wańkowska²,

Gajewska³

et al. 2014

J. Anim. Feed Sci.

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“…Moreover, NPY neurons in the ARC nucleus are primary targets for many orexigenic and anorexigenic peripheral hormones (Gładysz, Krejci, Simůnek, & Polkowska, ; Tillet et al., ). Our previous studies confirmed that peripheral peptides, such as leptin and ghrelin, are involved in the modulation of hypothalamic appetite‐regulating network activity in sheep, and this modulation occurs via NPY neurons in the ARC nucleus (Polkowska, Gajewska, Wańkowska, Misztal, & Wójcik‐Gładysz, ; Tillet et al., ; Wójcik‐Gładysz, Wańkowska, Misztal, Romanowicz, & Polkowska, ; Wójcik‐Gładysz et al., ). Considering above information, at least one hypothalamic pathway consists of NPY neurons, and the NPY neuronal system integrates the final pathway regulating food intake (Schneeberger, Gomis, & Claret, ).…”

Section: Introductionsupporting

confidence: 73%

“…It should be emphasized that leptin‐induced changes in the NPY immunoreactivity were restricted to NPY perikarya and varicose nerve fibres located in the ARC nucleus, whereas no effect on subpopulations of NPY neurons in the PEV and paraventricular nucleus (PVN) was found (Polkowska et al., ). In contrast, centrally administered ghrelin evoked changes in all subpopulations of NPY neurons (localized in the ARC, PEV and PVN nuclei) (Polkowska et al., ). The observed differences between action of those peptides could be linked with individual peripheral hormones that convey information regarding the energetic status of the organism, and which act selectively on the neurosecretion of distinct NPY neurons subpopulations (Lopaschuk et al., ).…”

Section: Discussionmentioning

confidence: 99%

“…It is possible that these changes were due to downregulation of the NPY neuronal system. It is interesting that the diminished NPY secretion in prepubertal ewes was observed after the infusion of leptin, another peripheral anorexigenic hormone (Polkowska et al., ; Wójcik‐Gładysz et al., ). It should be emphasized that leptin‐induced changes in the NPY immunoreactivity were restricted to NPY perikarya and varicose nerve fibres located in the ARC nucleus, whereas no effect on subpopulations of NPY neurons in the PEV and paraventricular nucleus (PVN) was found (Polkowska et al., ).…”

Section: Discussionmentioning

confidence: 99%

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Does obestatin modulate the hypothalamic appetite‐regulating network in peripubertal sheep?

Szlis

Polkowska

Skrzeczyńska

et al. 2018

Animal Physiology Nutrition

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The participation of peripheral peptides in the processes regulating the food intake (energy homeostasis) at the central nervous system level remains unclear. This study focuses on the role of obestatin in neuronal activity within the hypothalamic appetite-regulating network in ruminants. The animals (n = 28) were randomly divided into two groups. The sheep in the control group received intracerebroventricular infusions of the Ringer-Locke solution, and the sheep in obestatin group were infused with obestatin (diluted in the Ringer-Locke solution) at 25 μg per 120 μl/hr. The series of four 1-hr infusions on 3 consecutive days were performed, and immediately after the experiment, the sheep were decapitated. Selected brain regions were fixed in situ for further immunohistochemical analysis, while the remaining ones were frozen for real-time RT-qPCR analysis. Obestatin infusion elicited changes in the neuropeptide Y (NPY) neuronal network in the hypothalamus. The results obtained show that exogenous obestatin evoked an increase in npy and agrpmRNA expression in the mediobasal hypothalamus (MBH), while the immunoreactivity for NPY was decreased in the arcuate and periventricular nuclei. The increase in cart and pomcmRNA expression in the MBH was also observed. Moreover, increased levels of gpr39 receptor and npy receptor 1 mRNA expression were evident in obestatin-infused sheep. Based on these results, it can be concluded that obestatin plays a role in the modulation of appetite-regulating network at the central level in sheep. The results obtained suggest that the underlying mechanism may involve the modification of the activity of NPY/AgRP and CART/α-MSH neurons in the arcuate nucleus.

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The effect of intracerebroventricular infusions of ghrelin or short fasting on the gene expression and immunoreactivity of neuropeptide Y in the hypothalamic neurons in prepubertal female lambs: A morphofunctional study

Cited by 6 publications

References 48 publications

Alteration of NPY in hypothalamus and its correlation with leptin and ghrelin during the development of T2DM in a rat model

Alteration of NPY in hypothalamus and its correlation with leptin and ghrelin during the development of T2DM in a rat model

The effect of intracerebroventricular infusions of ghrelin on the secretory activity of the GnRH/LH system in peripubertal ewes

Does obestatin modulate the hypothalamic appetite‐regulating network in peripubertal sheep?

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