Increased neuropeptide Y secretion in the hypothalamic paraventricular nucleus of obese (fa/fa) Zucker rats

@article{Dryden1995IncreasedNY,
  title={Increased neuropeptide Y secretion in the hypothalamic paraventricular nucleus of obese (fa/fa) Zucker rats},
  author={Simon D. Dryden and Lucy C. Pickavance and Helen M. Frankish and Gareth Williams},
  journal={Brain Research},
  year={1995},
  volume={690},
  pages={185-188}
}
NPY is synthesized in the hypothalamic arcuate nucleus (ARC), and NPY injected into the paraventricular nucleus (PVN), the main site of NPY release, induces hyperphagia and reduces energy expenditure. Hypothalamic NPY mRNA and NPY levels are increased in fatty Zucker rats, consistent with increased NPY release. This could explain the hyperphagia and reduced energy expenditure, which lead to obesity in the fatty Zucker rat. We have therefore compared NPY secretion in the PVN of conscious fatty… Expand
Neuropeptide Y in the magnocellular hypothalamic neurons of obese Zucker rats
TLDR
It was found that the obese (fa/fa), in contrast to the lean (Fa/Fa) Zucker rat, displays NPY immunoreactivity in numerous MCN of the paraventricular, supraoptic as well as accessory neurosecretory nuclei, which suggests local synthesis of NPY in theMCN of obese (FA/fa) rats and involvement of hydro-osmotic disorders in the Zucker syndrome of obesity. Expand
NPY presynaptic actions are reduced in the hypothalamic mpPVN of obese (fa/fa), but not lean, Zucker rats in vitro
TLDR
NPY is less effective at the mpPVN GABA synapse in obese than in lean Zucker rats, consistent with the downregulation of NPY receptors or a reduction in receptor–effector coupling, and with the reduced sensitivity of obese rats to NPY. Expand
Physiological regulation of hypothalamic neuropeptide Y release in lean and obese rats.
TLDR
Its dysregulation in obese rats could participate in overeating and absence of feeding rhythm measured in these rats and speed up the development of their obesity. Expand
Increased feeding and neuropeptide Y (NPY) but not NPY mRNA levels in the hypothalamus of the rat following central administration of the serotonin synthesis inhibitorp-chlorophenylalanine
TLDR
It is suggested that the hyperphagia induced by pCPA is mediated by increased NPY levels and secretion in the PVN, which is further evidence for interactions between NPY and 5-HT in the control of energy homeostasis. Expand
The serotonin (5-HT) antagonist methysergide increases neuropeptide Y (NPY) synthesis and secretion in the hypothalamus of the rat
TLDR
It is concluded that methysergide induced feeding is associated with increased activity of the NPY neurons in the ARC-PVN projection, consistent with previous findings suggesting that theNPYergic ARC- PVN project may mediate, at least in part the effects of 5-HT on feeding and energy balance. Expand
Disruption in neuropeptide Y and leptin signaling in obese ventromedial hypothalamic-lesioned rats 1 This study was presented in part at the 22nd Annual Meeting of the Society for Neuroscience, Anaheim, CA, in October 1992. 1
TLDR
It is demonstrated that hyperphagia and excessive weight gain in VMH-lesioned rats are associated with an overall decrease in hypothalamic NPY and augmented leptin signaling to the hypothalamus, and this data suggests that leptin feedback action requires an intact VMH. Expand
Hypothalamic NPY status during positive energy balance and the effects of the NPY antagonist, BW1229U91, on the consumption of highly palatable energy-rich diet
TLDR
It is concluded that dietary-obese rats have underactive hypothalamic NPYergic neurons compared to lean controls, possibly as a result of increased plasma concentrations of leptin and/or insulin that directly inhibit the NPY neuronal activity. Expand
Interactions Between Leptin and Hypothalamic Neuropeptide Y Neurons in the Control of Food Intake and Energy Homeostasis in the Rat
TLDR
Leptin acts centrally to decrease NPY synthesis and NPY levels in the ARC-PVN projection; reduced NPY release in the PVN may mediate leptin's hypophagic and thermogenic actions; Conversely, NPY-induced obesity results in raised circulating leptin concentrations. Expand
Moderate Long-Term Modulation of Neuropeptide Y in Hypothalamic Arcuate Nucleus Induces Energy Balance Alterations in Adult Rats
TLDR
It is shown that a moderate overexpression of NPY was sufficient to induce diurnal over-feeding, sustained body weight gain and severe obesity in adult rats, and a dysfunction in adipocytes phenotype was observed in these obese rats. Expand
Role of hypothalamic neuropeptide Y neurons in the defective thermogenic response to acute cold exposure in fatty Zucker rats
TLDR
It is suggested that increased brown fat thermogenic capacity induced by cold in lean rats may be mediated, at least in part, by decreased neuropeptide Y release in the paraventricular nucleus, resulting in its accumulation in this site. Expand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 27 REFERENCES
Altered Neuropeptide Y Concentrations in Specific Hypothalamic Regions of Obese (fa/fa) Zucker Rats: Possible Relationship to Obesity and Neuroendocrine Disturbances
TLDR
Fundamental differences in the regulation of hypothalamic NPY between obese and lean Zucker rats are indicated and may be due to increased NPY-ergic activity in the hypothalamus. Expand
Hypothalamic neuropeptide Y receptor characteristics and NPY-induced feeding responses in lean and obese Zucker rats.
TLDR
An overactive endogenous NPYergic system in the obese (fa/fa) rat which might contribute to hyperphagia and obesity in this strain is suggested. Expand
Increased hypothalamic content of preproneuropeptide Y messenger ribonucleic acid in genetically obese Zucker rats and its regulation by food deprivation.
TLDR
Data from this study are consistent with the hypothesis that NPY projections within the hypothalamus are involved in regulating feeding behavior and weight gain, and that disturbed regulation of hypothalamic NPY expression may play a role in the etiology of obesity in the genetically obese Zucker rat. Expand
Hypothalamic neuropeptide Y (NPY) in obese Zucker rats: Implications in feeding and sexual behaviors
TLDR
As the MPOA is the only site of action of NPY on sexual behavior, the higher levels measured in this area might contribute to the defective reproductive function of the obese Zucker fa/fa rat. Expand
Neuropeptide Y receptor numbers are reduced in the hypothalamus of streptozotocin-diabetic and food-deprived rats: Further evidence of increased activity of hypothalamic NPY-containing pathways
TLDR
Insulin-deficient diabetes and food deprivation markedly increase hypothalamic NPY and NPY mRNA levels, suggesting increased activity of NPYergic pathways in the hypothalamus, which could account for hyperphagia and neuroendocrine changes in these conditions. Expand
Effect of Sustained Physiological Hyperinsulinaemia on Hypothalamic Neuropeptide Y and NPY mRNA Levels in the Rat
TLDR
Physiological hyperinsulinaemia does not apparently inhibit NPY gene expression in the arcuate nucleus, and the elevated NPY concentrations in the paraventricular nucleus could result from a reduction of its release, which would be in keeping with the reduction in food intake. Expand
Neuropeptide Y secretion increases in the paraventricular nucleus in association with increased appetite for food.
TLDR
Findings of intense and dynamic NPY neurosecretory activity within a discrete hypothalamic site in association with an increased drive for food consumption demonstrate that NPY release in the PVN is an important orexigenic signal for periodic eating behavior. Expand
Neuropeptide Y release from the paraventricular nucleus increases in association with hyperphagia in streptozotocin-induced diabetic rats.
TLDR
The findings of augmented PVN NPY release in vivo and in vitro are in accord with the hypothesis that increased NPY secretion in the PVN may be responsible for hyperphagia in diabetic rats. Expand
Neuropeptide Y, the hypothalamus, and diabetes: Insights into the central control of metabolism
TLDR
Findings suggest that NPY released in the hypothalamuss, especially from the ARC-PVN projection, plays a key role inThe hypothalamic regulation of energy balance and metabolism. Expand
Neuropeptide Y (NPY) in the area of the hypothalamic paraventricular nucleus activates the pituitary-adrenocortical axis in the rat
TLDR
An activating effect of NPY is demonstrated on the pituitary-adrenocortical axis both in conscious and anaesthetized rats which may reflect the anatomical relationship between NPY fibres and CRF neurones in the PVN. Expand
...
1
2
3
...