English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Neuropeptide Y (NPY), the most powerful appetite stimulant known, is synthesised in hypothalamic arcuate nucleus (ARC). NPY levels rise in the ARC and in appetite-regulating hypothalamic nuclei in food-deprived rats, and may drive compensatory hyperphagia in starvation. Circulating insulin levels fall in starvation and insulin deficiency has been postulated to stimulate hypothalamic NPY; this supports the suggestion that insulin acts on the brain to inhibit feeding. We tested this hypothesis by determining whether the increase in NPY in the ARC of starved rats was suppressed by insulin treatment.\ud\udAdult male Wistar rats were studied. Controls (n=8) were freely-fed and two other groups were food-deprived for 72 hours, both losing 20% of initial weight (p<O.OOI vs controls). One food·deprived group n=10) received insulin (5 U/kg/day) injected subcutaneously twice daily and both other groups recieved saline. Mean blood glucose values (measured in tail-prick samples) were 5.9± 0.1 mmoVI in controls, 4.6± 0.3 mmol/l in food-deprived (p<O.OOI. vs controls) and in insulin·treated 4.4± 0.3 mmol/I (p<O.OOI vs controls; NS vs food-deprived group). Final plasma insulin levels in insulin·treated rats were higher than in saline-treated food-deprived rats (46.6± 8.9 vs 28.9± 4.5 pmol/l; p<O.OOI) and comparable with controls (52.6± 16.2 pmol/l; p=NS). ARC NPY concentrations rose significantly above controls in food·deprived rats (14.18± 1.79 vs 8.4± 2.16 fmol/ug protein; p<O.OOI) and were intermediate in the insulin-treated food-deprived group (11.19± 1.36 fmol/ug protein: p<O.OI vs controls and p<O.OOI vs saline-treated, food deprived). Other hypothalamic regions showed no differences between groups.\ud\udInsulin therefore antagonises fasting·induced increases in NPY concentrations in the ARC. This is consistent with the hypotheses that insulin deficiency stimulates hypothalamic NPY synthesis, and that peripheral insulin acts as a satiety factor by inhibiting hypothalamic NPY

clinical science

Is Insulin a satiety Signal? Insulin Treatment Antagonises Starvation-Induced Increases in Neuropeptide Y Concentrations in the Arcuate Nucleus of the Rat Hypothalamus