Back to Search
Start Over
Neuropeptide Y is required for hyperphagic feeding in response to neuroglucopenia.
- Source :
-
Endocrinology [Endocrinology] 2004 Jul; Vol. 145 (7), pp. 3363-8. Date of Electronic Publication: 2004 Apr 02. - Publication Year :
- 2004
-
Abstract
- To investigate the role played by the orexigenic peptide, neuropeptide Y (NPY), in adaptive responses to insulin-induced hypoglycemia, we measured hypothalamic, feeding, and hormonal responses to this stimulus in both wild-type (Npy+/+) and NPY-deficient (Npy-/-) mice. After administration of insulin at a dose (60 mU ip) sufficient to cause moderate hypoglycemia (plasma glucose levels, 40 +/- 3 and 37 +/- 2 mg/dl for Npy+/+ and Npy-/- mice, respectively; P = not significant), 4-h food intake was increased 2.5-fold in Npy+/+ mice relative to saline-injected controls. By comparison, the increase of intake in Npy-/- mice was far smaller (45%) and did not achieve statistical significance (P = 0.08). Hyperphagic feeding in response to insulin-induced hypoglycemia was therefore markedly attenuated in mice lacking NPY, and a similar feeding deficit was detected in these animals after neuroglucopenia induced by 2-deoxyglucose (500 mg/kg ip). A role for NPY in glucoprivic feeding is further supported by our finding that Npy mRNA content (measured by real-time PCR) increased 2.4-fold in the hypothalamus of Npy+/+ mice by 7 h after insulin injection. Unlike the feeding deficits observed in mice lacking NPY, the effect of hypoglycemia to increase plasma glucagon and corticosterone levels was fully intact in these animals, as were both the nadir glucose value and time to recovery of euglycemia after insulin injection (P = not significant). We conclude that NPY signaling is required for hyperphagic feeding, but not neuroendocrine responses to moderate hypoglycemia.
- Subjects :
- Animals
Antimetabolites pharmacology
Blood Glucose metabolism
Corticosterone blood
Deoxyglucose pharmacology
Feeding Behavior physiology
Female
Glucagon blood
Male
Mice
Mice, Inbred Strains
Mice, Knockout
Signal Transduction physiology
Hyperphagia physiopathology
Hypoglycemia physiopathology
Hypothalamus physiology
Neuropeptide Y genetics
Subjects
Details
- Language :
- English
- ISSN :
- 0013-7227
- Volume :
- 145
- Issue :
- 7
- Database :
- MEDLINE
- Journal :
- Endocrinology
- Publication Type :
- Academic Journal
- Accession number :
- 15064281
- Full Text :
- https://doi.org/10.1210/en.2003-1727