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Published on: April 28, 2016
Peripheral ghrelin interacts with orexin neurons in glucostatic signalling
Andrew Solomon1, Brant A De Fanti, J Alfredo Martínez
1Department of Physiology and Nutrition, University of Navarra, 31008, Pamplona, Spain.
Regulatory Peptides
|July 10, 2007
Summary
Peripheral ghrelin signals are crucial for initiating meals and controlling appetite. Blocking ghrelin reduces hunger signals triggered by low glucose, impacting appetite control via orexin neurons.
Area of Science:
- Neuroscience
- Endocrinology
- Appetite Regulation
Background:
- Ghrelin, a key appetite-regulating hormone, interacts with glucose metabolism.
- The role of orexin and melanin-concentrating hormone (MCH) neurons in ghrelin signaling requires further elucidation.
Purpose of the Study:
- To investigate ghrelin's role in glycemia-driven appetite control.
- To explore the involvement of orexin and MCH neurons in ghrelin's orexigenic effects.
Main Methods:
- Utilized a specific anti-ghrelin antibody (AGA) to block peripheral ghrelin.
- Employed immunohistochemistry to detect c-fos positive neurons in the lateral hypothalamus (LH) and perifornical area (PFA).
- Administered insulin and 2-deoxyglucose (2-DG) to simulate changes in glucose levels.
Main Results:
- Peripheral ghrelin blockade reduced the orexigenic signals induced by insulin and 2-DG.
- Ghrelin blockade decreased c-fos immunoreactivity in the LH and PFA and reduced orexin neuron activation.
- MCH neurons did not show significant changes in response to ghrelin blockade.
Conclusions:
- Peripheral ghrelin acts as a critical hunger signal in "glucostatic" feeding regulation.
- Ghrelin influences appetite by affecting LH and PFA activity, particularly through orexin neurons.
- Ghrelin signaling contributes to energy homeostasis via its role in glucose-sensing feeding mechanisms.
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