Regulation of NPY and alpha-MSH expression by estradiol in the arcuate nucleus of Wistar female rats: a stereological study

• Type: Article in International Scientific Journal
• Date: 2016

Authors

Reboucas, ECC (Author) Other; Leal, S (Author) Other; Sa, SI (Author) FMUP

Journal

Title: Neurological Research

Vol. 38

Pages: 740-747

ISSN: 0161-6412

Publisher: Taylor & Francis

Indexing

ISI Web of Knowledge - 13 Citations

Scopus - 13 Citations

Other information

Authenticus ID: P-00K-ST0

DOI: 10.1080/01616412.2016.1203124

Abstract (EN): Objectives: Feeding behavior in both animals and humans is modulated by estrogens, as shown by the increased adiposity observed in women and rats upon the drop of estradiol levels at menopause. Estradiol action on food intake is mediated through its cognate receptors within several hypothalamic nuclei, namely the arcuate nucleus (ARN). The ARN contains two neuronal populations expressing peptides that exert opposing effects on the central control of feeding: the orexigenic neuropeptide Y (NPY) and the anorexigenic alpha-melanocyte-stimulating hormone (alpha-MSH). Methods: To understand the role played by estradiol in the modulation of food intake, we have used an animal model of cyclic 17 beta-estradiol benzoate (EB) administration and stereological methods to estimate the total number of neurons immunoreactive for NPY and alpha-MSH in the ARN of ovariectomized rats. Results: Present results show that the experimentally induced EB cyclicity prompted a decrease in food consumption and in body weight. Data also show that ovariectomy induced an increase in NPY expression and a decrease in alpha-MSH expression in the ARN that were reverted by EB administration. Conversely, EB blocked the expression of NPY and increased the synthesis of alpha-MSH in ARN neurons, without affecting the overall sum of NPY and alpha-MSH neurons. Discussion: These results suggest that estradiol affects food intake and, consequently, body weight gain, through an overriding mechanism superimposed in the physiological balance between both peptides in the ARN of female rats.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8