Abstract
The involvement of the hypothalamic melanocortin-3 and -4 (MC3/4) receptors system in the inhibitory actions of estradiol (E2) on feeding was investigated. Ovariectomized Long-Evans rats with lateral ventricular (LICV) injection cannulae were maintained on a near-physiological, cyclic schedule of E2 treatment. LICV injections of 0.5 nmol of the MC3/4 agonist MTII decreased feeding, and LICV injections of the MC3/4 antagonists SHU9119 (12.5-500 pmol) and AgRP (1.0 nmol) stimulated feeding. None of these effects was affected by E2 treatment. Thus, hypothalamic MC3/4 receptors play a physiological role in the control of feeding in female rats as in males but do not mediate E2's feeding effects during the ovarian cycle.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Agouti-Related Protein
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Animals
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Body Weight / drug effects
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Estradiol / pharmacology*
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Feeding Behavior / drug effects*
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Female
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Hypothalamus / metabolism
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Intercellular Signaling Peptides and Proteins
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Male
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Melanocyte-Stimulating Hormones / pharmacology
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Ovary / physiology
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Proteins / metabolism
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Rats
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Receptor, Melanocortin, Type 3
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Receptor, Melanocortin, Type 4
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Receptors, Corticotropin / antagonists & inhibitors
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Receptors, Corticotropin / metabolism
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Sex Factors
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alpha-MSH / analogs & derivatives*
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alpha-MSH / metabolism
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alpha-MSH / pharmacology
Substances
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Agouti-Related Protein
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Intercellular Signaling Peptides and Proteins
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Proteins
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Receptor, Melanocortin, Type 3
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Receptor, Melanocortin, Type 4
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Receptors, Corticotropin
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alpha-MSH (4-10)amide, Ac-Nle(4)-cyclo(Asp(5)-Phe(7)-Lys(10))-
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SHU 9119
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Estradiol
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alpha-MSH
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Melanocyte-Stimulating Hormones