Paraventricular hypothalamic alpha-melanocyte-stimulating hormone and MTII reduce feeding without causing aversive effects.
alpha-Melanocyte-stimulating hormone (alpha-MSH) appears to play a tonic inhibitory role in feeding and energy storage. MTII, a specific synthetic MC3-R/MC4-R agonist, has similar effects on feeding in rats. The current studies demonstrate that PVN administration of alpha-MSH or MTII decreases nocturnal and NPY-stimulated food intake without causing aversive effects. Co-administration with NPY of 600 pmol alpha-MSH or 1 pmol MTII into the PVN caused a significant decrease in NPY-induced feeding. PVN administration of MTII or alpha-MSH at doses effective to suppress feeding did not cause conditioned taste aversion (CTA). ICV administration of alpha-MSH, however, did cause weak CTA. These results indicate that the potent effects on feeding of MC3-R and MC4-R agonists when injected into the PVN are not due to aversive effects.
Wirth
M M
MM
Minnesota Obesity Center, V.A. Medical Center, One Veterans Drive, 55417, Minneapolis, MN, USA
Olszewski
P K
PK
Yu
C
C
Levine
A S
AS
Giraudo
S Q
SQ
D000818:Animals; D004435:Eating / Q000187:drug effects / Q000502:physiology*; D007031:Hypothalamus / Q000502:physiology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D044104:Receptor, Melanocortin, Type 3; D044105:Receptor, Melanocortin, Type 4; D018043:Receptors, Corticotropin / Q000819:agonists / Q000502:physiology*; D000521:alpha-MSH / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*
D044104:Receptor, Melanocortin, Type 3; D044105:Receptor, Melanocortin, Type 4; D018043:Receptors, Corticotropin; C081720:alpha-MSH (4-10)amide, Ac-Nle(4)-cyclo(Asp(5)-Phe(7)-Lys(10))-; D000521:alpha-MSH