Effects of MSH on food intake, body weight and coat color of the yellow obese mouse.
Viable yellow obese mice (Avy/a) were treated for 10 days with 5, 15, 50 or 150 micrograms/d of either alpha-MSH or desacetyl-MSH. The half-maximal effect on weight gain occurred with a dose of 5 micrograms/d for desacetyl-MSH and at a 30 fold higher level of 150 micrograms/d for alpha-MSH. In contrast, the half-maximal stimulation of eumelanin production by alpha-MSH occurred at 15 micrograms/d and with desacetyl-MSH at 150 micrograms/d, a 10-fold increase. Desacetyl-MSH produced a dose-related increase in the weight of muscle, as well as white and brown adipose tissue. Desacetyl-MSH and alpha-MSH both increased plasma corticosterone concentrations, but desacetyl-MSH was more potent. In a 2 x 2 factorial designed study, body weight was significantly increased in viable yellow mice only by treatment with desacetyl-MSH but in the lean animals, both alpha-MSH and desacetyl-MSH increased body weight. Food intake was significantly different between genotypes, and was stimulated by desacetyl-MSH. These studies demonstrate potent differences in biological actions on food intake, body weight, and a variety of organ weights between acetylated and desacetylated forms of MSH.
Shimizu
H
H
Section of Diabetes and Clinical Nutrition, University of Southern California, LAC/USC Medical Center, Los Angeles.
Shargill
N S
NS
Bray
G A
GA
Yen
T T
TT
Gesellchen
P D
PD
D000818:Animals; D001835:Body Weight / Q000187:drug effects*; D003345:Corticosterone / Q000097:blood; D005247:Feeding Behavior / Q000187:drug effects*; D006200:Hair Color / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL / Q000502:physiology; D008820:Mice, Obese / Q000502:physiology*; D009929:Organ Size / Q000187:drug effects; D010446:Peptide Fragments / Q000494:pharmacology*; D012016:Reference Values; D000521:alpha-MSH / Q000031:analogs & derivatives* / Q000494:pharmacology*
D010446:Peptide Fragments; D000521:alpha-MSH; D003345:Corticosterone