Monosodium glutamate (
MSG) treatment of neonatal mice results in a selective damage to the arcuate nucleus (
ARC) and development of
obesity with increased adiposity at sustained
body weight in the adulthood. Feeding pattern of the
MSG obese mice is unusual. Our previous results showed that after 24-h fasting,
MSG mice consumed negligible amount of food in several hours and therefore, it was impossible to register the effect of
peptides attenuating food intake such as
cholecystokinin (CCK) or
cocaine- and
amphetamine-regulated transcript (
CART) peptide. To overcome this problem, two findings were used: firstly, orexigenic effect of
neuropeptide Y (NPY) was attenuated both by CCK or
CART peptide in lean fed mice and secondly, orexigenic effect of NPY was preserved in fed rats with
MSG obesity. In this study, short-term food intake in fed lean and
MSG obese C57BL/6 male mice was measured after simultaneous central administration of orexigenic NPY with either
CART peptide or peripherally administered CCK. Anorexigenic action of exogenous
CART peptide was preserved in
MSG obese mice. On the other hand, satiety effect of exogenous CCK was completely lost in
MSG obese mice. In conclusion, effective
leptin signaling in
ARC is necessary for satiety effect of CCK.