PT  - JOURNAL ARTICLE
AU  - Strader, April D.
AU  - Shi, Haifei
AU  - Ogawa, Ryuichi
AU  - Seeley, Randy J.
AU  - Reizes, Ofer
TI  - The Effects of the Melanocortin Agonist (MT-II) on Subcutaneous and Visceral Adipose Tissue in Rodents
AID  - 10.1124/jpet.107.123091
DP  - 2007 Sep 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 1153--1161
VI  - 322
IP  - 3
4099  - http://jpet.aspetjournals.org/content/322/3/1153.short
4100  - http://jpet.aspetjournals.org/content/322/3/1153.full
SO  - J Pharmacol Exp Ther2007 Sep 01; 322
AB  - The melanocortin system is a critical pathway in the regulation of energy balance. In this study, we analyzed the peripheral effects of the synthetic melanocortin agonist melanotan-II (MT-II) in rodents fed a low-fat or high-fat diet. MT-II-treated high-fat diet-induced obese (DIO) mice lost weight and body fat, whereas MT-II-treated low-fat-fed mice maintained their original body weight. Specifically, MT-II treatment led to a general reduction in both visceral and subcutaneous adipose tissue in high-fat-fed mice compared with Vehicle (ad libitum) controls. Vehicle-treated pair-fed DIO mice lost an equivalent amount of body weight compared with MT-II-treated mice but retained more adipose tissue. Pair-fed mice showed a reduction in visceral adipose tissue and no effect on subcutaneous adipose tissue compared with MT-II-treated mice. It is surprising that subcutaneous lean mass was significantly reduced in the pairfed mice. The data were replicated in DIO rats and indicated that MT-II treatment led to a generalized reduction in adipose tissue. These results indicate that peripheral MT-II treatment leads to weight loss that affects both the visceral and subcutaneous fat compartments. This finding illustrates the complexity of analyzing weight-reducing compounds. Although the present data suggest that the anorectic effect of MT-II is primarily a consequence of reduced food intake, the body composition data suggest that other mechanisms are involved.