Interactions of amylinergic and melanocortinergic systems in the control of food intake and body weight in rodents

Diabetes Obes Metab. 2012 Jul;14(7):608-15. doi: 10.1111/j.1463-1326.2012.01570.x. Epub 2012 Feb 20.


Aims: Amylinergic and melanocortinergic systems have each been implicated in energy balance regulation. We examined the interactive effects of both systems using gene knockout and pharmacological approaches.

Methods: Acute food consumption was measured in overnight fasted male wild-type (WT) and melanocortin-4 receptor (MC-4R) deficient rats and in male and female WT and amylin knockout mice (AmyKO). Changes in food intake, body weight and composition in male WT and MC-4R deficient rats and in male diet-induced obese (DIO) rats. Pharmacological treatments included either rat amylin, murine leptin and/or the MC-4R agonist, Ac-R[CEH-dF-RWC]-amide.

Results: Amylin (10 µg/kg, IP) decreased food intake in WT but not in MC-4R deficient rats (30 and 60 min post-injection). Ac-R[CEH-dF-RWC]-amide (100 µg/kg, IP) suppressed food intake similarly in male WT and AmyKO, but was ineffective in female AmyKO. Amylin (50 µg/kg/day for 28 days) and leptin (125 µg/kg/day) synergistically reduced food intake and body weight in WT and MC-4R deficient rats to a similar extent. Amylin (100 µg/kg) combined with Ac-R[CEH-dF-RWC]-amide (100 µg/kg, IP) decreased acute food intake over 3 h to a greater extent than either agent alone in fasted mice. In DIO rats, additive anorexigenic, weight- and fat-lowering effects were observed over 12 days with the combination of rat amylin (50 µg/kg/day) and Ac-R[CEH-dF-RWC]-amide (2.3 mg/kg, SC injected daily).

Conclusions: Although amylin's acute anorexigenic effects are somewhat blunted in MC-4R deficiency and those of MC-4R agonism in amylin deficiency, these effects are surmountable with pharmacological administration lending therapeutic potential to combined amylin/melanocortin agonism for obesity.

MeSH terms

  • Animals
  • Anti-Obesity Agents / pharmacology*
  • Body Weight*
  • Disease Models, Animal
  • Drug Interactions
  • Eating*
  • Energy Metabolism
  • Female
  • Gene Knockout Techniques
  • Islet Amyloid Polypeptide / administration & dosage
  • Islet Amyloid Polypeptide / deficiency*
  • Islet Amyloid Polypeptide / pharmacology*
  • Male
  • Mice
  • Obesity / drug therapy*
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, Melanocortin, Type 4 / agonists
  • Receptor, Melanocortin, Type 4 / deficiency*


  • Anti-Obesity Agents
  • Islet Amyloid Polypeptide
  • Receptor, Melanocortin, Type 4