In Vivo Studies

The Haskell-Luevano laboratory uses in vivo models to exam how melanocortin-specific drugs effect metabolic diseases. After a drug is created,  in vitro studies are performed in order to in vivo studies help verify the safety and effectiveness of the created drug.

Melanocortin Knock-Out Mice

The Haskell-Luevano lab contains mice with a special genetic mutation in which the melanocortin 3 receptor (MC3R) or melanocortin 4 receptor (MC4R) are knocked-out. The purpose of these animals is to mimic human metabolic diseases such as obesity and Type 2 Diabetes. These animals help us examine how melanocortin-specific effect metabolism and exercise.1,2,3

Photo of mouse Photo 2 of mouseComic of mouse

Feeding Studies

Feeding studies are a simple method to measure the effects of melanocortin agonist and antagonists in vivo. Mice receive intracerebroventricular (ICV) injections of a given drug and their hourly food intake is measured. An powerful melanocortin 4 receptor agonist will decrease food intake while an antagonist with increase food intake. This mouse model is necessary to test drugs that are synthesized in the lab. 4,5

Photo of feeding Study Photo of mouse food

Photo of feeding study

Metabolic Studies

The Haskell-Luevano lab has TSE metabolic chambers that can be used to examine individual mouse metabolic phenotypes such as respiratory exchange ratio (RER), food intake, water intake, ambulatory activity, running wheel activity and energy expenditure. 6,7

photo of lab equipment photo of metabolic graph

Exercise Studies

The Haskell-Luevano lab uses mouse running wheels to help examine how exercise influences metabolic phenotypes and gene expression in the Melanocortin pathway. 8,9

Photo of lab equipment Photo of exercise graph


  1. (
  4. Rowland, N. E., Schaub, J. W., Robertson, K. L., Andreasen, A., & Haskell-Luevano, C. (2010). Effect of MTII on food intake and brain c-Fos in melanocortin-3, melanocortin-4, and double MC3 and MC4 receptor knockout mice. Peptides, 31(12), 2314-2317. 
  7. Lensing, C. J.; Doering, S. R.; Adank, D. N.; Haskell-Luevano, C. Investigating Metabolic Gender Differences with Melanocortin Antagonist SKY 2-23-7.” Proceedings of American Peptide Symposium. 2015.
  8. (
  9. Haskell-Luevano, C., Schaub, J. W., Andreasen, A., Haskell, K. R., Moore, M. C., Koerper, L. M., . . . Xiang, Z. (2009). Voluntary exercise prevents the obese and diabetic metabolic syndrome of the melanocortin-4 receptor knockout mouse. FASEB J, 23(2), 642-655. doi: 10.1096/fj.08-109686