CART peptides

Where it comes from

Made in

The arcuate nucleus (in the POMC neurons of rodents, but not in human alpha-MSH neurons), nucleus accumbens, brainstem, pituitary, islets and gut

Sent out by

Leptin raises it; cocaine and amphetamine raise its transcript; fasting lowers it

Acts on

• Hypothalamic feeding circuits
• Reward circuits
• Islets
• Spinal cord

What it does

• Suppresses feeding when given into the brain and curbs the reward of cocaine, though mice lacking it take cocaine as readily as others ¹
• A mutation (Leu34Phe) found in one family tracks with severe obesity across three generations ²
• Promotes insulin release and beta cell survival

In medicine

• No medicine copies it or blocks it. Blood CART is a research marker with no agreed assay behind it
• Its receptor is the obstacle: GPR160 was put forward in 2021 and a later study found that CART peptide does not activate it, so the peptide is still an orphan ³

Beyond the body’s own use

• Studied for addiction and for obesity in animals. No CART peptide has been given to a person, and there is no human medicine ¹
• Nothing containing CART is approved or obtainable outside the laboratory
• The strongest human evidence is genetic rather than pharmacological: a mutation in the CART gene tracks with severe obesity and a lower resting energy expenditure across a large family ²