Alpha melanocyte stimulating hormone (MSH) in Tourette's syndrome.

The intermediate lobe of the pituitary is thought to be the primary source of alpha-melanocyte stimulating hormone (alpha-MSH). While the intermediate lobe of the human fetus contains high concentrations of alpha-MSH, the human adult pituitary is devoid of the peptide. Based on evidence implicating the hypothalamus as a site of dysfunction in Tourette's syndrome (TS), and studies suggesting that alpha-MSH may be involved in neuronal maturation, we measured plasma alpha-MSH levels in three unmedicated TS patients (aged 12 to 69), and in three age-matched controls. High plasma alpha-MSH concentrations were detected in all three patients. None of the patients showed any abnormalities in skin coloration. These findings suggest that abnormalities in the synthesis or release of alpha-MSH may be linked to the pathophysiology of TS, and also to the delay in neurodevelopmental maturation.