CSF α-MSH in dementia of the Alzheimer type

We measured CSF a-melanocyte stimulating hormone-like immunoreactivity (a-MSH-LI) in 35 patients with dementia of the Alzheimer type (DAT) and in 27 healthy control subjects. Mean a-MSH-LI concentration was significantly decreased in DAT patients as compared with age-matched controls. However, when the DAT patients were analyzed according to age at onset of dementia or presence of extrapyramidal signs, α-MSH-LI concentrations remained significantly lower than in controls only in DAT patients with late onset of dementia (>65 years of age). No correlation was found between a-MSH levels and degree of mental impairment. A significant negative correlation was found between CSF concentrations of a-MSH and homovanillic acid in the group of all DAT patients (p < 0.001). These results suggest that hypothalamic neurons which produce pro-opiornelanocortin -related peptides may be involved in Alzheimer’s disease.