Plasma levels of neuropeptides in Alzheimer's disease.
BACKGROUND
In the central nervous system, several neuropeptides are believed to be involved in the pathophysiology of Alzheimer's disease (AD). Indeed, previous studies have documented that glucagon-like peptide 1 (GLP-1) possesses neurotropic properties and can reduce amyloid-beta peptide levels in the brain in vivo. Moreover, the concentrations of neuropeptide Y (NPY) seem to be altered in the cerebrospinal fluid of patients with AD and in subjects with major depression. Finally, among the modifications induced by aging, a dysregulation of the ghrelin-growth hormone (GH) system has been reported.


METHODS
We investigated the plasma concentrations of these neuropeptides in 14 subjects with AD. Data obtained from these patients were compared with data from an age- and weight-matched healthy group.


RESULTS
No significant differences were found between the two groups in relation to plasma levels of GLP-1, NPY, ghrelin and GH. Peripheral NPY concentrations were positively correlated with ghrelin levels in both groups, and with plasma GLP-1 concentration only in controls.


CONCLUSIONS
On the basis of our results, peripheral levels of these neuropeptides seem not to serve as biochemical markers of AD.
Proto
Caterina
C
OASI Institute for Research, Troina, Italy.
Romualdi
Daniela
D
Cento
Rosa Maria
RM
Spada
Rosario S
RS
Di Mento
Giuseppina
G
Ferri
Raffaele
R
Lanzone
Antonio
A
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D000544:Alzheimer Disease / Q000097:blood* / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D005260:Female; D054439:Ghrelin; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D009478:Neuropeptide Y / Q000097:blood*; D036361:Peptide Hormones / Q000097:blood*
D015415:Biomarkers; D054439:Ghrelin; D009478:Neuropeptide Y; D036361:Peptide Hormones; D019382:Human Growth Hormone; D052216:Glucagon-Like Peptide 1