title: Genotype-independent decrease in plasma dopamine beta-hydroxylase activity in Alzheimer's disease.
abstract: The noradrenergic system is involved in the etiology and progression of Alzheimer's disease (AD) but its role is still unclear. Dopamine beta-hydroxylase (DBH) as a catecholamine-synthesizing enzyme plays a central role in noradrenaline (NA) synthesis and turnover. Plasma DBH (pDBH) activity shows wide inheritable interindividual variability that is under genetic control. The aim of this study was to determine pDBH activity, DBH (C-970T; rs1611115) and DBH (C1603T; rs6271) gene polymorphisms in 207 patients with AD and in 90 healthy age-matched controls. Plasma DBH activity was lower, particularly in the early stage of AD, compared to values in middle and late stages of the disease, as well as to control values. Two-way ANOVA revealed significant effect of both diagnosis and DBH (C-970T) or DBH (C1603T) genotypes on pDBH activity, but without significant diagnosis×genotype interaction. No association was found between AD and DBH C-970T (OR=1.08, 95% CI 1.13-4.37; p=0.779) and C1603T (OR=0.89; 95% CI 0.36-2.20; p=0.814) genotypes controlled for age, gender, and ApoE4 allele. The decrease in pDBH activity, found in early phase of AD suggests that alterations in DBH activity represent a compensatory mechanism for the loss of noradrenergic neurons, and that treatment with selective NA reuptake inhibitors may be indicated in early stages of AD to compensate for loss of noradrenergic activity in the locus coeruleus.
authors: Division of Molecular Medicine, Rudjer Boskovic Institute, Bijenicka 54, HR-10000 Zagreb, Croatia.
authors: Maja
authors: M
authors: Mustapic
authors: Paola
authors: P
authors: Presecki
authors: Nela
authors: N
authors: Pivac
authors: Ninoslav
authors: N
authors: Mimica
authors: Patrick R
authors: PR
authors: Hof
authors: Goran
authors: G
authors: Simic
authors: Vera
authors: V
authors: Folnegovic-Smalc
authors: Dorotea
authors: D
authors: Muck-Seler
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood* / Q000235:genetics*; D000704:Analysis of Variance; D016022:Case-Control Studies; D004299:Dopamine beta-Hydroxylase / Q000097:blood* / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011569:Psychiatric Status Rating Scales
chemical_list: D004299:Dopamine beta-Hydroxylase