Naslov
Dopaminergic mechanisms in attention deficit hyperactivity disorders in children

Autori
Nedić, Gordana ; Hercigonja-Novković, Vesna ; Dodig-Ćurković, Katarina ; Ćurković, Mario ; Škledar, Marijana ; Nikolac, Matea ; Muck-Šeler, Dorotea ; Pivac, Nela

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Periodicum Biologorum, vol 112, Suppl. 1 / Vitale, Branko - Zagreb : Hrvatsko prirodoslovno društvo, Institut Ruđer Bošković, Laserplus, 2010, 34-34

Skup
6th Croatian Congress of Pharmacology with International Participation

Mjesto i datum
Opatija, Hrvatska, 15.09.2010. - 18.09.2010

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
ADHD ; platelet MAO-B ; DRD4 ; 7-repeat allele of the exon III variable number of tandem repeats

Sažetak
Introduction: Attention-deficit/hyperactivity disorder (ADHD) is a complex and multifactorial disorder characterized by three behavioral symptoms: impulsivity, hyperactivity and/or inattention. These symptoms often lead to accidents and affect interpersonal relationships by causing inappropriate behavior. Symptoms of inattention are more persistant than symptoms of hyperactivity/impulsivity. Inattention is often associated with skill deficits and academic and social dysfunction in adults with diagnosed ADHD in childhood. Altough the neurobiological basis of ADHD implies dysfunction of dopaminergic, noradrenergic and serotonergic systems, the most investigated neurotransmitter system in ADHD is the dopaminergic system. Dopamine (DA) modulates behavior and cognition via fronto-striato-cerebellar circuits and consequently pharmacotherapy of ADHD targets these systems. Monoamine oxidase (MAO) is an enzyme that catalyzes oxidative deamination of dietary amines and monoamine neurotransmitters such as dopamine. Platelet MAO (MAO-B), which is also expressed in serotonergic neurons and astrocytes, has been proposed to represent a peripheral marker for a variety of personality traits including ADHD. There are five different dopamine receptors divided in two groups (D1 like and D2 like dopamine receptors). Many studies found a significant role of the dopamine D4 receptor (DRD4) gene, specifically the 7-repeat allele of the exon III variable number of tandem repeats (VNTR), in the etiology of ADHD. Aim of our study was to determine platelet MAO-B activity and the distribution of the DRD4 genotypes in children with ADHD and in healthy children. Materials and Methods: Platelet MAO-B activity was evalueted with a spectrofluorimetric method in 87 boys and 13 girls with ADHD (DSM-IV criteria) and in 329 healthy control children (152 boys and 177 girls). DRD4 genotype was determinated using polymerase chain reaction (PCR) and agarose gel electrophoresis in 94 children with ADHD. Results: Platelet MAO-B activity was significantly lower in children with ADHD, or in children with subtypes of ADHD, compared to control children. The DRD4 variants did not differ significantly among children with ADHD. No significant association was found between platelet MAO-B activity and gender and/or particular DRD4 genotype. Conclusions: Reduced platelet MAO-B activity in children with ADHD suggests that platelet MAO-B migh be used as a biomarker of disrupted behavior in psychopathological conditions such as ADHD. Platelet MAO-B activity was not associated with DRD4 genotype. Further study on larger sample of patients is needed to clarify the role of MAO-B and DRD4 in ADHD.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti, Kliničke medicinske znanosti

POVEZANOST RADA