title: Circulating levels of GDNF in bipolar disorder.
abstract: Neurotrophic factors regulate the survival and growth of neurons, and influence synaptic efficiency and plasticity. Several studies suggest the existence of a relationship between changes in neurotrophic levels and bipolar disorder (BD). The glial cell-line derived neurotrophic factor (GDNF) influences monoaminergic neurons and glial cells, but its role in BD patients is controversial. In order to elucidate it we evaluated plasma levels of GDNF in a sample of 70 BD patients (35 in mania and 35 in euthymia) and compared with 50 healthy controls matched for age, gender and educational levels. GDNF plasma levels were measured by enzyme-linked immunosorbent assay (ELISA). Patients were assessed by a Mini-International Neuropsychiatric Interview (MINI-plus), Young Mania and Hamilton Depression Rating Scales. Plasma GDNF levels were significantly increased in BD patients in euthymia compared with BD patients in mania and healthy controls (p<0.05). GDNF plasma levels were correlated with age (ρ=0.30, p<0.05) and negatively correlated with manic symptoms in BD patients (ρ=-0.54, p<0.05). Our results provide evidence that peripheral levels of GDNF are related with different mood states in BD, reinforcing the involvement of neurotrophic factors in its physiopathology.
authors.affiliation: Programa de Pós-Graduação em Neurociências, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. izabelagb@gmail.com
authors.forename: Izabela Guimarães
authors.initials: IG
authors.lastname: Barbosa
authors.forename: Rodrigo Barreto
authors.initials: RB
authors.lastname: Huguet
authors.forename: Lirlândia Pires
authors.initials: LP
authors.lastname: Sousa
authors.forename: Mery Natali Silva
authors.initials: MN
authors.lastname: Abreu
authors.forename: Natália Pessoa
authors.initials: NP
authors.lastname: Rocha
authors.forename: Moisés Evandro
authors.initials: ME
authors.lastname: Bauer
authors.forename: Lívia A
authors.initials: LA
authors.lastname: Carvalho
authors.forename: Antônio Lúcio
authors.initials: AL
authors.lastname: Teixeira
mesh_terms: D000328:Adult; D000339:Affect / Q000502:physiology; D001714:Bipolar Disorder / Q000097:blood* / Q000503:physiopathology*; D005260:Female; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000097:blood* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000097:blood / Q000502:physiology; D009483:Neuropsychological Tests; D012720:Severity of Illness Index
chemical_list: C495039:GDNF protein, human; D051100:Glial Cell Line-Derived Neurotrophic Factor; D009414:Nerve Growth Factors