REDUCED EXPRESSION OF DOPAMINE D2-RECEPTORS ON PERIPHERAL BLOOD LYMPHOCYTES AS A MARKER FOR PROGRESSION OF SUBCORTICAL COGNITIVE IMPAIRMENTS

Abstract

Introduction. Peripheral blood lymphocytes (PBL) express neurotransmitter and neuropeptide receptors. The dopamine receptors in PBL may reflect the status of homologous brain receptors. Therefore, PBL were proposed as a model for investigating possible systemic derangement in various psychiatric disorders. Expression of PBL dopamine D2 receptors was not investigated in subcortical vascular dementia (SCVaD) as opposed to Alzheimer`s disease and range of neuropsychiatric patients. Objective. To assess the expression of dopamine D2 receptors on PBL in different stages of SCVaD formation. Patients and methods. The expression of dopamine D2 receptors was assessed on PBL in 18 patients with subcortical vascular mild cognitive impairment (SVMCI) and 10 early stages SCVaD patients by indirect immunoperoxidase method. Results. It was shown that expression of dopamine D2 receptors on PBL was reduced in concordance with severity of subcortical vascular cognitive deficit. This parameter was 19,5 (19-20) in SVMCI group and 18,5 (18-19) in SCVaD patients (Р = 0,016). It had a significant (P < 0,05) modest correlation with cognitive deficit severity according to MMSE (rs = 0,50), severity of kinetic apraxia (rs = -0,44) and attention impairments (rs = 0,40). The conclusion. The density of dopamine D2 receptors on PBL reduction could be the marker of transformation of SVMCI into SCVaD and could reflect the reduction of postsynaptic dopamine D2 receptors expression in frontal-subcortical brain regions. Key words: dopamine D2 receptors, lymphocytes, subcortical vascular dementia.

Keywords

• dopamine D2 receptors
• lymphocytes
• subcortical vascular dementia