Neurotransmitter receptor expression by peripheral mononuclear cells: possible marker of neuronal damage by exposure to radiations.

Peripheral mononuclear cells (PMC) express several neurotransmitter systems. Increasing evidence suggests that PMC neurotransmitter receptors are involved in modulating immune responses. It is also thought that expression of PMC neurotransmitter receptors may reflect the status of homologous brain receptors. A problem encountered with assay of PMC neurotransmitter receptors was in developing techniques suitable for their assessment in spite of low density. In this paper we summarized findings on the expression of alpha1-adrenoceptor and dopamine receptor subtypes in human peripheral blood lymphocytes characterized by radioligand binding assay techniques and immunocytochemistry. Human lymphocytes express alpha1A-, alpha1B- and alpha1D-adrenoceptor subtypes and dopamine D3, D4 and D5 receptors. Compared to radioligand binding assay, immunocytochemistry applied to cytospin-centrifuged peripheral lymphocytes allowed to assay receptor subtypes investigated in small amounts of blood. The development of sensitive and reproducible techniques for assaying PMC neurotransmitter receptor subtypes even in small amounts of blood such as those used for diagnostic purposes may allow to analyze their sensitivity to different conditions including radiation exposure.