1. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to inv
estigate the effects of haloperidol treatment (1 mg/kg/day for 2, 7 or 21 c
onsecutive days) on the expression of D1B and D3 dopamine receptor mRNAs in
the rat lymphocytes.
2. The expression of D1B receptor mRNA was significantly decreased after 2
days of treatment and progressively returned toward basal values at the end
of treatment. Conversely, haloperidol failed to modify the expression of l
ymphocyte D3 receptor mRNA.
3. These results indicate short-lasting dynamic changes of expression of ly
mphocyte DIB dopamine receptor mRNA by haloperidol and suggest that the eff
ects of dopamine and dopaminergic drugs on the immune system might be media
ted, at least in part, by direct interaction of these substances with dopam
ine receptors on lymphocyte membrane.