Dopaminergic regulation of pre-proNPY mRNA levels in the rat arcuate nucleus.

In order to study the role of dopamine on neuropeptide Y (NPY) gene expression in the rat arcuate nucleus, we evaluated the effects of haloperidol, a dopaminergic antagonist, and bromocriptine, a D2 dopamine receptor agonist, on the levels of pre-proNPY mRNA as measured by in situ hybridization. Chronic treatment with bromocriptine produced a moderate decrease of the hybridization signal, whereas haloperidol treatment resulted in a marked increase in signal intensities. These results indicate that, in the arcuate nucleus, NPY neurons are negatively regulated by dopaminergic-mediated mechanisms acting most likely through D2 receptors.