Background:Previous studies from our laboratory have identified a novel mu opiate receptor µ[sub]3[/sub], which is expressed in several different cell types and tissues including human vascular endothelial cells, leukocytes and neural tissues. This novel µ receptor is selective for the opiate alkaloid morphine, since this receptor does not bind other opioid peptides.Material/Methods:This report details the acute affects of morphine exposure (1 µg/ml) to human leukocytes by analyzing gene expression using microarrays (Applied Biosystems). Robust estimation of the median fold change was used to identify candidates for significantly differentially expressed genes. An independent experiment using four same sample arrays was used to test the algorithm and to confirm the calculated percentage of falsely significant genes.Results:Data obtained from this study demonstrate that acute morphine exposure differentially affected genes that are involved in immune function, signal transduction, cell adhesion, and apoptosis.Conclusions:Acute morphine exposure to human leukocytes results in specific and significant alterations in gene expression.

Keywords: Gene Expression Profiling - statistics & numerical data, Receptors, Opioid, mu - metabolism, Algorithms, Gene Expression Profiling - statistics & numerical data, Gene Expression Regulation - drug effects, Interleukin-2 - genetics, Leukocytes - metabolism, Morphine - pharmacology, Oligonucleotide Array Sequence Analysis - statistics & numerical data, Receptors, Opioid, mu - metabolism, Signal Transduction - genetics, Tumor Necrosis Factor-alpha - genetics