Real-time reverse transcription-PCR quantitation of substance P receptor (NK-1R) mRNA.

The substance P (SP)-preferring receptor, neurokinin-1 receptor (NK-1R), has an important role in inflammation, immune regulation, and viral infection. We applied a newly developed real-time reverse transcription (RT)-PCR assay to quantify NK-1R mRNA in human neuronal cell line (NT-2N), a human B-cell line (IM9), monocyte-derived macrophages (MDM), peripheral blood lymphocytes (PBL), and human astroglioma cells (U87 MG). The NK-1R real-time RT-PCR assay has a sensitivity of 100 mRNA copies, with a dynamic range of detection between 10(2) and 10(7) copies of NK-1R gene transcripts per reaction. This assay is highly reproducible, with an intraassay coefficient variation of threshold cycle (Ct) of less than 1.9%. The NK-1R real-time RT-PCR is highly sensitive for quantitative determination of NK-1R mRNA in human immune cells (MDM and PBL) that express low levels of NK-1R mRNA. In addition, the assay has the ability to accurately quantitate the dynamic changes in NK-1R mRNA expression in interleukin-1beta-stimulated U87 MG. These data indicate that the NK-1R real-time RT-PCR has potential for a wide application in investigation of NK-1R expression at the mRNA level under physiological and pathological conditions in both the central nervous system and the immune system.