Mimic-Based RT-PCR Quantitation of Substance P mRNA in Human Mononuclear Phagocytes and Lymphocytes

Substance P (SP), the most extensively studied and most potent member of the tachykinin family, is a modulator in neuroimmunoregulation (1 –4 ). SP has been described as a peptide that is almost exclusively of neural origin (5 ,6 ). More recently, SP has been identified in non-neuronal cell types, including murine macrophages (7 ,8 ), human endothelial cells (9 ,10 ), eosinophils (11 ), and Leydig cells derived from human and mouse testis (12 ). We have demonstrated that human monocytes and lymphocytes express the SP gene mRNA transcripts and produce SP protein (13 –15 ).