Substance P selectively activates TNF-alpha mRNA in rat uterine immune cells: a neuroimmune link.

Substance P (SP) is a neuropeptide which influences the interaction between the nervous and immune systems. It is an important modulator of cytokines, including tumour necrosis factor-alpha (TNF-alpha) whose role during the reproductive processes has been established. We have investigated the effects of SP on TNF-alpha mRNA expression in macrophages and mast cells (MC) isolated from rat peritoneum and uterus. Cell supernatants were analysed for their histamine content as a measure of stimulation. SP alone increased TNF-alpha expression in peritoneal MC but not in peritoneal macrophages. The addition of SP resulted in a six-fold enhancement of TNF-alpha expression in uterine MC whereas no stimulation was observed in macrophages as determined by competitive polymerase chain reaction (PCR).