Endogenous substance P in corneal epithelial cells and keratocytes.

PURPOSE To detect endogenous substance P (SP) and neurokinin receptor 1 (NK1R) in cultured human corneal epithelial cells (HE) and cultured human keratocytes (HK). METHODS Messenger RNA (mRNA) expression of SP and endogenous SP in HE and HK was investigated by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay. mRNA expression of NK1R in HE and HK was investigated by RT-PCR. RESULTS The mRNA expression of SP and endogenous SP were recognized in HE and HK. Furthermore, the mRNA of NK1R was expressed in HE and HK. CONCLUSION It was suggested that endogenous SP regulates the biological functions of HE and HK in autocrine or paracrine fashion.