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.