Localization of the prostaglandin F2 alpha receptor messenger RNA and protein in the cynomolgus monkey eye.

PURPOSE To determine the distribution of the prostaglandin F2 alpha (FP) receptor within the monkey eye. METHODS The expression and localization of the FP receptor was studied by in situ hybridization and immunohistochemistry. Cryosections of the eye were hybridized with a 35S-labeled FP receptor riboprobe, and paraffin sections were immunostained with polyclonal antibodies against an FP receptor peptide. Reverse transcriptase-polymerase chain reaction (RT-PCR) was performed on cultured cell populations from the eye. RESULTS Results of the three methods largely correlated with each other. The highest expression of FP receptor mRNA and protein was found in the corneal, conjunctival, and iridial epithelium, the ciliary muscle, and ciliary processes. Iridial and choroidal melanocytes, the retina, and the optic nerve expressed lower levels of both FP receptor message and protein. Using immunohistochemistry, the FP receptor protein was found in connective tissue fibroblasts, the corneal endothelium, and the vasculature; however, FP receptor expression was not detected using in situ hybridization. With RT-PCR, cultured retinal pigment epithelial and ciliary muscle cells from the cynomolgus monkey eye were found to express the FP receptor. CONCLUSIONS The FP receptor was found to be distributed widely in the ocular tissues, suggesting an array of autocrine and paracrine functions of PGF2 alpha in the eye.