Localization of platelet-activating factor receptor messenger RNA in the rat eye.

PURPOSE To determine the distribution of platelet-activating factor (PAF) receptor in the rat eye. METHODS Platelet-activating factor receptor messenger RNA (mRNA) expression was evaluated with reverse transcription-polymerase chain reaction (RT-PCR) in RNAs from several rat ocular tissues. Distribution of the expression was determined with in situ hybridization in adult rat eye sections and a 35S-labeled complementary RNA probe synthesized from the rat PAF receptor complementary DNA. In situ hybridization was also done with sections immunostained with OX-42, a microglia marker. RESULTS RT-PCR revealed that levels of PAF receptor expression were similar among the ocular tissues studied. The in situ hybridization signals were found in the corneal epithelium, iris and ciliary body, and ganglion and microglial cells in the retina. CONCLUSIONS Platelet-activating factor receptor mRNA was ubiquitously expressed in the rat eye with relative concentration in the corneal epithelium, iris and ciliary body, and retinal ganglion and microglial cells.