Molecular and biochemical analysis of ceruloplasmin expression in rabbit and rat ciliary body

Purpose : To verify the capability of rabbit and rat ciliary body to synthesize and secrete ceruloplasmin. Methods : Isolated ciliary body (CB) was cultured in the presence of [S-35]-methionine, and the incubation medium was processed for immunoprecipitation. Total RNA from CB was processed for RT-PCR, and the amplification products were sequenced. Also, sections of CB were immunostained for the localization of ceruloplasmin. Results : A labeled peptide, having a molecular weight of about 135 kDa, the expected size of ceruloplasmin, was immunopurified in the incubation media from both animal species. The RT-PCR and sequencing experiments detected the presence of ceruloplasmin mRNA in rat samples. Both layers of rabbit and rat ciliary epithelium (CE) exhibited ceruloplasmin reactivity after immunohistochemical processing. Conclusions : Taken altogether, these results indicate the CB, particularly its epithelium, as one of the possible sources of the ocular intrinsic ceruloplasmin.