Identification of androgen receptor protein and 5 alpha-reductase mRNA in human ocular tissues

Background/aims-Androgens have been reported to influence time structural o rganisation, functional activity, and/or pathological features of many ocul ar tissues. In addition, these hormones have been proposed as a topical the rapy for such conditions as dry eye syndromes, corneal wound healing, and h igh intraocular pressure. To advance our understanding of androgen action i n the eye, the purpose of the present study was twofold: firstly, to determ ine whether tissues of the anterior and posterior segments contain androgen receptor protein, which might make them susceptible to hormone effects fol lowing topical application; and, secondly, to examine whether these tissues contain the mRNA for types 1 and/or 2 5 alpha-reductase, an enzyme that co nverts testosterone to the very potent metabolite, dihydrotestosterone. Methods-Human ocular tissues and cells were obtained and processed for hist ochemical and molecular biological procedures. Androgen receptor protein wa s identified by utilising specific immunoperoxidase techniques. The analysi s of type 1 and type 2 5 alpha-reductase mRNAs was performed by the use of RT-PCR, agarose gel electrophoresis, and DNA, sequence analysis. All immuno histochemical evaluations and PCR amplifications included positive and nega tive controls. Results-These findings show that androgen receptor protein exists in the hu man lacrimal gland, meibomian gland, cornea, bulbar and forniceal conjuncti vae, lens epithelial cells, and retinal pigment epithelial cells, In additi on, our results demonstrate that the mRNAs for types 1 and 2 5 alpha-reduct ase occur in. the human lacrimal gland, meibomian gland, bulbar conjunctiva , cornea, and RPE cells. Conclusion-These combined results indicate that multiple ocular tissues may be target sites for androgen action.