Objective: The aim of this study was to identify the presence of muscarinic acetylcholine receptors-1 (mAChRs-1) in human sclera in order to determine whether the sclera is a potential site of action for mAChR antagonists.
Methods: Cell lines of human scleral fibroblasts were cultured in Dulbecco Modified Eagle's Medium. Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was used to detect mRNA expression of M1 receptors in the fibroblasts. Immunocytochemistry was used to detect proteins of mAChRs in the cell lines. Immunohistochemical study was used to further detect the presence of M1 receptor in the frozen scleral sections.
Results: The cultured fibroblasts demonstrated mRNA expression of M1 receptor in RT-PCR. Protein of the M1 was present in the fibroblasts by examination of immunocytochemistry and immunohistochemistry staining.
Conclusion: This study demonstrated the presence of M1 receptor in human scleral fibroblasts at both mRNA and protein levels. This finding indicates that the sclera is a potential site of action for the currently used mAChR antagonists in prevention of human myopia.