Methods Expression of connexin43 in isolated human ciliary bodies was assessed by immunohistochemistry and Western blot assays. Ciliary bodies were incubated with SNP (100 uM）for 24 hrs before connexin43 expression was determined.

Results By immunohistochemistry assay, basal connexin43 expression was detected in isolated human bodies, with the majority of the positive staining being located in the junctional cytoplastic region between pigmented epithelium (PE) and non-pigmented epithelium (NPE). Positive staining of connexin43was not seen in the ciliary muscles. Western blot revealed expression of connexin43 proteins. After incubation with SNP, the optical density connexin43 band increased significantly (P<0.05).

Conclusions The pattern of connexin43 expression in human ciliary epithelium suggests that connexin43 is involved in the construction of the gap junction between PE and NPE, and hence involved in the process of aqueous humor production. The effect of SNP on connexin43 expression suggests NO and/or its downstream signal pathways may modulate the gap junction, through which NO may be involved in the regulational mechanism of aqueous humor formation.