ObjectiveTo detect the induction of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) production in immunostimulated retinal pigment epithelial (RPE) cells to seek for the supplying of the arginine, a substrate for NOS; as well as the effects of produced NO on the tight junction of RPE-J cells. MethodsRat′s RPE-J cells were treated with interferon-γ(INF-γ), tumor necrosis factor-α(TNF-α) and lipopolysaccharide (LPS), and Northern and Western blotting were applied to analyze the expression of the citrulline-NO cycle enzymes and related enzymes and the effect of dexamethasone and cyclic adenosine monophosphate (camp) on the expression of iNOS. Immunocytochemistry reaction and Western blotting were used to evaluate the effect of produced NO on the tight junctions of RPE-J cells.ResultsiNOS and argininosuccinate synthetase (AS) were highly induced at both mRNA and protection levels in immunostimulated RPE cells while arginiosuccinate lyase (AL) was not induced. NO was produced by cells after stimulation with TNFα, IFNγ and LPS. The induction of iNOS mRNA and the production of NO by these immunostimulated cells was further enhanced by cAMP. NO was produced from citrulline as well as from arginine. And the produced NO impaired the tight junction of RPE-J cells, decreased the production of tight junction related protein ZO-1.ConclusionIn activated RPE-J cells, citrullinearginine recycling is important for NO production, and the produced NO weakened the function of tight junction of RPE-J cells.(Chin J Ocul Fundus Dis, 2005,21:32-36)
Objective To determine the difference of global indices of retinal thickness at posterior pole in primary and suspected glaucoma. Methods Forty-five global indices of analysis on retinal thickness at posterior pole in every case, including 12 cases of primary open-angle glaucoma and 11 cases of suspected glaucoma were obtained by advanced retinal thickness analyzer. Every index was also compared. Results There were significant differences between primary and suspected glaucoma in foveal shape deviation (FSD), foveal corrected thickness deviation (FCTD), foveal fixation corrected thickness deviation (FFD), foveola thickness deviation (VTD), corrected foveola thickness deviation (CVTD), peri-foveal abnormally thin area (PFATN), posterior-pole pattern deviation (PPPD), and posterior-pole abnormally thin area (PPATN). Conclusion There are significant difference of morphologic indices of retinal thickness at posterior pole between primary and suspected glaucoma. (Chin J Ocul Fundus Dis, 2002, 18: 113-115)