Abstract:Diabetes is a complex and heterogeneous disorder presently affecting more than 100 million people worldwide and causing serious socio-economic problems. Spontaneous rodent models of diabetes mellitus have proved invaluable in understanding the pathogenesis, complications, and genetic or environmental influences that increase the risks of diabetes. We have reviewed here in the development and characterization of spontaneous rodent models that displayed most features commonly associated with diabetic retinopathy.

Abstract:AIM: To study the effects of naringenin eye drops on NaIO3-induced retinal pigment epithelium (RPE) degeneration and laser-induced choroidal neovascularization (CNV) in rat eyes. · METHODS: The 35mg/kg NaIO3-induced RPE degeneration was prevented by 10g/L naringenin eye drops 3 times a day for 7 days in advance of NaIO3 injection, and then 2 to 4 weeks thereafter, RPE function was measured with C-wave of electroretinogram (ERG). The laser-induced CNV rats were treated with laser to break the Bruch's membrane and the CNV formation was prevented by 10g/L naringenin eye drops instilled 3 times a day for 2 to 4 weeks. The CNV formation was measured with fluorescein angiography (FA) and flat mount. · RESULTS: Two weeks after NaIO3 injection, the amplitude of ERG C-wave fell markedly in NaIO3 group to 53% of normal group (P <0.01). No apparent difference was observed in naringenin+NaIO3 group. Four weeks later, the NaIO3 group fell to 37% of normal group (P <0.01), while the naringenin+ NaIO3 group fell to only 57% of normal group (P <0.01). There was a 52% reversal of the ERG C-wave by naringenin as compared to NaIO3 treated group (P <0.05). Two weeks and four weeks after laser treatment, naringenin reduced the CNV formation to 53% and 49% of control group (100%) measured by FA (P <0.01). Four weeks after laser treatment, naringenin reduced the CNV formation by 47% as compared to control group measured with flat mount(P <0.01). · CONCLUSION: Naringenin can significantly protect RPE from NaIO3 induced degeneration and also prevent CNV formation.

Abstract:AIM: To investigate the mechanism of proliferation effect induced by (R,R)-XY-10 and (S,S)-XY-10 on retinal pigmented epithelial cells (ARPE-19). · METHODS: Human retinal pigmented epithelial cells (ARPE-19) and human umbilical vein endothelial cells (HUVECs) were used to investigate the effect of (R,R)-XY-10 and (S,S)-XY-10 on cell growth, and their mechanisms of proliferative action by using ERK, AKT, PI3K, Protein kinase C (PKC) and Nitric oxide synthase (NOS) inhibitors. · RESULTS: (R,R)-XY-10 and (S,S)-XY-10 dose-dependently increased ARPE-19 cell proliferation, but not on HUVECs. When treated with proliferative inhibitors, H-7 (5μmol/L), hypericin (20μmol/L), PD98059 (2μmol/L), LY294002 (50μmol/L), SH-5 (10μmol/L) and L-NAME (100μmol/L), the proliferative effect was reduced by H-7, hypericin, PD98059 and LY294002, but not by SH-5 and L-NAME. · CONCLUSION: (R,R)-XY-10 and (S,S)-XY-10 can induce cell proliferation through MAPK and PI3K dependent pathway.