ABSTRACT
PURPOSE: We aimed to compare the neuroprotective effects of brimonidine tartrate (BRT) and melatonin (MEL) on retinal ganglion cells (RGCs) in a rat glaucoma model. METHODS: Thirty-six adult Wistar albino rats were allocated into six groups: control (C), glaucoma (G), BRT, MEL, G + BRT and G + MEL. After establishing the glaucoma model, intraocular pressure (IOP) of all animals measured at day 4 and day 30 was compared statistically with day 0 and day 4, respectively. Prior to sacrification at day 30 for histological evaluation and TUNEL analysis, retrograde labeling of non-apoptotic RGCs with 3% Fluorogold was performed and RGCs were evaluated under fluorescein microscope. RESULTS: IOP measurements at day 4 were significantly higher than basal measurements in all glaucoma groups. BRT alone induced a time-dependent decrease in IOP (p < 0.05), while MEL alone failed to reduce IOP. However, both BRT and MEL reduced IOP in the presence of glaucoma at day 30 (p < 0.05). BRT treatment significantly reversed the reduced non-apoptotic RGC counts (p < 0.01) and increased TUNEL-positive RGCs (p < 0.001) to control group levels in the presence of glaucoma. However, no statistical significance was found between groups G and G + MEL considering 3% Fluorogold-labeled cell counts and apoptotic index values. CONCLUSION: Our study revealed that systemic administration of BRT also has an IOP reducing effect. MEL has no neuroprotective effect on RGCs; on the other hand, BRT acts as a neuroprotective agent against glaucomatous injury, when applied systemically.
Subject(s)
Antioxidants/pharmacology , Brimonidine Tartrate/pharmacology , Glaucoma/drug therapy , Melatonin/pharmacology , Neuroprotective Agents/pharmacology , Retinal Ganglion Cells/drug effects , Animals , Apoptosis/drug effects , Disease Models, Animal , Intraocular Pressure/drug effects , Male , Rats , Rats, Wistar , Tonometry, OcularABSTRACT
This study investigated whether a high-fructose (HFr) diet changes the morphology of seminiferous tubules (ST) in rats and resveratrol (RES) has a possible restoring effect in this sense. Fructose (30%; w/v) was administered to rats alone or together with RES (50 mg/L) in drinking water for 8 weeks. In the HFr group, destruction of the germinal epithelium led to the detection of immature germ cells in the lumen. HFr diet gave rise to a decrease in the ST diameters (p < 0.05), Johnsen's tubular biopsy score values (p < 0.001), and an increase in the apoptotic index (p < 0.05). Ultrastructurally, HFr feeding increased lipid accumulation (p < 0.01), mitochondrial damage, and acrosomal abnormalities in spermatogenic cells. Treatment of HFr -fed rats with RES improved the reduced ST diameters and overall general histological and ultrastructural abnormalities of the STs, but did not change the increased apoptotic index.
