Abstract
Abstract: :
Purpose: To set up an explant system using rat retinas in order to study and develop effective procedures for the delivery of drugs to the retina. Methods: Neural retinas freed of pigment epithelium are cultured according to Ogilvie et al (J. Neurosc. Meth. 87: 57–65, 1999) for varying periods then fixed and sectioned for light microscopy. Alternatively whole retinas or frozen sections are labelled with propidium iodide (for nuclei) or sheep anti–ABCA4 ("rim protein") and fluorescein–labelled–anti–sheep second antibody (for outer segments) and examined by epifluorescence and confocal microscopy. For uptake studies, synthetic LDL (low density lipoprotein) (Baillie et al, J Lipid Res. 43:69–73, 2002) labelled with DiO was incubated with the explants, and fluorescence uptake followed over time. Results: Retinas from 3–week–old rats were cultured for up to 8 days with retention of morphology and of outer segment ABCA4 reactivity with antisera. Freshly dissected retinas displayed active uptake of synthetic LDL. Conclusions: The rat retina can be maintained as an explant for over a week, and antibody localisation of ABCA4 used to help evaluate photoreceptor integrity. Synthetic LDL, which contains peptides binding to the apo B,E–receptor, offers the possibility of specific receptor–mediated uptake of drugs in this system. CR: P Support: WH Ross Foundation, Scottish Enterprise, Medical Research Council
Keywords: retinal culture • retina: distal (photoreceptors, horizontal cells, bipolar cells) • lipids