98th Annual Meeting DOG 2000

P 8

Rescue effects of subretinally transplanted stem cells on the inherited photoreceptor degeneration in RCS rats

A. Hueber*, G. Thumann*, T. Luther*, K. Addicks#, K. U. Bartz-Schmidt*, U. Schraermeyer*

The Royal College of Surgeons (RCS) rat is an animal model for retinal pigment cell related photoreceptor degeneration, such as the age related macular degeneration in human. The RCS rat is committed to a progressive retinal degeneration during the early postnatal embryonic period. Aim of the study was to investigate the effect of subretinally transplanted embryonal stem cells on the photoreceptor cell degeneration in RCS rats. Embryonic stem cells of the inner cell mass of the blastocyst were differentiated to neural precursor cells and transplanted into the subretinal space of RCS rats (20 days of age). Transplanted and non transplanted age matched control animals were sacrificed between 3 days and 2 month after the time point of transplantation. Eyes were enucleated and photoreceptor degeneration was quantified by the determination of the thickness of the outer nuclear layer by light and electron microscopy. In the transplanted eyes up to 8 rows of photoreceptor cell nuclei were observed 2 month after transplantation, whereas the outer nuclear layer of non treated control animals degenerated completely in the same period of time. Transplantation of precursor cells appears to be a means of delaying photoreceptor cell degeneration in RCS rats.

Dept. of Ophthalmology* and Dept. of Anatomy I#, University of Cologne, Joseph-Stelzmann-Strasse 9, D - 50931 Cologne, Germany