The use of xenografting to evaluate the remyelinating potential of glial cell cultures.

Experiments in rodents have shown a potential role for glial cell transplantation as a means of influencing repair in the central nervous system of man. A crucial step in developing human therapy is to establish whether knowledge gained from studies in rodents is applicable to larger mammalian species. In order to explore this issue we examined the ability of cat glial cell cultures to remyelinate areas of ethidium-bromide-induced demyelination in the spinal cord of immunosuppressed rats and cats. Transplantation of density-gradient-isolated glial cells obtained from the forebrain of 7-day-old kittens resulted in enhanced oligodendrocyte remyelination in the rat but failed to enhance oligodendrocyte remyelination in the cat. The feasibility of enhancing oligodendrocyte remyelination in the cat lesion was demonstrated by transplanting a rat culture containing a high proportion of cells of the oligodendrocyte lineage. Tissue culture of the density-gradient-isolated cell preparations suggested that the failure of the kitten glial preparation to enhance oligodendrocyte remyelination in the cat was most probably due to its poor oligodendrocyte-generating capacity. However, our lack of understanding of the biology of feline glial cells precludes a full understanding of these experiments.