Preretinal membrane formation in rabbit eyes after intravitreal transplantation of cultured astrocytes.

Astrocytes were cultured from the cerebral cortices of newborn rabbits and were so confirmed by staining of the glial fibrillary acidic protein (GFAP). In Experiment I, the astrocytes of newborn rabbits of both sexes from one mother were pooled and suspended in a culture medium, and approximately 1-2 X 10(4) cells were injected into the vitreous cavity of one eye and the culture medium alone was injected into the fellow eye of the mother rabbit. In Experiment II, the astrocytes cultured from the cerebral cortex of a single newborn rabbit of known sex were injected into both eyes of the mother or father rabbit. In the 24 eyes receiving the astrocyte injection, 22 eyes developed preretinal membrane in 2.5 to 14 weeks: 11 eyes developed traction retinal detachment. In the 12 control eyes receiving the culture medium injection, preretinal membrane was seen only in one eye. The preretinal membrane consisted predominantly of spindle-shaped cells positively stained by the peroxidase-antiperoxidase method for GFAP staining. Electron microscopy showed that the major component cells of the preretinal membrane were astrocytes with characteristic intermediate filaments; no retinal pigment epithelial cells were observed. In Experiment II, the average frequency of sex chromatin detection was 4.6% and 55.2% in the male and female astrocyte cultures, respectively. Three groups of experiments were made, A) the female astrocytes injected into the mother's eyes, B) the male astrocytes injected into the mother's eyes and C) the female astrocytes injected into the father's eyes. The sex chromatin was found in the cells of the preretinal membrane at the average frequencies of 63.5%, 34.4% and 55.5% in Groups A, B and C, respectively. It was concluded that the astrocytes injected into the vitreous cavity proliferated and formed the preretinal membrane to a degree that caused traction retinal detachment, without involvement of the retinal pigment epithelial cells. It was also thought that the astrocytes from the retina of the adult host eyes participated to some extent in the preretinal membrane formation.