Localization of methadone in fetal rat eye by the immunofluorescence technic.

Abstract The eyes of 28 adult methadone tolerant rats and of 56 rat neonates delivered from an additional nine methadone tolerant mothers were examined by the fluorescent antibody technic using specific methadone antiserum. Positive retinal fluorescence was seen in 32% of the neonates but was not observed in any of the adults. These findings suggest that the retinal cells of neonatal rats are still sufficiently undifferentiated so as to retain the fundamentally neural ability to bind opiates.