Purpose. Progressive depigmentation )f human RPE cells is known to occur in serial cultures. However, repigmentat on has been observed to occur readily in cultured canine RPE cells. The aim of Üis study was to compare the ultrastructural and biochemical characteristics of pigment granules generated in vitro with those formed in vivo. Methods. RPE cells ~vere harvested from post-moriem canine eyes and cultured in DMEM containing antibiotics and 20% fetal bovine serum. Confluent cells at third passage were used in all aspects of this study- The ultras! rue tu re of melanosomes found ir RPE cells in vitro and in normal canine foetal and adult RPE in siiu was studied using Transmission Electron Microscopy. DOPA- oxîdase activ-ty in cultured eel s was assessed histochemically using the DOPA-re action. Antibodies recognising the tyrosinase related proteins (TRP) I and 1 were used in immunocytochemical st idies of both freshly isolated and cultured canine RPE cells. Absorption spectn were obtained for solubilised melanin granules and indirect microanalysis of t le eumelanin and pheomelanin content of granules isolated from freshly isolated a id cultured canine RPE cells was carried out by HPLC following chemical degradation. Results.The chemical content and ultraslructure of melanosomes and the melanogenic en/ymes detected were consistent wilh the formation of pheomel min in RPE cells in vitro in contrast to the eumelanin containing granules formed luring development in vivo. Conclusion. Canine RPE cell cultures may prove useful in the study of mclanogenesis regulation.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience