SOME ASPECTS OF MELANIN FORMATION OF MELANOCYTES CULTURED ON COLLAGEN-COATED MICROCARRIER BEADS

Melanocytes cultured on collagen-coated Cytodex 3 microcarrier Sephade x beads caused remarkable pigmentation of the beads during the period of culture when optimal density was reached. Electron microscopy of me lanocytes on the microcarriers revealed that the cells and their dendr ites invaginate into the microcarrier surface layer. Removal of the ce lls by trypsinization showed that some pigment granules were left on t he carrier surface and within the cavities present on the microcarrier surface. In order to investigate whether the pigmentation of the micr ocarriers could be a result of indole intermediates of melanogenesis p resent in the culture medium, extracts were studied by gas chromatogra phy/mass spectrometry for the presence of these compounds. Two compoun ds (5,6-dihydroxyindole-2-carboxylic acid and 6-hydroxy-5-methoxyindol e-2-carboxylic acid) so far have been identified in the medium extract s. Results indicate that microcarrier culture of melanocytes can serve as an interesting model for electron microscopy studies of melanocyte s with regard to pigmentation and cell attachment.