Uptake and metabolism of a fluorescent sulfatide analogue in cultured skin fibroblasts

The sulfatide fluorescent analogue N-l&amine rhodaminyl-(12-aminododecanoyl)cerehroside 3-sulfate was admin- istered in the form of albumin complex to normal human skin tibroblasts and its metabolic fate was investigated. Ceramide, galactosylceramide, glucosylceramide, sphingomyelin and free acid, all containing the fluorophore lissamine rhodamine, have been synthesized as reference standards for the identification of the metabolic products. Ceramide appeared to be the main metabolic product present both in cell extract and medium, followed by galactosylceramide and sphingomyelin. Fluorescence microscopy of cells showed a marked perinuclear fluorescence.