Splenic Eumelanin Differs From Hair Eumelanin in C57BL/6 Mice

The study demonstrated that the spleens of black C57BL/6 mice contained eumelanin, which differed in paramagnetic properties from the eumelanin found in hair shafts and anagen VI skin. The presence of splenic eumelanin was inconsistent, with some spleens completely lacking the pigment. The percentage of spotted spleens decreased with the progression of telogen after hair growth. The splenic eumelanin showed similarities to synthetic dopa melanin rather than skin or hair melanin, suggesting limited degradation compared to skin/hair pigment. It was hypothesized that splenic eumelanin might partially originate from skin melanin phagocyted by Langerhans cells or macrophages and transported to the spleen.