Melanins and melanosomes from llama (Lama glama L.,)

ABSTRACT: Analysis of melanins and melanosomes in 8 hair and skin individual samples taken from adult pigmented argentine llamas was carried out. In each sample, eumelanins, pheomelanins, and alkali-soluble melanins were identified. The total amount of melanins and the amount of eumelanins both decreased from black to reddish brown color, while pheomelanins were found to be present in small quantities in each sample. Eumelanosomes appeared round and oval shaped, displaying a transverse striation clearly visible at low magnification (6,000÷10,000×). Dark brown samples were present in all four melanosomes stages. Stages I and II melanosomes appeared as large, asymmetrical vacuoles containing numerous micro vesicles randomly scattered within an amorphous proteinaceous material (vesiculo-globular bodies). A micro granular melanin deposit in the micro vesicles and in the matrix was observed at stage III. The fully melanized melanosomes (stage IV) were primarily round shaped, showing an irregular outline and the electron-dense pigment was arranged to form large clusters. In light brown melanocytes, numerous melanosomes at a different maturation stage could be found. Premelanosomes appeared ovoidal shaped, containing amorphous proteinaceous material in addition to some spotty and micro granular deposits. Mature melanosomes were fully melanized, homogeneously electron-dense, ovoid granules.