SUMMARY

Leptin is a peptide hormone encoded by the ob-gene and released by adipocytes. Over the past few years, the synthesis, regulation and effects of leptin have been extensively investigated in view of its pleiotropic role in human (patho)physio-logy. This work aimed at reviewing current morphological knowledge on leptin synthesis and secretion in adipocytes. It is concluded that the intracellular trafficking of leptin and the structural basis of leptin secretion remain to be defined. Further morphological work, especially at the ultrastructural level, is needed to firmly establish the intracellular distribution and the release pathways of the hormone