Meeting Abstract

P3.84  Saturday, Jan. 5  Identification of sphingolipids of the stratum corneum in lowland Tropical bird species by high performance liquid chromatography and atmospheric photo ionization mass spectrometry RO, J*; MU�OZ-GARCIA, A; WILLIAMS, J.B.; Ohio State Univ.; Ohio State Univ.; Ohio State Univ. ro.25@osu.edu

As the largest organ of the vertebrate body, the skin serves a number of functions important in survival including defense against invading pathogens, thermoregulation, and as a barrier to cutaneous water loss. In mammals and birds, this latter function is mediated primarily by the outer layer of the epidermis, the stratum corneum (SC), formed by multiple layers of cornified cells embedded in a matrix of lipids. Much of our understanding of how lipids in the SC influences water permeation through the skin comes from studies on desert birds, but little information exists on birds from other habitats. In birds, lipids in the intercellular spaces of the SC are primarily a mixture of cholesterol, free fatty acids, ceramides and cerebrosides. From previous study we found that sphingolipids, such as ceramides and cerebrosides, play important role in forming and maintaining the epidermal barrier to water vapor diffusion. In this study we used reverse phase high performance liquid chromatography (RP-HPLC) coupled with atmospheric pressure photo-ionization mass spectrometry (APPI-MS) to analyze the sphingolipids of the SC of 12 species of birds that were resident of the lowland forest in Panama. We found 6 families of ceramides, 5 families of cerebrosides and 3 families of diosylceramides in the SC of these species. We identified 6 sphingolipid familes that occurred in all 12 species, but some of the sphingolipid familes were unique to a single species or to groups of species that are living in similar habitats like open or forest area.