TY - JOUR
T1 - Lipids of the stratum corneum vary with cutaneous water loss among larks along a temperature-moisture gradient
AU - Haugen, M.
AU - Williams, J.B.
AU - Wertz, P.
AU - Tieleman, B.I.
PY - 2003
Y1 - 2003
N2 - We explored the relationship between lipids of the stratum corneum (SC), the barrier to water-vapor diffusion of the skin, and cutaneous water loss (CWL) of species of free-living larks along a temperature-moisture gradient. Our results showed that free fatty acids, cholesterol, and ceramides were the major constituents of SC in larks from different environments including the Netherlands, a mesic environment; Iran, a semiarid region; and several areas in Saudi Arabia, a hot dry desert. We found that CWL was reduced among larks inhabiting deserts, but our data did not support the hypothesis that birds from desert environments have larger quantities of lipids per unit dry mass of the SC than larks from more mesic environments. Instead, larks in arid environments had a higher proportion of ceramides, especially the more polar fractions 4 - 6, and a smaller proportion of free fatty acids in their SC, an adjustment that apparently reduced their CWL. Subtle changes in the ratios of lipid classes can apparently alter the movement of water vapor through the skin. We hypothesize that desert birds have higher proportions of ceramides in their SC and lower proportions of free fatty acids because this combination allows the lipid lamellae to exist in a more highly ordered crystalline phase and consequently creates a tighter barrier to water-vapor diffusion.
AB - We explored the relationship between lipids of the stratum corneum (SC), the barrier to water-vapor diffusion of the skin, and cutaneous water loss (CWL) of species of free-living larks along a temperature-moisture gradient. Our results showed that free fatty acids, cholesterol, and ceramides were the major constituents of SC in larks from different environments including the Netherlands, a mesic environment; Iran, a semiarid region; and several areas in Saudi Arabia, a hot dry desert. We found that CWL was reduced among larks inhabiting deserts, but our data did not support the hypothesis that birds from desert environments have larger quantities of lipids per unit dry mass of the SC than larks from more mesic environments. Instead, larks in arid environments had a higher proportion of ceramides, especially the more polar fractions 4 - 6, and a smaller proportion of free fatty acids in their SC, an adjustment that apparently reduced their CWL. Subtle changes in the ratios of lipid classes can apparently alter the movement of water vapor through the skin. We hypothesize that desert birds have higher proportions of ceramides in their SC and lower proportions of free fatty acids because this combination allows the lipid lamellae to exist in a more highly ordered crystalline phase and consequently creates a tighter barrier to water-vapor diffusion.
KW - AVIAN EPIDERMAL DIFFERENTIATION
KW - THIN-LAYER-CHROMATOGRAPHY
KW - PERMEABILITY BARRIER
KW - PENETRATION ENHANCEMENT
KW - MASS-SPECTROMETRY
KW - COLUMBA-LIVIA
KW - SKIN
KW - CERAMIDES
KW - BIRDS
KW - QUANTITATION
U2 - 10.1086/380213
DO - 10.1086/380213
M3 - Article
C2 - 14988806
SN - 1522-2152
VL - 76
SP - 907
EP - 917
JO - Physiological and Biochemical Zoology
JF - Physiological and Biochemical Zoology
IS - 6
ER -