Cell and Tissue Research

, Volume 244, Issue 2, pp 385–394

Lipokeratinocytes of the epidermis of a cetacean (Phocena phocena)

Histochemistry, ultrastructure, and lipid composition

Authors

  • G. K. Menon
    • Department of ZoologyM.S. University
  • S. Grayson
    • Dermatology Service, Veterans Administration Medical CenterUniversity of California School of Medicine
    • Department of DermatologyUniversity of California School of Medicine
  • B. E. Brown
    • Dermatology Service, Veterans Administration Medical CenterUniversity of California School of Medicine
    • Department of DermatologyUniversity of California School of Medicine
  • P. M. Elias
    • Dermatology Service, Veterans Administration Medical CenterUniversity of California School of Medicine
    • Department of DermatologyUniversity of California School of Medicine
Article

DOI: 10.1007/BF00219214

Cite this article as:
Menon, G.K., Grayson, S., Brown, B.E. et al. Cell Tissue Res. (1986) 244: 385. doi:10.1007/BF00219214

Summary

Biochemical and ultrastructural analysis of epidermis from the porpoise, Phocena phocena, revealed certain similarities and differences between cetaceans and terrestrial mammals. The predominant cell of cetacean epidermis, not found in normal terrestrial mammals, is a lipoker-atinocyte, which elaborates not only keratin filaments, but also two types of lipid organelles: first, lamellar bodies, morphologically identical to those of terrestrial mammals, are elaborated in great abundance in all suprabasal epidermal layers, forming intercellular lipid bilayers in the stratum corneum interstices: and second, non-membrane-bounded droplets appear and persist in all epidermal layers. Although the porpoise lipokeratinocyte morpologically resembles the sebokeratocyte of avians in certain respects, nonmembrane-bounded lipid droplets are not released into the intercorneocyte space as they are in avian stratum corneum. Whereas phospholipid/neutral lipid gradients are similar in porpoise and terrestrial mammals, PAS-positive glycoconjugates, specifically glycosphingolipids, are retained in porpoise stratum corneum, but lost from these layers in terrestrials. The novel, non-polar acylglucosyl-ceramides, which also are lost during cornification in terrestrial mammals, are retained in porpoise stratum corneum. The lipid components of porpoise lipokeratinocytes appear to subserve not only barrier function in a hypertonic milieu, but also underlie the unique buoyancy, streamlining, insulatory, and caloric properties exhibited as adaptations to the cetacean habitat.

Key words

Cetaceans Lamellar bodies Epidermal lipids Permeability barrier Electron microscopy Phocena phocena

Copyright information

© Springer-Verlag 1986