ISSN:
1432-0878
Keywords:
Ciliary epithelium
;
Orthogonal arrays of particles
;
Filipin
;
Freeze-fracture
;
Electron microscopy
;
Rat
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary It has been suggested that orthogonal arrays of particles may increase the rigidity of plasma membrane, as does cholesterol. Therefore, using freeze-fractured non- pigmented ciliary epithelium, the distribution of such arrays was compared to the distribution of membrane deformations induced by the sterol-probes filipin and digitonin in different domains of the basolateral plasma membrane. The distribution of orthogonal arrays of particles was homogeneous between different regions of the basolateral membrane of the non-pigmented ciliary epithelium, while the number of filipin-induced alterations was nearly 4 times higher in the membrane domains not in contact with the basal lamina than in domains in contact with it. Contrary to the homogeneous distribution of arrays, digitonin-induced deformations also differed markedly in these two basolateral membrane domains. Considering that a marked positive response to sterol probes implies a high sterol content, we conclude that orthogonal arrays of particles can occur in plasma membrane regions well-provided with cholesterol and not in direct contact with the basal lamina. Other possible roles of these arrays are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00213838
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