Elastic fiber
Subcutaneous tissue from a young rabbit. Highly magnified. (Elastic fibers labeled at right. )
Gray's	subject #104 377

Elastic fibers (or yellow fibers) are bundles of proteins (elastin) found in extracellular matrix^[1] of connective tissue and produced by fibroblasts and smooth muscle cells in arteries. These fibers can stretch up to 1.5 times their length, and snap back to their original length when relaxed. Elastic fibers include elastin, elaunin and oxytalan.

Elastic tissue is classified as "connective tissue proper".^[2]

The elastic fiber is formed from the elastic microfibril (consisting of numerous proteins such as microfibrillar-associated glycoproteins, fibrillin, fibullin, and the elastin receptor) and amorphous elastin.

The microfibril scaffolds and organizes the deposition of amorphous elastin. Amorphous elastin forms from monomers of soluble tropoelastin which is insolubilized and crosslinked into amorphous elastin by lysyl oxidase. Lysyl oxidase reacts with specific lysine residues and by oxidative deamination generates reactive aldehydes and allysine.

These reactive aldehydes and allysines can react with lysine and other allysine residues to crosslink and form desmosine, isodesmosine, and a number of other polyfunctional crosslinks that join surrounding elastin molecules to build an elastin matrix and elastic fiber. These unique crosslinks are responsible for elastin's elasticity.

Contents 1 Distribution 2 Histology 3 Defects and disease 4 See also 5 References 6 External links

[edit] Distribution

Elastic fibers are found in the skin, lungs, arteries, veins, connective tissue proper, elastic cartilage, periodontal ligament, fetal tissue and other structures.

[edit] Histology

Elastic fibers stain well with aldehyde fuchsin, orcein,^[3] and Weigert's elastic stain in histological sections.

The permanganate-bisulfite-toluidine blue reaction is a highly selective and sensitive method for demonstrating elastic fibers under polarizing optics. The induced birefringence demonstrates the highly ordered molecular structure of the elastin molecules in the elastic fiber. This is not readily apparent under normal optics.

[edit] Defects and disease

There is evidence to believe that certain defects of any components of the elastic matrix may impair and alter the structural appearance of elastic and collagen fibers.

Cutis laxa and Williams syndrome have elastic matrix defects that have been directly associated with alterations in the elastin gene.

Buschke-Ollendorff syndrome, Menkes disease, pseudoxanthoma elasticum, and Marfan's syndrome have been associated with defects in copper metabolism and lysyl oxidase or defects in the microfibril (defects in fibrillin, or fibullin for example).

Hurler disease, a lysosomal storage disease, is associated with an altered elastic matrix.

Hypertension and some congenital heart defects are associated with alterations in the great arteries, arteries, and arterioles with alterations in the elastic matrix.

[edit] See also

• Elastic artery

[edit] References

[edit] External links

• Histology at BU 00801ooa - "Connective Tissue elastic fibers "
• UIUC Histology Subject 328
• Elastic+fibers at eMedicine Dictionary
• Organology at UC Davis TermsCells&Tissues/connective/elastic/elastic2 - "Connective tissue, elastic (LM, High)"

v • d • e Histology: connective tissue Classification Proper/ Fibrous Loose Areolar · Reticular non-fibrous: Adipose (Brown, White) Dense Dense irregular connective tissue (Submucosa, Dermis) · Dense regular connective tissue (Ligament, Tendon, Aponeurosis) Embryonic Mucous · Mesenchymal Specialized Cartilage · Bone · Blood Composition Extracellular matrix (noncellular) Ground substance Tissue fluid Fibers Reticular fibers: Collagen Elastic fibers: Fibrillin (FBN1, FBN2, FBN3) Cells Resident Fibroblast · Reticular cell · Tendon cell Adipocyte Chondroblast · Osteoblast Wandering cell Mast cell · Macrophage see also soft tissue integument, SF, LCT navs: anat/physio, noncongen/congen/neoplasia, symptoms+signs/eponymous, proc muscle, DF+DRCT navs: anat/hist/physio, acquired myopathy/congenital myopathy/neoplasia, symptoms+signs/eponymous, proc

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