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elastic fiber (yellow fiber)

Function: - fibers can stretch up to 1.5 times their length, & snap back to their original length when relaxed Structure: - fibers consisting of elastic fibrils Formation: - formed from the elastic microfibril (consisting of numerous proteins including: - microfibrillar-associated glycoproteins fibrillin, fibullin - elastin receptor - amorphous elastin - the microfibril scaffolds & organizes the deposition of amorphous elastin - amorphous elastin forms from monomers of soluble tropoelastin which is insolubilized & crosslinked into amorphous elastin by lysyl oxidase - lysyl oxidase reacts with specific Lys by oxidative deamination generates reactive aldehydes & allysine - reactive aldehydes and allysines can react with lysine & other allysine residues to crosslink & form desmosine, isodesmosine, & a number of other polyfunctional crosslinks that join surrounding elastin molecules to build an elastin matrix & elastic fiber - crosslinks are responsible for elastin's elasticity. Expression: - found in connective tissue of skin, lungs, arteries, veins, connective tissue proper, elastic cartilage, periodontal ligament, fetal tissue - secreted by fibroblasts & smooth muscle cells in arteries Histology: - elastic fibers stain well with aldehyde fuchsin, orcein, & Weigert's elastic stain in histological sections. - permanganate-bisulfite-toluidine blue reaction is a highly selective & 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, not visible with standard optics. Pathology: - Cutis laxa & Williams syndrome have elastic matrix defects associated with alterations in the elastin gene. - Buschke-Ollendorff syndrome, Menkes disease, pseudoxanthoma elasticum, & Marfan's syndrome have been associated with defects in copper metabolism & lysyl oxidase or defects in the microfibril (defects in fibrillin, or fibullin). - Hurler disease, a lysosomal storage disease, is associated with an altered elastic matrix - hypertension & some congenital heart defects are associated with alterations in the great arteries, arteries, & arterioles with alterations in the elastic matrix.

Related

elastin; tropoelastin (ELN)

General

connective tissue fiber

References

  1. Stedman's Medical Dictionary 27th ed, Williams & Wilkins, Baltimore, 1999
  2. Wikipedia - elastic fiber entry http://en.wikipedia.org/wiki/Elastic_fiber