title: Intracellular biogenesis of collagen fibrils in 'activated fibroblasts' of tendo Achillis. An ultrastructural study in the New Zealand rabbit.
abstract: We have studied the formation of collagen fibrils in 'activated fibroblasts' of tendo Achillis of rabbits. The tendon was in the process of regeneration after experimental partial tenotomy. Samples were taken from the peri-incisional region and analysed by transmission electron microscopy. Ultrastructural examination showed the presence of a 'fine dense granular substance' inside the rough endoplasmic reticulum and procollagen filaments. These come together to form collagen fibrils in the dilated vacuoles of the rough endoplasmic reticulum. The possible intra- and extracellular origin of collagen fibrils is suggested. Within the cell biosynthesis of collagen fibrils take place with the formation of collagen substance which gives rise to procollagen filaments. These make contact in parallel apposition to produce striated 'spindle-shaped bodies' which elongate by the longitudinal attachment of more procollagen filaments and form intracellular nascent collagen fibrils.
authors.affiliation: Department of Morphological Sciences and Surgery, Faculty of Medicine, University of Alcalá de Henares, Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: González Santander
authors.forename: M A
authors.initials: MA
authors.lastname: Plasencia Arriba
authors.forename: G
authors.initials: G
authors.lastname: Martinez Cuadrado
authors.forename: A
authors.initials: A
authors.lastname: Lopez Alonso
authors.forename: M
authors.initials: M
authors.lastname: González-Santander Martinez
authors.forename: F J
authors.initials: FJ
authors.lastname: Martinez Alonso
authors.forename: M
authors.initials: M
authors.lastname: Monteagudo
authors.forename: M V
authors.initials: MV
authors.lastname: Toledo Lobo
mesh_terms: D000125:Achilles Tendon / Q000293:injuries / Q000473:pathology*; D000818:Animals; D003094:Collagen / Q000648:ultrastructure*; D005347:Fibroblasts / Q000473:pathology*; D008297:Male; D020894:Microfibrils / Q000473:pathology*; D008854:Microscopy, Electron; D011347:Procollagen / Q000648:ultrastructure; D011817:Rabbits; D012038:Regeneration / Q000502:physiology; D013708:Tendon Injuries / Q000473:pathology*; D014945:Wound Healing / Q000502:physiology*
chemical_list: D011347:Procollagen; D003094:Collagen