Intracellular biogenesis of collagen fibrils in 'activated fibroblasts' of tendo Achillis. An ultrastructural study in the New Zealand rabbit.
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.
González Santander
R
R
Department of Morphological Sciences and Surgery, Faculty of Medicine, University of Alcalá de Henares, Madrid, Spain.
Plasencia Arriba
M A
MA
Martinez Cuadrado
G
G
Lopez Alonso
A
A
González-Santander Martinez
M
M
Martinez Alonso
F J
FJ
Monteagudo
M
M
Toledo Lobo
M V
MV
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*
D011347:Procollagen; D003094:Collagen