Granulation Tissue as a Contractile Organ

Abstract

Contracting granulation tissues contain fibroblasts that develop characteristics typical of smooth muscle: (a) They contain an extensive cytoplasmic fibrillar system. (b) They show immunofluorescent labeling of their cytoplasm with human anti-smooth muscle serum. (c) The nuclei show complicated folds and indentations, indicative of cellular contraction. (d) There are cell-to-cell and cell-to-stroma attachments. (e) It is possible to extract similar quantities of actomyosin (having the same adenosine triphosphatase activity) from granulation tissue and from pregnant rat uterus. (f) Strips of granulation tissue, when tested pharmacologically in vitro, behave similarly to smooth muscle. All these data support the view that, under certain conditions, fibroblasts can differentiate into a cell type structurally and functionally similar to smooth muscle and that this cell, the "myo-fibroblast," plays an important role in connective tissue contraction.

Aspectos celulares da cicatrização

“…Ocorre, concomitantemente, reorganização da matriz extracelular, que se transforma de provisória em definitiva, cuja intensidade fenotípica, observada nas cicatrizes, reflete a intensidade dos fenômenos que ocorreram, bem como o grau de equilíbrio ou desequilíbrio entre eles. 32 Com o decorrer do processo de maturação e remodelagem, a maioria dos vasos, fibroblastos e célu-las inflamatórias desaparece do local da ferida mediante processos de emigração, apoptose ou outros mecanismos desconhecidos de morte celular. Esse fato leva à formação de cicatriz com reduzido número de células.…”

Localization of [alpha]-actinin and tropomyosin in muscle and nonmuscle systems

“…While investigating the mechanisms involved in wound contraction, it was found that granulation tissue fibroblasts progressively develop several features typical of smooth muscle cells (Gabbiani et al, 1972).…”

Management of contractures: A five-year experience at Komfo Anokye Teaching Hospital in Kumasi

“…6,7 The process is due to the action of the myofibroblast -a cell with fibroblast and smooth muscle characteristics distributed throughout granulation tissue present in wounds. 8 Contraction of myofibroblasts shrink the wound. This is followed by collagen deposition and cross-linking to maintain contraction.…”

“…7 It is also known that contraction of the palmar fascia and surrounding structures in Dupuytren's contracture is directly related to the contractile properties of myofibroblasts. 8 In embryogenesis, failure of differentiation of the digits leads to scar tissue formation, which flexes the proximal inter-phalangeal joints with resulting camptodactyly. 5 Contractures can cause significant functional and/or cosmetic problems to patients.…”

“…14 Other authors are interested in contractures of a particular aetiology such as burns, 12,15 trauma, 3 Buruli ulcer, 4 cancrum oris 16 or Dupuytren's contracture. 6,8 The current study was undertaken to document the spectrum and management of patients with contractures of various types and aetiologies presenting to the author at the Plastic and Reconstructive Surgery Unit of Komfo Anokye Teaching Hospital in Kumasi.…”