Myofibroblasts in cotton-induced granulation tissue and the bovine adrenal capsule: morphological aspects.

Ultrastructural studies of one week old cotton-induced granulation tissue revealed the presence of polymorphonuclear neutrophils (PMN), macrophages and mast cells, whilst the granulation tissue from two week old cotton implants contained fibroblasts, myofibroblasts and abundant collagen fibres. Similarly, the bovine adrenal capsule contained both fibroblasts and myofibroblasts. It is proposed that the bovine adrenal capsule and two week cotton-induced granulation tissue could be utilized as in-vitro models to study the mechanism(s) involved in myofibroblast contraction.