Pathology of inflammatory-reparative response in punched wounds of the chicken skin

Vascular and cellular responses were examined sequentially in punched wounds of the chicken skin. The 'dye' and the 'colloidal carbon' technique revealed that the increased permeability response was immediate and sustained. The response attained its peak at 1 hour and persisted for up to 6 hours, but the increased permeability was prolonged over a period of 48 h. The increase in vascular permeability at all stages was confined to venules and small veins only. In the later stages of healing, the newly formed vessels in the granulation tissue were leaky. The initial migration of leukocytes comprised heterophils and monocytoid cells. This was soon followed by infiltration of some basophils. A striking feature of the reaction, in the granulation tissue, was that the monocytoid cells apparently coalesced, formed syncytia, and even what appeared to be distinct multinucleated giant cells. Whereas mast cells participated in the early stages, they were absent in the granulation tissue. Proliferation of the fibroblasts began around 18 h, angiogenesis and re-epithelialization at 3 days, and the healing was complete by about 7 days.