Catfish gel extract causes increase in vascular permeability in the rat skin

Catfish from the Arabian Gulf (Arius bilineatus, Valenciennes) secrete a proteinaceous gel through the epidermis when threatened or injured; a preparation from this gel has been shown to stimulate wound healing. In this report, we wish to present evidence that the aqueous component of the gel potently stimulates vascular permeability when injected intradermally in rat skin, as measured by Evans blue leakage from plasma. This effect is dose dependent (0.06-1.2 μg protein), abolished by boiling the gel for 5 min and, at low doses, increased by co-administration of bradykinin (50 ng). Histopathological examination of the skin within the time course of the experiment (30 min) revealed significant edema with neutrophilic perivascular panniculitis which showed considerable reversibility within 3 h. These results indicate that the catfish gel may facilitate the wound healing process through its action on capillaries and the associated release of neutrophils amongst other wound healing activities.