The effect of epidermal growth factor on wound healing in mice

The data presented in this paper focus attention on the possible evolutionary advantages of communal licking, based upon the delivery of wound healing factors in the saliva to an immediate local injury. It is suggested that epidermal growth factor (EGF) is one of these factors, as topical application of EGF to a standardized back wound in mice caged separately enhanced wound closure in both control and sialectomized animals. A sex difference in the wound closing response was evident from these studies. The testosterone dependence of EGF synthesis and its action on wound closure as well as its release upon α-adrenergic stimulation, make teleological sense, in a context of an acute response to injury caused by fighting. It is also suggested that prostaglandins released in injured tissue may modulate these acute effects of EGF, as prostaglandin inhibitors prevented EGF-induced closure. Since EGF is known to be a potent mitogen for murine fibroblast and epithelial cell lines, it may also participate in longer term effects integral to wound healing.