DERMAL GROWTH-FACTOR AND TRANSFORMING GROWTH-FACTOR-ALPHA - ROLE IN PROTECTION AND HEALING OF GASTRIC-MUCOSAL LESIONS

The maintenance of the integrity of the gastrointestinal mucosa and th e repair of acute and chronic mucosal lesions are under the influence of various growth factors, especially epidermal growth factor (EGF) an d transforming growth factor-a (TGF-a). EGF originates mainly from sal ivary glands, whereas TGF-a is released locally in the gastric mucosa, particularly when the mucosa is exposed to topical irritants. EGF and TGF-a have similar spectra of biological activity, which include the stimulation of the restitution and proliferation of mucosal cells, gas troprotection, vasodilatation, gastric adaptation to noxious substance s, healing of acute and chronic lesions and inhibition of gastric acid secretion. Accumulation of EGF in the ulcer area as a result of exces sive production by ulcer-associated new cell lineages contributes toge ther with overexpression of EGF receptors in the ulcer area to the mig ration of cells from the ulcer margin and formation of granulation tis sue and microvessels (angiogenesis) during the ulcer healing process.