Reduction of EGF is associated with the delay of ulcer healing by cigarette smoking.
Cigarette smoking is associated with peptic ulcer diseases. Smokers have lower levels of salivary epidermal growth factor (EGF) than nonsmokers. We investigated whether reduction of EGF is involved in the delay of gastric ulcer healing by cigarette smoking. Rats with acetic acid-induced ulcers were exposed to cigarette smoke (0, 2, or 4% vol/vol) 1 day after ulcer induction. EGF level was elevated 1 day after ulcer induction in salivary glands and serum, and 4 days after ulcer induction in the gastric mucosa. However, cigarette smoke depressed these beneficial effects and EGF mRNA expression in salivary glands and gastric mucosa. Cigarette smoke delayed gastric ulcer healing and reduced cell proliferation, angiogenesis, and mucus synthesis. Exogenous EGF (10 and 20 microg/kg i.v.) before smoke exposure reversed the adverse effects of cigarette smoke, whereas vascular endothelial growth factor level and nitric oxide synthase activity were unaffected. It is concluded that the detrimental effect of cigarette smoke on ulcer healing is a consequence of reduction of angiogenesis, cell proliferation, and mucus secretion through the depressive action on EGF biosynthesis and its mRNA expression in salivary glands and gastric mucosa.
Ma
L
L
Department of Pharmacology, Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
Wang
W P
WP
Chow
J Y
JY
Yuen
S T
ST
Cho
C H
CH
D000818:Animals; D016228:Endothelial Growth Factors / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000097:blood / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D005753:Gastric Mucosa / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D008222:Lymphokines / Q000378:metabolism; D008297:Male; D009093:Mucus / Q000187:drug effects / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000187:drug effects; D019001:Nitric Oxide Synthase / Q000378:metabolism; D010084:Oxidation-Reduction; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012469:Salivary Glands / Q000378:metabolism; D012907:Smoking / Q000009:adverse effects*; D013276:Stomach Ulcer / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D014945:Wound Healing / Q000502:physiology*
D016228:Endothelial Growth Factors; D008222:Lymphokines; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D004815:Epidermal Growth Factor; D019001:Nitric Oxide Synthase