EFFECT OF EPIDERMAL GROWTH-FACTOR ON THE DEVELOPMENT OF RAT GASTRIC-MUCOSA

Epidermal growth factor (EGF) was shown to stimulate the growth of adult rat gastric mucosa and to increase DNA synthesis of mouse small and large intestinal mucosa. Whether EGF affects the functional and structural development of the rat gastric mucosa was examined. Rats were injected with 20 .mu.g/kg EGF 3 times/day for 5 days beginning on the 10th day after birth. A control group of animals received saline injections of identical volume. All rats were killed on day 15. EGF significantly increased the weight of the whole stomach and the DNA, RNA and protein content of the oxyntic gland mucosa, but had no effect on the RNA/DNA ratio, or antral and serum gastrin levels. Two groups of similarly treated rats were anesthetized with ether, pylorus-ligated and injected with saline or pentagastrin (250 .mu.g/kg) after they had recovered from anesthesia. EGF-treated rats had significantly higher rates of basal acid secretion and pentagastrin-stimulated acid secretion than the saline-treated controls. EGF did not alter basal or pentagastrin-stimulated pepsin secretion nor did it change mucosal pepsinogen content. Apparently, EGF stimulates oxyntic mucosal growth in unweaned rats, but it does not lead to precocious maturation or functional development.