Role of ornithine decarboxylase in functional development of rat gastric mucosa.

The effects of inhibiting polyamine synthesis on the functional development of the gastric mucosa were studied in rats from 5 to 40 days old. They were treated from day 14 after birth with alpha-difluoromethylornithine (DFMO) at a concentration of 2% in the drinking water of mothers and pups. The rats were weaned on day 18. Basal acid and pepsin secretion, oxyntic gland mucosal pepsinogen content, and antral gastrin content followed similar developmental patterns in control animals. Levels of these parameters remained measurable but low until around the time of weaning, when dramatic log linear rises were observed. DFMO failed to delay the onset of the rises in any of these maturational indices. Ornithine decarboxylase (ODC) activity in the oxyntic gland mucosa was low but discernible in rats of every age studied. DFMO significantly reduced ODC activity at every age except 40 days, where there was no difference from control values. Our results suggest that ODC activity in the rat gastric mucosa does not change appreciably during neonatal development and that inhibiting putrescine synthesis from its precursor ornithine by DFMO treatment does not prevent or delay gastric mucosal maturation.