Induction of gastric ornithine decarboxylase in early weaning rats.
OBJECTIVE
Early weaning has been shown to induce intestinal ornithine decarboxylase (ODC) activities and cell proliferation in rats. No information is available about the effect of early weaning on ODC activity in the stomach.


METHODS
Suckling rats were prematurely weaned on postnatal day 15 and followed through day 21. Oxyntic gland mucosa of stomach was obtained on postnatal days 15, 16, 18 and 21 (days 0, 1, 3 and 6 after early weaning) and assayed for ODC activity, DNA, protein and pepsinogen activity. alpha-Difluoromethyl ornithine (DFMO), a specific ODC inhibitor, was given orally to early-weaned pups and its resultant effects were assessed on days 1 and 6 after early weaning.


RESULTS
Stomach mucosal wet weight, DNA, protein and pepsinogen activities significantly increased on day 6 after early weaning. ODC activity increased on days 1, 3, and 6 after early weaning, with the highest increase (3-fold) on day 1 when compared to controls. The increases of ODC activity, DNA and protein contents as induced by early weaning were significantly suppressed when pups were exposed to DFMO. However, no suppression of pepsinogen activity was observed.


CONCLUSIONS
Our study shows that early weaning induces ODC activity and functional growth in the stomach. Gastric ODC activity is essential in gastric mucosal growth processes but not in differentiation. The induction of stomach ODC may act as an early marker in the growth of stomach mucosa induced by early weaning in rats.
Lin
C H
CH
Department of Pediatrics, Wayne State University and Children's Hospital of Michigan, Detroit, Mich., USA. lchuan@med.wayne.edu
Lyons
H
H
Seelbach
M S
MS
Tolia
V
V
Vijesurier
R
R
D000818:Animals; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D000518:Eflornithine / Q000037:antagonists & inhibitors; D004790:Enzyme Induction / Q000187:drug effects* / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005753:Gastric Mucosa / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D023421:Models, Animal; D009955:Ornithine Decarboxylase / Q000096:biosynthesis* / Q000187:drug effects*; D010435:Pepsinogens / Q000096:biosynthesis / Q000187:drug effects; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley / Q000502:physiology*; D013270:Stomach / Q000187:drug effects / Q000254:growth & development; D013997:Time Factors; D014886:Weaning
D004791:Enzyme Inhibitors; D010435:Pepsinogens; D009955:Ornithine Decarboxylase; D000518:Eflornithine