The cell proliferation of the gastric epithelium is stimulated by food depr
ivation in suckling rats, and LHRH inhibits this process as it does in othe
r hyperproliferating tissues. However, as LHRH antagonist is also being use
d as a potent antiproliferative agent for tumors, this study aims to invest
igate whether it plays any role on the cell proliferation of the gastric ep
ithelium. Seventeen-day-old rats were fasted for 20 h and treated with LHRH
antagonist, LHRH, or both during this period. The following morning, anima
ls were injected with BrDU to label proliferating cells, and were sacrifice
d 1 h later. Paraffin sections of the gastric mucosa were processed for imm
unohistochemistry and BrDU labeled and non-labeled epithelial cells were co
unted to determine the labeling index (LI). None of the hormone treatments
changed body weight or the morphology of the stomach. Apoptotic cells were
observed in the gastric gland in treated rats. The LI were inhibited by the
antagonist, LHRH or both, showing that the LHRH antagonist plays an inhibi
tory role on the hyperproliferating gastric epithelium. These results sugge
st that both LHRH agonist and antagonist can influence the proliferative ac
tivity in suckling rats, though the mode of action remains to be determined
. (C) 1999 Elsevier Science B.V. All rights reserved.