AJP - Endocrinology and Metabolism, Vol 250, Issue 4 377-E380, Copyright © 1986 by American Physiological Society
Urea concentration and ornithine decarboxylase in liver of female rats
Y. Hitier, O. Champigny and G. Bourdel
In virgin female rats thioacetamide administration (1 mg/100 g body wt)
induced a 16-fold increase in liver ornithine decarboxylase (ODC) activity
and a significant decrease (19%) in hepatic urea concentration. The
ornithine-metabolizing enzymes, ornithine-oxo-acid aminotransferase and
ornithine carbamoyltransferase, were not modified by the treatment; only
carbamoyltransferase, were not modified by the treatment; only
carbamoyl-phosphate synthetase I activity was significantly reduced. In
19-day pregnant rats DL-alpha-difluoromethylornithine treatment inhibited
the expression of enhanced ODC activity occurring normally at this stage of
pregnancy. Concomitantly an inhibition of the usual decrease in hepatic
urea was observed. This increase of ureagenesis occurred without any
increase in liver N-acetylglutamate or ornithine concentrations, which
remained as low as in normal pregnant rats.
