[The effect of ACTH and several antimetabolites of vitamin B6 on the activity of tyrosine aminotransferase in the liver of intact and hypophysectomized rats]

Abstract

ACTH injected intraperitoneally in a dose of 140 Units per 1 kg of body weight to intact rats or to rats subjected to hypophysectomy 24 hours before the experiment produced an increase in the activity of tyrosine-aminotrasferase in the liver (4.5 or 2.5 times, respectively) in comparison with the normal. D-cycloserine and its dimere injected intraperitoneally to the intact starving rats in a dose of 2.0-2.5 g per 1 kg of body weight produced in 4 hours a sharp elevation in the liver of the activity of tyrosine-amino transferase, whose induction constituted 75 and 180%, respectively. 24 hours after hypophysectomy D-cycloserine produced no induction of this enzyme in the rat liver; in difference from this, the D-cycloserine dimere produced an induced formation of tyrosine-aminotransferase (comparable with ACTH) in the liver of hypophysectomized rats. This indicated that the induction mechanism of tyrosine-aminotransferase in the liver of rats under the effect of D-cycloserine and its dimere differed.