THE METABOLISM OF dl-TRYPTOPHAN-3a,7a,7-C14 AND dl-TRYPTOPHAN-α-C14 IN THE RAT

Stimulation of C14-melatonin synthesis from C14-tryptophan by noradrenaline in rat pineal in organ culture.

Previous work has shown that the activity of the melatonin-forming enzyme in the rat pineal gland is elevated in rats kept in continuous darkness as compared to those kept in continuous light. Information about environmental lighting reaches the pineal gland via nerves that liberate noradrenaline. Rat pineal glands in organ culture can form C(14)-melatonin from C(14)-tryptophan as follows: tryp...

The effect of iproniazid on the metabolism of dl-epinephrine-2-C14 in the human.

8202 The effect of iproniazid on the metabolism of dl-epinephrine-2-C14 in the human. N. Kirshner, NcC. Goodall, L. Rosen. 1 8203 Substrate requirements for the positive inotropic action of arsenate on electrically-stimulated rat ventricle strips. J. N. Covin, D. A. Berman. 8 8204 Oxidation of glucose-l-C14, glucose-6-Cl4 and pyruvate-2-C14 by contracting rat ventricle strips in the presence an...

The metabolism of ascorbic acid-1-C14 and oxalic acid-C14 in the rat.

It is known that oxalic acid is a product of ascorbic acid metabolism in the guinea pig (1) and rat (2), and is formed in man from unidentified precursors (3). Oxalates are also of interest because of their occasional toxicity and unexplained deposition. Ascorbic, dehydroascorbic, and 2,3diketogulonic acids are known to give rise to oxalic and threonic acids in approximately quantitative yields...

Quantitative DL-tryptophan requirement of the weanling pig.

Induction by L-tryptophan and an analogue, alpha-methyl-DL-tryptophan, of the enzymes catabolizing L-tryptophan in Pseudomonas.

An investigation was made of the pattern of induction of the enzymes that metabolize l-tryptophan through kynurenic acid (the quinoline pathway) in Pseudomonas fluorescens. The first four enzymes in the pathway were not induced in the same proportions or in the same time courses. This lack of coordinate induction excludes a mechanism of regulation of these enzymes at a single site as proposed i...