I.c.v. injection of L-ornithine has been shown to have sedative and hypnotic effects on neonatal chicks exposed to acute stressful conditions. To clarify the mechanism, we conducted three experiments under strengthened stressful conditions with corticotropin-releasing factor (CRF). In Experiment 1, the effect of i.c.v. injection of CRF, L-ornithine (0.5 μmol) or CRF with L-ornithine on the stre...

Phaseolotoxin, a tripeptide inhibitor of ornithine transcarbamoylase, is a phytotoxin produced by Pseudomonas syringae pv. phaseolicola, the causal agent of halo-blight in beans. In vivo the toxin is cleaved to release N6-(N'-sulpho-diaminophosphinyl)-Lornithine, the major toxic chemical species present in diseased leaf tissue. This paper reports on the interaction between N8-(N'-sulpho-diamino...

We describe a systematic examination of ornithine decarboxylase activity in 120 colonic mucosal samples which were obtained from 20 subjects without colonic disease to establish the normal mean and standard deviation from proximal to distal colon. Ornithine decarboxylase activity was determined by releasing CO2 from DL-[1-14C]ornithine. The mean ornithine decarboxylase levels (CO2 liberated) ra...

Starvation of the polyamine-dependent Chinese-hamster ovary cells for ornithine or ornithine-derived polyamines in serum-free culture resulted in the formation of cadaverine and its aminopropyl derivatives, N-(3-aminopropyl)cadaverine and NN'-bis(3-aminopropyl)cadaverine. The synthesis of these unusual amines was inhibited by treatment of the cells with DL-2-difluoromethylornithine, a specific ...

In primary cultures of adult rat hepatocytes, the relative rate of ornithine aminotransferase synthesis is increased approximately 7- to 8-fold in response to dibutyryl cyclic AMP. The corresponding increase in ornithine aminotransferase messenger RNA under these conditions was observed to be only 2- to 3-fold. The levels of ornithine aminotransferase mRNA were measured by hybridization of cell...

Assay of ornithine transcarbamylase and carbamyl phosphate synthetase I in submitochondrial fractions of rat liver mitochondria shows they are located primarily in the mitochondrial matrix. Therefore during the urea cycle ornithine must pass from the cytoplasm, where it is formed, to the mitochondrial matrix, where it is carbamylated. The resulting citrulline must then pass from the matrix to t...

Streptococcus lactis metabolizes arginine by the arginine deiminase (ADI) pathway. Resting cells of S. lactis grown in the presence of galactose and arginine maintain a high intracellular ornithine pool in the absence of arginine and other exogenous energy sources. Addition of arginine results in a rapid release of ornithine concomitant with the uptake of arginine. Subsequent arginine metabolis...

BACKGROUND L-Ornithine is a non-protein amino acid with extensive applications in medicine and the food industry. Currently, L-ornithine production is based on microbial fermentation, and few microbes are used for producing L-ornithine owing to unsatisfactory production titer. RESULTS In this study, Corynebacterium glutamicum S9114, a high glutamate-producing strain, was developed for L-ornit...

We have studied the regulation of the expression of ornithine decarboxylase with the aid of transgenic mice harbouring either functional human ornithine decarboxylase genes or the mouse ornithine decarboxylase promoter-driven chloramphenicol acetyltransferase fusion gene in their genome. We used three different stimuli which are well known to enhance ornithine decarboxylase activity in their ap...