Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: CAS:1069-31-4 (ornithine)
 6,755 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To enable further structure-activity comparisons among radioprotective phosphorothioates, S-2,omega-diaminoalkyl dihydrogen phosphorothioates were synthesized from L-2,4-diaminobutyric acid, L-ornithine, L-lysine, and DL-2,7-diaminoheptanoic acid as homologues of S-2,3-diaminopropyl dihydrogen phosphorothioate (4) and as isomeric analogues of S-2-[(omega-aminoalkyl)amino]ethyl dihydrogen phosphorothioates (e.g., 1). The preferred route that evolved from exploratory trials retained optical activity and involved the reduction of methyl 2,omega-bis(benzoylamino)alkanoates with lithium borohydride, debenzoylation-bromodehydroxylation, and reaction of the resulting 1-(bromomethyl)-1,omega-alkanediamine dihydrobromides with trisodium phosphorothioate. The products of an alternative route that involved the reduction of phthaloylated intermediates with sodium borohydride were racemic. Exploratory conversions of N-(omega-alkenyl)phthalimides failed to provide suitable precursors of the target compounds. In terms of a protective index, these homologues were significantly more radioprotective than the parent phosphorothioate 4 when administered intraperitoneally to mice prior to whole-body gamma irradiation. The homologues derived from L-lysine also showed good peroral activity. No apparent difference was observed in the protection afforded by optically active homologues and the corresponding racemates.
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PMID:S-2,omega-Diaminoalkyl dihydrogen phosphorothioates as antiradiation agents. 45 19

Amino acid levels have been determined in plasma and in four cerebral regions of rats one month after portocaval shunt. Many plasma amino acids are significantly lowered (asparagine, glutamine, theonine, serine, alanine, valine, leucine, isoleucine, cystine, lysine), while others remain unchanged (taurine, glycine, proline, tryptophan, ornithine, histidine, arginine). Asparagine and glutamine levels are significantly higher than in normal rats, and a net increase of tyrosine (100%), phenylalanine (50%) and citrulline (50%) is evident. In the shunted rat brain the most prominent feature is a very large rise (up to fivefold) of tyrosine, phenylalanine, histidine, citrulline, tryptophan, and glutamine uniformly in the tested regions. Other neutral amino acids are slightly increased. Lysine and arginine are decreased in cerebellum and pons-medulla; taurine, in forebrain and cerebellum. Cerebral permeability to L-amino acids was studied in vivo. Neutral amino acid permeability is greatly increased, whereas basic amino acids show a net decrease in their rate of passage from blood to the brain. No changes are observed for GABA and glutamic acid. These data suggest an altered permeability of the cerebral capillary membranes, which seems to be selective for the different amino acid transport classes. Competitive inhibition experiments demonstrated that the increased brain permeability to neutral amino acids after portocaval shunt is due to an enhancement of the saturable transport. The sharp rise in the brain of some essential neutral amino acids (phenylalanine, tyrosine, trytophan, histidine), largely exceeding their changes in plasma, and the slight cerebral increase of other neutral amino acids despite their lowered level and the rise of competing amino acids in the plasma, is consistent with our observation of enhanced transport for the neutral class. In hepatic encephalopathy, correction of the altered plasma amino acid levels has been reported to improve the clinical status. If this result is connected to the concomitant correction of the brain amino acid levels, carefully selected competitive inhibition among various plasma amino acids could be a useful therapeutic tool in this pathologic condition. However, the increased activity of the neutral amino acid transport system adds a new factor to the problem, since it probably implies that the competing amino acids will accumulate to unphysiological levels in the brain.
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PMID:Cerebral amino acid levels and uptake in rats after portocaval anastomosis: II. Regional studies in vivo. 46 65

The effects of several types of vasopressin analogs that are considered to be resistant to some of the physiologically significant enzymatic systems were investigated utilizing rats trained in a passive avoidance task. Enhancement of avoidance latencies was observed 2, 7 and 13 days after the single learning trial when deamino-carbavasopressins, triglycyl-8-lysine-vasopressin or its des-glycinamide derivative, and deamino-D-arginine-vasopressin were given shortly after the learning trial in the dose of 1 microgram s.c. (8-L-Arginine)deamino-6-carba-vasopressin and (8-L-ornithine)deamino-6-carba-vasopressin were also active in the dose of 0.1 microgram. Lysine vasopressin and its des-glycinamide derivative failed to enhance avoidance latencies in part of the experiments if doses of 0.3--3 micrograms were administered and 7 or 13 day intervals were used between the learning and the test trials. Enhancement of avoidance latencies was also observed, if some of the peptides were injected 20 min but not 120 or 180 min before the test trial. Marked depression of exploratory behavior of rats in an open field was found after s.c. injections of low doses (1--3 micrograms kg-1) of deamino-carba-vasopressins. Higher doses (10--30 micrograms kg-1) induced sleep-like immobility not accompanied by ataxia or catalepsy.
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PMID:Vasopressin analogs: sedative properties and passive avoidance behavior in rats. 47 29

A new method for measuring transintegumental uptake in living schistosomes in vitro has been applied to the study of individual males and females. Uptake of a 14-C labeled test metabolite was compared to that of tritiated water (a highly diffusible reference substance). Use of the short half-life (T 1/2 = 100 min) isotope 113m-Indium, bound to EDTA (ethylene diamine tetra-acetic acid, a nondiffusible reference substance) permitted quantification of the relative amount of 14-C test substance passively adhering to the schistosoma surface. Substraction of this amount provided an estimate of net uptake. D-glucose uptake, as measured by this method, increased with time, approaching equilibrium by two min; a positive correlation between temperature and glucose uptake was also observed. Nondialyzable components in rat, human, horse and fetal calf sera did not enhance glucose uptake. In both male and female schistosomes, minimal uptakes were seen for the nonmetabolizable sugar alcohol mannitol (MW = 182). L-glucose uptake was similarly low, but high uptakes were observed in both sexes for D-glucose. In addition to confirming the stereospecificity of hexose uptake, these studies suggested our technique provides a sensitive method for measurement of both high and low uptake compounds. The uptakes of D-glucose and the L-amino acids--arginine, ornithine, lysine, histidine, phenylalanine and serine--were comparatively higher in female than male schistosomes. Slight elevations in uptake by females were observed for threonine, valine and glycine, but aspartate uptake was slightly higher in males. No dramatic male-female differences were immediately apparent for the uptakes of proline, leucine, isoleucine, tyrosine and glutamate. Schistosomal uptake of L-amino acids that are essential for vertebrates was generally higher than uptake of the nonessential amino acids.
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PMID:Transintegumental uptake of metabolic substrates in male and female Schistosoma mansoni. 48 63

The possibility that arginine and lysine might be decarboxylated by rat tissues was investigated. No evidence for decarboxylation of arginine could be found. Lysine decarbosylase (L-lysine carboxy-lyase, EC 4.1.1.18) activity producing CO2 and cadaverine was detected in extracts from rat ventral prostate, androgen-stimulated mouse kidney, regenerating rat liver and livers from rats pretreated with thioacetamide. These tissues all have high ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) activities. Lysine and ornithine decarboxylase activities were lost to similar extents on inhibition of protein synthesis by cycloheximide and on exposure to alpha-difluoromethylornithine. A highly purified ornithine decarboxylase preparation was able to decarboxylate lysine and the ratio of ornithine to lysine decarboxylase activities was constant throughout purification. Kinetic studies of the purified preparation showed that the V for ornithine was about 4-fold greater than for lysine, but the Km for lysine (9 mM) was 100-times greater than that for ornithine (0.09 mM). These experiments indicate that all of the detectable lysine decarboxylase activity in rat and mouse tissues was due to the action of ornithine decarboxylase and that significant cadaverine production in vivo would occur only when ornithine decarboxylase activity is high and lysine concentrations substantially exceed those of ornithine.
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PMID:Decarboxylation of ornithine and lysine in rat tissues. 48 92

Three patients with the rare hyperornithinemia with gyrate atrophy of the choroid and retina (HOGA) syndrome were studied to elucidate the metabolic derangement and its pathologic concomitants. Tenfold elevations of blood ornithine levels, decreases in lysine levels, and hitherto unreported decreases in blood glutamate and glutamine concentration were observed. The output of ornithine from muscle kidney and splanchnic beds was curtailed or reversed after intravenous glucose. Levels of ornithine in venous blood declined after oral glucose, and rose after intravenous arginine. Increased amounts of 3-amino-2-piperidone were found in the urine, but these did not increase after the arginine-induced increase in ornithine levels. Liver biopsies in two patients revealed a marked alteration in mitochondrial ultrastructure. These studies extend the knowledge of the metabolic and pathologic derangements in HOGA. These findings are consistent with a disorder of ornithine-ketoacid transaminase, but such a disorder might not account for all the observations.
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PMID:Amino-acid metabolism and liver ultrastructure in hyperornithinemia with gyrate atrophy of the choroid and retina. 49 62

Synaptosomes isolated from adult or newborn rat cerebrum take up L-lysine by two saturable systems, one with a high affinity low capacity and the other with a low affinity high capacity. Initial rate of uptake for low lysine concentrations is mort tissue. Analysis of kinetic data indicates that synaptosomes of the newborn have a higher Vmax than those of the adult for high affinity system but adult for high affinity system but adult synaptosomes have a higher Vmax than newborn for low affinity system. At a physiological lysine concentration of 0.5 mM, the calculated contributions of two systems indicate that the adult uptake occurs for about 71% by low affinity system but the newborn utilizes both systems to the same extent. The uptake is sodium independent but pH dependent. Lysine uptake is inhibited by other dibasic amino acids, arginine and ornithine but not cystine. Kinetic analysis indicates that arginine specifically inhibits the high affinity, low Km system for lysine uptake.
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PMID:Developmental and other characteristics of lysine uptake by rat brain synaptosomes. 49 92

The free amino acids in eccrine sweat collected from the forearms of 20 healthy trained and 20 healthy untrained men during controlled exercise were determined quantitatively using ion exchange column chromatography. Sweat was deproteinized by adding an equal volume of 5% sulphosalicylic acid. The amino acid concentrations showed a constant qualitative pattern in sweat and large individual differences. Essential amino acids, such as isoleucine, leucine, lysine, methionine, phenylalanine, and valine were excreted in relatively small amounts. As compared to the trained men, untrained men showed statistically significantly higher concentrations in sweat for the following amino acids: Alanine, arginine, glycine, histidine, isoleucine, leucine, lysine, ornithine, phenylalanine, serine, taurine, threonine, tyrosine, and valine. No significant differences were found for citrulline, cystine, ethanolamine, and methionine. The comparison of the amino acid excretions in sweat obtained under controlled exercise and in urine showed that the amounts of amino acids excreted in sweat under controlled exercise were comparable to the losses of amino acids in urine.
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PMID:Quantitative study of free amino acids in human eccrine sweat excreted from the forearms of healthy trained and untrained men during exercise. 53 94

The polyamide layer technique for the chromatographic separation of dimethylaminonaphthalene sulphonyl amino acids has been adapted to the qualitative analysis of amino acids in media before and after the growth of micro-organisms. The method has been used to study the amino acids metabolized by cultures of proteolytic clostridia growing in a medium consisting of an acid hydrolysate of casein as a source of amino acids and small amounts of yeast extract and trypticase as sources of growth factors. The chromatograms of the media after growth showed which amino acids were used and which new amino acids were produced. Clostridium botulinum type F (proteolytic), C. ghoni, C. mangenoti and C. putrificum were found to reduce proline to 5-aminovaleric acid and to produce 2-aminobutyric acid, properties they shared with C. sporogenes and C. sticklandii. C. botulinum type G and C. subterminale used glycine, lysine, serine, and arginine but in contrast to C. sticklandii they neither reduced proline to 5-aminovaleric acid nor produced 2-aminobutyric acid. Both organisms oxidized phenylalanine, tyrosine and tryptophan to phenylacetic acid, p-hydroxyphenyl acetic acid and indole acetic acid respectively. C. lituseburense and C. scatologenes used serine, threonine and arginine and produced 2-amino butyric acid and ornithine. C. lentoputrescens, C. limosum and C. malenomenatum resembled C. tetanomorphum by using glutamic acid and tyrosine. The chromatograms always showed the physiological group to which an organism belonged and in some cases were characteristic of the species.
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PMID:Amino acid utilization patterns in clostridial taxonomy. 53 67

Previous work has established that macrophages in culture release sulphate from heparin. We now report that increased uptake and desulphation of heparin occurred in the presence of polycations (poly-L-ornithine and poly-DL-lysine) and that the increase in heparin uptake was by about 30-fold. The desulphation was less related to uptake than to the nature of the bound polycation. Serum was found to have an inhibitory effect on heparin uptake while polycations inhibited heparin desulphation by macrophage extracts.
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PMID:Differential effect of polycations on uptake and desulphation of heparin. 54 23


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