• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.75-84
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• 1995

Acid secretion and NO synthase activity were determined in isolated gastric glands following hypoxia/reoxygenation and acidosis to investigate the involvement of NO in acid secretion. Isolated gastric glands were exposed to hypoxia (30 min)/reoxygenation (1 h) and/or to acidosis (pH 6.0 and 4.0). Acid secretion was measured by the ratio of $[^{14}C]-aminopyrine$ accumulation between intra- and extraglands. NO synthase activity was determined by percent conversion to $[^{14}C]-citrulline\;from\;[^{14}C]L-arginine$, a precursor of NO. The results indicate that dibutyryl cAMP stimulated acid secretion dose-dependently but had no effect on NO synthase activity in basal gastric glands. Hypoxia/reoxygenation significantly suppressed acid secretion both in unstimulated and stimulated gastric glands, which was exaggerated by acidosis. Constitutive NO synthase, activity, not responded to dibutyryl cAMP, was also inhibited by hypoxia/reoxygenation and acidosis. In conclusion, pathologic state of gastric mucosa such as hypoxia/reoxygenation and acidosis suppresses both acid secretion and NO release but the role of NO in acid secretion stimulated by dibutyryl cAMP in basal gastric glands is not significant.

• BMB Reports
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• v.39 no.4
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• pp.400-405
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• 2006

A 16-month old boy was referred to our hospital for evaluation of recurrent generalized tonic clonic seizures. Metabolic evaluation revealed significant hyperammonemia ($1,112\;{\mu}g/dl$). Amino acid/acylcarnitine screening using tandem mass spectrometry showed markedly increased plasma levels of citrulline ($1,350\;{\mu}M/l$) with undetectable levels of arginine and arginosuccinic acid. Urinary excretion of citrulline was markedly increased ($38,617\;{\mu}M/g$ creatinine). Brain MRI findings showed diffuse high-signal intensity lesions, that involved gray and white matter in both frontal lobes and insula with edematous changes; these findings were consistent with the acute stage of citrullinemia (CTLN). Mutation analysis of the argininosuccinate synthetase (ASS) gene, in this patient, showed a Gly324Ser mutation in exon 13, and a 67-bp duplication mutation in exon 15 (c.1128-6_1188dup67). The patient was confirmed as having late-onset CTLN1 and treated with anticonvulsants, lactulose enema, protein restricted diet and arginine. Here we describe a case of late-onset CTLN1 in a patient by biochemical analyses and ASS gene mutation confirmation. This is the first report of a Korean patient with late-onset CTLN1 confirmed by ASS gene mutation identification.

• Journal of the Korea Organic Resources Recycling Association
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• v.1 no.1
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• pp.115-125
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• 1993

In Euglena gracilis arginine deiminase was located in the mitochondrial matrix. The highly purified enzyme required $Co^{2+}$ for the enzyme reaction with the $K_m$ value of 0.23 nM, and its optimum pH was 9.7 to 10.3. The molecular weight of the native enzyme protein was 87,000 by gel filtration, and SDS-acrylamide gel electrophoresis showed that the enzyme consisted of two identical subunits with a molecular weight of 48,000. Euglena arginine deiminase was inhibited by sulfhydryl inhibitors, indicating that a sulfhydryl group is involved in the active center of the enzyme. It exhibited negative cooperativity in binding with arginine. $L-{\alpha}-amino-{\beta}-guanidino-propionate$, D-arginine, and L-homoarginine strongly inhibited the enzyme while ${\beta}-guanidinopro-pionate$, ${\gamma}-guanidinobutyrate$, and guanidinosuccinate did not. Considerable inhibition was also observed with citrulline and ornithine. We discuss the effects of the unique properties of the Euglena arginine deiminase on the regulation of arginine metabolism in this protozoon.

• Biomolecules & Therapeutics
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• v.7 no.2
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• pp.105-111
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• 1999

Nitric oxide (NO), a cellular messenger synthesized from L-arginine by NO synthase (NOS, EC.1.14.13.39), is considered to be a regulator of gastric secretion. In the present study, the role of NO in the regulation of exocrine secretion was investigated in rat gastric chief cells. Treatment of chief cells with carba-chol resulted in an increase in the arginine conversion to citrulline, the amount of $NO_{x}$, the release of pepsine-gen, and the level of cGMP Especially, carbachol-stimulated increase of arginine to citrulline transformation, the amount of $NO_{x}$, cGMP level and the release of pepsinogen were partially reduced by the natural NOS inhibitor, $N^{G}$-monomethyl-L-arginine (MMA) and $N^{G}$, $N^{G}$-dimethyl-L-arginine (DMA). Furthermore, MMA- and DMA-induced decrease of pepsinogen secretion showed dose-dependent patters. Activation of NOS is one of the early events in receptor-mediated cascade of reactions in gastric chief cells and NO, not completely, but partially mediates gastric secretion. Agonist-stimulated pepsinogen secretion in chief cells has been considered to be mediated in adenosine 3',5'-cyclic monophosphate pathway and/or guanosine 3', 5'-cyclic monophosphate (cGMP) pathway. Taken together, the above results suggest that partial decrease of exocrine secretion following treatment of NOS inhibitor may result from the inactivation of NOS and subsequent guano- late cyclase, and NO/cGMP pathway may play a pivotal role in exocrine secretion.

• Microbiology and Biotechnology Letters
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• v.27 no.4
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• pp.292-297
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• 1999

Overproduction of L-ornithine by mutant strains isolated from Brevibacterium detoglutamicum BK1046 was investigated. The strain was a L-ornithine auxotroph and exhibited culture instability during fermentation. Through a sequential screening effort, a highly stable strain with lless revertant formation was finally selected and designated B. ketoglutamicum BK52 (KCTC0141BP). It prouduced L-ornithine at a high concentration (above 9 g/L) independent of subculture or cultivation time, and also had a very low tendency of revertant formation. In a long-term storage, this strain maintained its cell stability and productivity of L-ornithine to a reasonable range.

• Journal of Yeungnam Medical Science
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• v.24 no.2
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• pp.322-328
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• 2007

Ornithine transcarbamylase (OTC) deficiency is the most common inborn error of urea cycle metabolism; it is inherited in an X-linked manner. The OTC catalyzes the third step of the urea cycle, the conversion of ornithine and carbamyl phosphate to citrulline. Deficiency of OTC leads to the accumulation of ammonia, causing neurological deficits. In most affected hemizygote males, OTC deficiency manifests as hyperammonemic coma that often leads to death in the newborn period, and those who recover from the coma may be neurologically impaired due to the sequelae of the hyperammonemic encephalopathy. In some, late-onset manifestations develop. We report a male neonate with early onset OT deficiency that had apnea and was comatous. On mutation analysis using DNA sequencing after polymerase chain reaction (PCR) amplification of the 10 exons, deletions of 10 bases in codon 285, causing a frame shift was detected in exon 8. The mother and a sister were diagnosed as female carriers. Therefore, genetic counseling and the risk assessment could be provided to the family.

• Archives of Pharmacal Research
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• v.23 no.4
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• pp.407-412
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• 2000

The presence of the nitric oxide synthase (NOS) enzyme from Salmonella typhimurium (S. typhimurium) was identified by measuring radiolabeled L-$[^3H]$citrulline and NO, and Western blot analysis. NOS was partially purified by both Mono Q ion exchange and Superose 12HR size exclusion column chromatography, sequentially. The molecular weight of NOS was estimated to be 93.3 kDa by Western blot analysis. The enzyme showed a significant dependency on the typical NOS cofactors; an apparent Km for L-arginine of 34.7 mM and maximum activity between $37^{\circ}C$ and $43^{\circ}C$. The activity was inhibited by NOS inhibitors such as aminoguanidine and $N^{G}$ $N^{G}$-dimethyl-L-arginine. taken together, partially purified NOS in S. typhimurium is assumed to be a different isoform of mammalian NOSs.OSs.

• Biomolecules & Therapeutics
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• v.2 no.2
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• pp.131-135
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• 1994

The effect of ginsenoside (GS) from Panax ginseng on basal and nitro-L-arginine suppressed nitric oxide (NO) production was studied in rat kidney. NO production was determined by conversion to [$^{14C}$]=L-citrulline from [$^{14C}$]-L-arginine both in whole kidney and three renal segments; glomerulus, cortex excluding glomerulus (cortex-) and medulla. Nitro-L-arginine (total dose of 30 mg/kg/3 days, i.p.) significantly reduced NO production in whole kidney, which was prevented by GS pretreatment (30 mg/kg/3 days, i.p.). Relative high dose of GS (120 mg/kg/4 days, i.p..) selectively increased NO production in glomerulus and cortex-. Protein content, on wet weight basis, in cortex- and glomerular DNA content were significantly reduced by GS. Our results confirm the existence of constitutive nitric oxide synthase in kidney and it seems that target nephron segment for volume expansion due to GS'NO-mediated vasodilation and for NO production stimulated by GS is cortex including glomerulus.lus.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.143-150
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• 2023

Sarcopenia is a condition in which muscle mass, strength, and performance decrease with age. It is associated with chronic diseases such as diabetes, cardiovascular disease, and hypertension, and contributes to an increase in mortality. Because managing sarcopenia is critical for maintaining good health and quality of life for the elderly, the condition has sparked concern among many researchers. To counteract sarcopenia, intake of protein is an important factor, while a lack of either protein or vitamin D is a major cause of sarcopenia. In addition, essential amino acids, leucine, β-hydroxy β-methylbutyrate (HMB), creatine, and citrulline are used as supplements for muscle health and are suggested as alternatives for controlling sarcopenia. There are many studies on such proteins and supplements, but it is necessary to actually organize the types, amounts, and methods by which proteins and supplements should be consumed to inhibit sarcopenia. In this study, the efficacy of proteins and supplements for controlling sarcopenia according to human clinical studies is summarized to provide suggestions about how the elderly may consume proteins, amino acids, and other supplements.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.15 no.1
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• pp.29-34
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• 2015

Citrullinemia type1 is an autosomal recessive disorder of the urea cycle characterized by neonatal or late onset of hyperammonemia caused by a deficiency of the enzyme argininosuccinate synthetase (ASS). An ASS1 deficiency demonstrates fatal clinical manifestations that are characterized by the neonatal metabolic coma and early death when untreated. It causes a broad spectrum of effects, ranging from a mild disorder to a severe mental retardation, epilepsy, neurologic deficits. An acute neonatal form is the most common. Infants are normal at birth followed by an acute illness characterized by vomiting, lethargy, seizures and coma. These medical problems are life-threatening in many cases. A later onset form is less frequent and may be milder than the neonatal form. This later-onset form is associated with severe headaches, visual dysfunction, motor dysfunction, and lack of energy. Citrullinemia type1 is caused by mutations in the ASS1 gene located on chromosome 9q34.1 that encodes argininosuccinate synthetase, the third enzyme of the urea cycle catalyzing the formation of argininosuccinic acid from citrulline and aspartic acid. The enzyme is distributed in tissues including liver and fibroblasts. This mutation leads to hyperammonemia, arginine deficiency and elevated citrulline level. In the urea cycle, argininosuccinate synthetase catalyses the conversion of citrulline and aspartate to argininosuccinate.. Here, we describe a female newborn patient with lethargy, rigidity and hyperammonemia who was diagnosed as citrullinemia type1 with a c.[421-2A>G], c.[1128-6_1188dup] mutation.