We investigated the action of NOS inhibitors on NOS in rats. Both of nitric oxide synthase inhibitors, NG-monomethyl-L-arginine (L-NMMA, 3 micrometer) or NG-nitro-L-arginine methylester (L-NAME, 30 micrometer), augmented phenylephrine (PE, 10-7 M)-induced contraction which was inhibited by acetylcholine (ACh) in rat thoracic aorta. This augmentation by L-NAME or L-NMMA was attenuated with the treatment of NO precursor, arginine. ACh, however, decreased the augmentation induced by L-NMMA, but not by L-NAME. Superoxide dismutase (SOD, 50 u/ml) potentiated an inhibitory effect of ACh on the PE (10-7 M)-induced contraction. It has been known that platelet activating factor itself induces iNOS. Platelet activating factor (PAF, 10-7 M) inhibited PE (10-7 M)-induced contraction. Pretreatment with L-NMMA (30 mM) or L-NAME (30 mM) significantly blocked the inhibitory action of PAF on PE-induced contraction. L-NMMA (100 mM) or L-NAME (100 mM) reduced nerve conduction velocity (NCV) relevant to nNOS in rat sciatic nerve. ACh attenuated the reduction of NCV by L-NMMA-, but not by L-NAME-induced reduction of NCV. These results suggest that L-NMMA and/or L-NAME have different action on three types of NOS in rats.
Acetylcholine ; Animals ; Aorta, Thoracic ; Arginine ; Neural Conduction ; NG-Nitroarginine Methyl Ester ; Nitric Oxide Synthase* ; Nitric Oxide* ; Nitroarginine ; omega-N-Methylarginine ; Phenylephrine ; Platelet Activating Factor ; Rats* ; Sciatic Nerve ; Superoxide Dismutase

BACKGROUND/AIMS: Amino acids have many physiological activities. We report the correlation between gastric emptying and gastric adaptive relaxation using tryptophan and amino acids with a straight alkyl chain, hydroxylated chain, and branched chain. Here we sought to further clarify the correlation between gastric emptying and gastric adaptive relaxation by using other amino acids. METHODS: In Sprague-Dawley rats, gastric emptying was evaluated by a breath test using [1-¹³C] acetic acid. The expired ¹³CO₂ pattern, T(max), C(max), and AUC(120min) values were used as evaluation items. Gastric adaptive relaxation was evaluated in a barostat experiment. Individual amino acids (1 g/kg) were administered orally 30 minutes before each breath test or barostat test. RESULTS: L-phenylalanine and L-tyrosine did not influence gastric emptying. All other amino acids, ie, L-proline, L-histidine, L-cysteine, L-methionine, L-aspartic acid, L-glutamic acid, L-asparagine, L-arginine, L-glutamine, and L-lysine significantly delayed and inhibited gastric emptying. L-Cysteine and L-aspartic acid significantly enhanced and L-methionine and L-glutamine significantly inhibited gastric adaptive relaxation. L-Phenylalanine moved the balloon toward the antrum, suggesting strong contraction of the fundus. T(max) showed a significant positive correlation (r = 0.709), and C(max) and AUC(120min) each showed negative correlations (r = 0.613 and 0.667, respectively) with gastric adaptive relaxation. CONCLUSION: From the above findings, it was found that a close correlation exists between gastric emptying and adaptive relaxation, suggesting that enhanced gastric adaptive relaxation inhibits gastric emptying.
Acetic Acid ; Amino Acids* ; Animals ; Arginine ; Asparagine ; Aspartic Acid ; Breath Tests ; Cysteine ; Gastric Emptying* ; Glutamic Acid ; Glutamine ; Histidine ; Lysine ; Methionine ; Phenylalanine ; Proline ; Rats ; Rats, Sprague-Dawley ; Relaxation* ; Tryptophan ; Tyrosine

Urinary tract calculi composed primarily of cystine are rare in adults and children. These are usually pure and found exclusively in patients with cystinuria. Cystinuria is an inherited defect in renal tubular reabsorption of four amino acids, cystine, ornithine, lysine, and arginine. Herein we report on a 2 and 1/12 years old male child with a right renal stone and multiple bladder stones composed primarily of cystine which were confirmed by X-ray diffraction method post-operatively.
Adult ; Amino Acids ; Arginine ; Calculi ; Child ; Cystine* ; Cystinuria ; Humans ; Lysine ; Male ; Ornithine ; Urinary Bladder Calculi ; Urinary Tract ; X-Ray Diffraction

BACKGROUND: The selection of identification (ID) system of Enterobacteriaceae depends mainly on accuracy of identification system, cost of operation and convenience of testing. Commercial ID kits are easy to use but too expensive. Therefore, we designed a computerized ID system based on 10 tubes which were composed of 14 conventional biochemical tests to identify the Enterobacteriaceae and Vibrionaceae. The purpose of this present study was to assess the clinical usefulness of 10 tube system as an identification system for Enterobacteriaceae in clinical microbiology laboratories. METHODS: During the period of January 1998, 189 Enterobacteriaceae and 2 Aeromonas spp. consecutively isolated from clinical specimens were simultaneously identified by 10 tube system and the API rapid ID 32 E. Fourteen conventional biochemical tests used in 10 tube system were lactose, sucrose, and H2S in Kligler's iron agar media; motility, indole, and ornithine decarboxylase in motility-indole-ornithine decarboxylase agar media; citrate, urease, lysine decarboxylase, phenylalanine deaminase, arginine dihydrolase, arabinose, trehalose, and adonitol. Identification program used in 10 tube system were % ID method and ID score method. RESULTS: Among the 191 isolates, agreement rate of identification between 10 tube system and API rapid ID 32 E were 96.0% to the species level and 99.4% to the genus level. And identification accuracy of 10 tube system was 90.6% to the species level and 93.2% to the genus level. CONCLUSIONS: 10 tube system has been shown to be an accurate, cost-effective alternative to the use of commercial kit systems for identification of Enterobacteriaceae.
Aeromonas ; Agar ; Arabinose ; Arginine ; Citric Acid ; Enterobacteriaceae* ; Iron ; Lactose ; Lysine ; Ornithine Decarboxylase ; Phenylalanine ; Ribitol ; Sucrose ; Trehalose ; Urease ; Vibrionaceae

Cystinuria is an autosomal recessive inherited defect in renal tubular reabsorption of four amino acids, cystine, ornithine, lysine and arginine. Homozygotes were identified by the formation of urinary tract calculi composed of cystine and by gross hyperexcretion of above mentioned four amino acids. Urinary tract calculi composed primarily of cystine are rare in adults and children. These are usually pure and found exclusively in patients with cystinuria. Herein we report on a 4 and 3/12 years old male child with a right renal stone composed primarily of cystine which was confirmed by chemical analysis method postoperatively. After discharge he has been treated with D-penicillamine, large fluid intake and conversion of urine pH.
Adult ; Amino Acids ; Arginine ; Calculi ; Child* ; Cystine* ; Cystinuria ; Homozygote ; Humans ; Hydrogen-Ion Concentration ; Lysine ; Male ; Ornithine ; Penicillamine ; Urinary Tract

OBJECTIVES: Carboplatin, a platinum-containing anti-cancer drug used to treat a variety of cancers, induces ototoxicity. Since, reactive oxygen species (ROS) and nitric oxide (NO) seem to be responsible for this toxicity, the antioxidant, N-acetyl-L-cysteine (L-NAC), and NO synthetase inhibitor, N-nitro-L-arginine methyl ester (L-NAME) were predicted to have protective effects against carboplatin ototoxicity. The aim of this study was to test for the protective effects of L-NAC and L-NAME on cochlear hair cells and spiral ganglion neurons (SGNs). METHODS: Cochlear organotypic cultures and dissociated spiral ganglion neuron cultures, from mice postnatal day 5 cultures were used in this study. The cultures were treated with carboplatin alone or in combination with L-NAC or L-NAME, and carboplatin-induced damage was monitored. RESULTS: Treatment with carboplatin induced a significant loss of outer hair cells, while inner hair cells were preserved in the cochlear organotypic cultures. Addition of L-NAC or L-NAME reduced the amount of carboplatin-induced hair cell damage; the differences did not reach statistical significance. However, carboplatin significantly decreased the number of surviving SGNs in dissociated cultures. The toxic effects were significantly reduced by addition of L-NAC or L-NAME. In addition, carboplatin induced the loss of neurites from the SGN somata, and this was not blocked with L-NAC or L-NAME. CONCLUSION: The results of this study suggest that ROS and NO are involved in carboplatin-induced damage to hair cells and SGNs, and administration of L-NAC/L-NAME can be used to attenuate the toxicity.
Acetylcysteine ; Animals ; Carboplatin ; Hair ; Ligases ; Lysine ; Mice ; Neurites ; Neurons ; NG-Nitroarginine Methyl Ester ; Nitric Oxide ; Reactive Oxygen Species ; Spiral Ganglion

OBJECTIVES: Carboplatin, a platinum-containing anti-cancer drug used to treat a variety of cancers, induces ototoxicity. Since, reactive oxygen species (ROS) and nitric oxide (NO) seem to be responsible for this toxicity, the antioxidant, N-acetyl-L-cysteine (L-NAC), and NO synthetase inhibitor, N-nitro-L-arginine methyl ester (L-NAME) were predicted to have protective effects against carboplatin ototoxicity. The aim of this study was to test for the protective effects of L-NAC and L-NAME on cochlear hair cells and spiral ganglion neurons (SGNs). METHODS: Cochlear organotypic cultures and dissociated spiral ganglion neuron cultures, from mice postnatal day 5 cultures were used in this study. The cultures were treated with carboplatin alone or in combination with L-NAC or L-NAME, and carboplatin-induced damage was monitored. RESULTS: Treatment with carboplatin induced a significant loss of outer hair cells, while inner hair cells were preserved in the cochlear organotypic cultures. Addition of L-NAC or L-NAME reduced the amount of carboplatin-induced hair cell damage; the differences did not reach statistical significance. However, carboplatin significantly decreased the number of surviving SGNs in dissociated cultures. The toxic effects were significantly reduced by addition of L-NAC or L-NAME. In addition, carboplatin induced the loss of neurites from the SGN somata, and this was not blocked with L-NAC or L-NAME. CONCLUSION: The results of this study suggest that ROS and NO are involved in carboplatin-induced damage to hair cells and SGNs, and administration of L-NAC/L-NAME can be used to attenuate the toxicity.
Acetylcysteine ; Animals ; Carboplatin ; Hair ; Ligases ; Lysine ; Mice ; Neurites ; Neurons ; NG-Nitroarginine Methyl Ester ; Nitric Oxide ; Reactive Oxygen Species ; Spiral Ganglion

AIMS OF STUDY: During reflex micturition, the urethral outlet remains open (relaxed) to promote urinary emptying. The mechanisms involved in the relaxation of urethral outlet is thought to be complex including nitric oxide (NO) pathway and beta-adrenergic activity. The aims of the study focused on these several issues related to the neural control of urethral outlet in vivo. MATERIALS & METHODS: Female rats weighing 200~300 gm were anesthetized wish urethane. Catheters were inserted into femoral artery for drug administration.4 two-way catheter (16 G angiocath) was inserted into the bladder for saline infusion and pressure monitoring. A separate cannula (PE 50) was placed into the urethra via external urethral meatus or proximal urethrat opening to record urethral pressure. The bladder was filled with saline at a rate of 0.1 ml/min to induce reflex micturition. Urethral pressure was recorded via cannula through which saline was infused at a rate of 0.05 ml/min. Isovolumetric bladder contraction and urethral pressure were recorded simultaneously. After an equilibration period of 30 minutes, baseline intravesical and urethral pressure were recorded for 10 minutes prior to drug administration. NG-nitro-L-arginine methylester (L-NAME, 10 to 15 mg/kilrogram, i.v.), L-arginine (150 mg/kilrogram, i.v.), propranolol (1 microM., 0.1 ml/250 mg, i.a.), and phenylephrine (1 0~100 microM, i.a.) were administrated. RESULTS: During isovolumetric bladder contraction, urethral pressure was decreased simultaneously, and then returned to the resting states in conjunction with end of the bladder contraction. After the administration of L-NAME, the magnitude of reflex urethral relaxation was decreased significantly (42.6 +/- 15.1% of the control, p<0.01), and this effect was reversed by addition of L-arginine. Administration of propranolol also inhibited urethral relaxation (66.4% of the control). Administration of L-NAME followed by propranolol almost completely abolished the urethral relaxation. Administration of phenylephrine increased the resting urethral tone (mean; 4 cmH2O) significantly, and the magnitude of urethral relaxation was decreased substantially. CONCLUSION: These RESULTS suggest that urethral relaxation is mediated by several neural factors. NO seems like to a potent mediator in a reflex relaxation of the urethral smooth muscle during micturition. Also, beta-adrenergic stimulation play an important role for urethral relaxation. alpha-adrenergic nerve discharge, contributed to contraction of urethral smooth muscle, shows inhibitory effect against the reflex urethral relaxation.
Animals ; Arginine ; Catheters ; Female ; Femoral Artery ; Humans ; Muscle, Smooth ; NG-Nitroarginine Methyl Ester ; Nitric Oxide* ; Nitroarginine ; Phenylephrine ; Propranolol ; Rats ; Reflex ; Relaxation* ; Urethane ; Urethra ; Urinary Bladder ; Urination

BACKGROUND: Propofol decreases arterial blood pressure. This has been ascribed to vasodilation and decreased cardiac output occurring separately or in combination. This study investigated the relaxant effects of propofol and the effects of L-arginine and L-NAME on the vasodilation of propofol in rat thoracic aortic rings. METHODS: Isolated aortic rings were precontracted with phenylephrine (0.01 micrometer -10 micrometer) cumulatively and 10 minutes before the precontracted phenylephrine treatment, propofol was added cumulatively (1 micrometer-10 micrometer). The effects of L-NAME and L-arginine were evaluated by applying L-NAME (10 micrometer) and L-arginine (10 micrometer) after added propofol and before precontracted phenylephrine. RESULTS: A low concentration of propofol (1 micrometer) did not reduce phenylephrine-induced contraction but a high concentration of propofol (over 10 micrometer) reduced it significantly. Propofol also relaxed rat thoracic aortic rings in an endothelium independent manner. The L-NAME and L-arginine treatment did not affect the propofol-induced relaxation. CONCLUSIONS: Propofol was shown to have a biphasic vasoactive effect on rat thoracic aorta rings. The vasodilation effect of propofol was not related to the production of nitric oxide.
Animals ; Aorta, Thoracic ; Arginine* ; Arterial Pressure ; Cardiac Output ; Endothelium ; NG-Nitroarginine Methyl Ester ; Nitric Oxide ; Phenylephrine ; Propofol* ; Rats* ; Relaxation ; Vasodilation*

Hypoxic pulmonary vasoconstriction(HPV) plays an important role in matching ventilation and perfusion, and in a homeostatic compensatory mechanism for maintaining arterial blood oxygen tension. The purpose of this study was to explore effect of hypoxia on the vascular tension and to elucidate mechanism underlying hypoxic pulmonary vasoconstriction. The ring segments of the pulmonary artery were taken from forty rabbits(2~2.5 kg, male). Each ring was attached to an isometric force transducer(Grass FT-03) and suspended in a tissue bath(37degrees C) filled with 5 ml Krebs solution, aerated with 95% O2 + 5% CO2(pH 7.4) gas mixture. During 90 minutes of equilibrium period, the Krebs solution was changed every 15 minutes and the last resting tension was adjusted to 2 gm. After precontraction of the preparations with K(+) 40 mM, the aerating gas mixture was replaced by hypoxic gas(95% N2 + 5% CO2) and changes in vascular tension of isolated pulmonary artery with(n=36) and without endothelium(n=14) were recorded for 60 minutes. HPV induced biphasic vasoactive effects. To determine the mechanism of the vasorelaxing response, the pulmonary arterial rings were pretreated with indomethacin(n=8), L-nitro(w) arginine methyl ester(L-NAME, n=l0), tetra ethyl ammonium(TEA, n=12), glybenclamide(n=l1). And also to elucidate the mechanism of the hypoxic vasoconstricting response, effects of Ca free solution and pretreatment of ryanodine on the HPV were examined. The results obtained were as follows: 1) Transient phase 1 contraction followed by long lasting(about 30 minutes) relaxation and sustained phase 2 contraction were induced by hypoxic gas(95% N2+5% CO2) in rabbit pulmonary artery. 2) In endothelium removed pulmonary artery, transient phase 1 contraction was not apparent. 3) Vasorelaxation was partially blocked by K' channel blockers(TEA, glybenclamide). 4) Indomethacin and L-NAME pretreatments did not affect on the vasorelaxing response of the HPV to hypoxia. 5) Sustained phase 2 contraction was blocked by calcium free Krebs solution. 6) Indomethacin and ryanodine pretreatments did not change the phase 1 and phase 2 vasocontsricting reponses. The results of present study suggest that hypoxia-induced phase 1 contractile response is endothelium dependent, while phase 2 contractile response is dependent on calcium influx, and that the vasorelaxant response is partially mediated by K(+) channel.
Anoxia ; Arginine ; Calcium ; Characidae ; Endothelins ; Endothelium ; Indomethacin ; NG-Nitroarginine Methyl Ester ; Oxygen ; Perfusion ; Pulmonary Artery* ; Relaxation ; Ryanodine ; Vasoconstriction* ; Vasodilation ; Ventilation