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Biomedical subjects

K Takeuchi

Publications and source records attributed to K Takeuchi.

At least 145 records · Page 8Linked to original sources

The roles of prostaglandin E receptor subtypes in the cytoprotective action of prostaglandin E2 in rat stomach.

AIM: To investigate the EP receptor subtype involved in the gastroprotective action of prostaglandin (PG) E2 using various EP receptor agonists in rats, and using knockout mice lacking EP1 or EP3 receptors. METHODS: Male SD rats and C57BL/6 mice were used after an 18-h fast. Gastric lesions were induced by oral administration of HCl/ethanol (150 mM HCl in 60% ethanol). Rats were given various EP agonists i.v. 10 min before HCl/ethanol: PGE2, sulprostone (EP1/EP3 agonist), butaprost (EP2 agonist), 17-phenyl-omega-trinorPGE2 (17-phenylPGE2: EP1 agonist), ONO-NT012 (EP3 agonist) and 11-deoxyPGE1 (EP3/EP4 agonist). In a separate study, the effect of PGE2 on HCl/ethanol lesions was examined in EP1- and EP3-receptor knockout mice. RESULTS: Gastric lesions induced by HCl/ethanol were dose dependently prevented by PGE2: this effect was mimicked by sulprostone and 17-phenylPGE2 and was significantly antagonized by ONO-AE-829, an EP1 antagonist. Neither butaprost, ONO-NT012 nor 11-deoxyPGE1 exhibited any protective activity against HCl/ethanol-induced gastric lesions. PGE2 caused an inhibition of gastric motility as well as an increase of mucosal blood flow and mucus secretion, the effects being mimicked by prostanoids activating EP1 receptors, EP2/EP3/EP4 receptors and EP4 receptors, respectively. On the other hand, although HCl/ethanol caused similar damage in both wild-type mice and knockout mice lacking EP1 or EP3 receptors, the cytoprotective action of PGE2 observed in wild-type and EP3-receptor knockout mice totally disappeared in mice lacking EP1 receptors. CONCLUSION: The gastric cytoprotective action of PGE2 is mediated by activation of EP1 receptors. This effect may be functionally associated with inhibition of gastric motility but not with increased mucosal blood flow or mucus secretion.

Animals↗

Interactive roles of endogenous prostaglandin and nitric oxide in regulation of acid secretion by damaged rat stomachs.

BACKGROUND: The acid inhibitory mechanism in the damaged stomach is known to involve endogenous nitric oxide (NO) as well as prostaglandin (PG). AIM: To investigate the interaction between PG and NO in regulation of acid secretion in the stomach following damage. METHODS: Under urethane anaesthesia, a rat stomach was mounted in an ex vivo chamber and perfused with saline. Acid secretion, luminal PGE2, NO metabolites (NOx) and histamine output were measured before and after application of 20 mM taurocholate Na (TC) for 30 min, with or without pre-treatment with indomethacin and/or N(G)-nitro-L-arginine methyl ester (L-NAME). RESULTS: Exposure of the stomach to TC caused a decrease in acid secretion, with concomitant increase of both luminal NOx and PGE2. Either L-NAME or indomethacin reduced the decrease in acid secretion in response to TC, but only L-NAME allowed acid secretion to increase over basal values. L-NAME prevented the increase of luminal NOx after TC treatment, while indomethacin inhibited PGE2 release during and after exposure to TC. The increase in acid secretion in the presence of L-NAME was prevented when indomethacin was given concomitantly. TC treatment increased histamine output in the lumen, a process that was enhanced by L-NAME but reduced by indomethacin. CONCLUSIONS: Damage to the stomach increases both NO and PG in the lumen, and decreases acid secretion. Inhibiting NO production increases acid secretion in the damaged stomach, but only when PG biosynthesis is intact. It is assumed that endogenous PG has a dual role in the regulation of acid secretion in the damaged stomach: an inhibitory effect at the parietal cell and an excitatory effect probably through enhancing the release of mucosal histamine.

Animals↗

The Vdelta1 T cell receptor repertoire in human nasal mucosa.

The gamma/delta T cells play important roles as the first line of defence in mucosal immunity. Vdelta1 bearing T cells comprise the major population of gamma/delta T cells in the human nasal mucosa. Recently, it was reported that certain receptors are predominant at given anatomical locations. The purpose of this study was to elucidate the gamma/delta T-cell receptor repertoire in human nasal mucosa. Nasal epithelia were scraped and peripheral blood were obtained from three healthy volunteers. We performed reverse-transcription polymerase chain reaction (RT-PCR) analysis and characterized the junctional sequences of Vdelta1 T-cell receptor (TCR) transcripts. Vgamma and Vdelta gene usage in intraepithelial lymphocytes (IELs) in right and left nasal mucosa were almost the same, but they were different from those in peripheral blood lymphocytes (PBLs). The VDJ sequence of nasal Vdelta1 T-cell receptor transcripts showed diversity and were different for each individual. Vdelta1 in the IELs were rearranged to Jdelta1 and Vdelta1 in the PBLs were rearranged not only to Jdelta1 but also to Jdelta3. Vdelta1 sequences in the IELs in the nasal mucosa showed no overlap with those in the PBLs. These results indicate that gamma/delta T cells in the nose are organ specific lymphocytes.

Adult↗

Independent pathways leading to apoptotic cell death, oxidative burst and defense gene expression in response to elicitin in tobacco cell suspension culture.

We characterized pharmacologically the hypersensitive cell death of tobacco BY-2 cells that followed treatments with Escherichia coli preparations of INF1, the major secreted elicitin of the late blight pathogen Phytophthora infestans. INF1 elicitin treatments resulted in fragmentation and 180 bp laddering of tobacco DNA as early as 3 h post-treatment. INF1 elicitin also induced rapid accumulation of H2O2 typical of oxidative burst, and the expression of defense genes such as phenylalanine ammonia-lyase (PAL) gene at 1 h and 3 h after elicitin treatment, respectively. To investigate the involvement of the oxidative burst and/or the expression of defense genes in the signal transduction pathways leading to hypersensitive cell death, we analyzed the effect of several chemical inhibitors of signal transduction pathways on the various responses. The results indicated that (a) the cell death required serine proteases, Ca2+ and protein kinases, (b) the oxidative burst was involved in Ca2+ and protein kinase mediated pathways, but elicitin-induced AOS was neither necessary nor sufficient for cell death and PAL gene expression, and (c) the signaling pathway of PAL gene expression required protein kinases. These results suggest that the three signal transduction pathways leading to cell death, oxidative burst and expression of defense genes branch in the early stages that follow elicitin recognition by tobacco cells.

Algal Proteins↗

Regulatory mechanism of acid secretion in the damaged stomach: role of endogenous nitric oxide.

The present article overviews the regulatory mechanism of acid secretion in the stomach after damage with taurocholate (TC), one of the bile acids. Mucosal exposure of a rat stomach to 20 mmol/L TC for 30 min caused a decrease of acid secretion with a concomitant increase in nitric oxide (NO) and prostaglandin (PG) E2 (PGE2) as well as Ca2+ in the luminal contents. Prior administration of N(G)-nitro-L-arginine methyl ester (L-NAME), as well as indomethacin, significantly attenuated the reduction of acid secretion by TC and acid secretion was even increased in the presence of L-NAME. The acid stimulatory effect of L-NAME in the damaged stomach was not mimicked by aminoguanidine and was antagonized by co-administration of L-arginine but not D-arginine. Increased NO release in the damaged stomach was suppressed by pretreatment with L-NAME or co-application of EGTA and the latter also inhibited the increase in luminal Ca2+. The enhanced acid secretory response in the presence of L-NAME was also inhibited by cimetidine, FPL-52694 (a mast cell stabilizer) or sensory deafferentation. Mucosal exposure to TC caused an increase in luminal histamine output, together with a decrease in the number of mucosal mast cells in the stomach. These changes were prevented by FPL-52694 and sensory deafferentation and were also partly suppressed by indomethacin. In addition, the acid stimulatory action of L-NAME in the damaged stomach was significantly mitigated when indomethacin was administered together with L-NAME. We conclude that: (i) damage in the stomach may activate acid a stimulatory pathway in addition to a PG-, NO- and Ca2+-dependent inhibitory mechanism, but the latter effect overcomes the former, resulting in a decrease in acid secretion; (ii) acid stimulation in the damaged stomach is mediated by histamine released from the mucosal mast cell, a process interacting with capsaicin-sensitive sensory nerves; (iii) the increase in luminal Ca2+ plays a role in increasing NO production and, hence, in regulating acid secretion; and (iv) PG may have a dual role in the regulation of acid secretion in the damaged stomach: an inhibitory effect at the parietal cell and an excitatory effect, probably through enhancing the release of mucosal histamine.

Animals↗

Duodenal somatostatinoma: a case report and review of 31 cases with special reference to the relationship between tumor size and metastasis.

Somatostatinomas are rare functioning neoplasms usually arising in the pancreas and duodenum. We report a case of somatostatinoma in a 42-year-old male with neither neurofibromatosis nor somatostatinoma syndrome. A large tumor in the descending duodenum had given rise to multiple lymph node metastases. An additional 31 duodenal somatostatinoma cases were also reviewed. Most originated in the descending part of the duodenum, with the ampulla and peri-ampullary area as the most common sites (60%). Frequent manifestations were abdominal pain (25%), jaundice (25%), or cholelithiasis (19%), the latter two reflecting obstruction of the bile duct by tumors. Only two cases showed a possible somatostatinoma syndrome (6%). The tumors with metastases, lymph nodes (10) and liver (2), were significantly larger than average than those without (2.91 +/- 1.49 cm vs 1.36 +/- 0.71 cm, P < 0.05). With a cut-off point of 2.0 cm, diagnostic accuracy for metastasis was 77.78% with 87.50% specificity and 63.64% sensitivity. The smallest tumor with metastases was 0.8 cm and the largest without metastases was 3.0 cm. These results indicate that duodenal somatostatinomas are malignant by nature and the risk of metastasis significantly increases with tumors larger than 2.0 cm.

Adult↗

Cardiac strangulation in a neonatal case: a rare complication of permanent epicardial pacemaker leads.

A newborn female underwent pacemaker implantation with epicardial pacing leads for the treatment of bradycardia caused by congenital atrioventricular block. At 10 months after pacemaker implantation, she was admitted with congestive heart failure. The epicardial leads were seen to encircle the heart, and myocardial ischemia was suggested. During cardiac catheterization she collapsed: emergency operation was performed, but she died on postoperative day 6.

Bradycardia↗

Cardiac performance after deep hypothermic circulatory arrest in chronically cyanotic neonatal lambs.

OBJECTIVES: It is controversial whether immature cyanotic hearts are more susceptible to ischemic injury than normoxemic hearts. Acutely induced alveolar hypoxic stress before cardiopulmonary bypass has been used as a model of cyanosis and is reported to worsen recovery of immature hearts after subsequent ischemic insult by means of a free radical injury mechanism. Because of concerns about the relevance of acute alveolar repair to the chronic cyanosis encountered clinically, we assessed the effects of chronic cyanosis without alveolar hypoxia, acute alveolar hypoxia, and normoxemia on recovery of cardiac function after deep hypothermic circulatory arrest. METHODS: A chronic cyanosis model was created in 8 lambs by an anastomosis between the pulmonary artery and the left atrium (cyanosis group). Eight lambs underwent sham operation (control). One week later, the animals underwent cardiopulmonary bypass with 90 minutes of deep hypothermic circulatory arrest at 18 degrees C. Another 8 lambs underwent 45 minutes of hypoxic ventilation before bypass, with arterial oxygen tension being maintained at 30 mm Hg (acute hypoxia group). Cardiac index, preload recruitable stroke work, and tau were measured. Malondialdehyde and nitrate-nitrite, nitric oxide metabolites, were also measured in the coronary sinus. Myocardial antioxidant reserve capacity at 2 hours of reperfusion was assessed by measuring lipid peroxidation in left ventricular tissue samples incubated with t-butylhydroperoxide at 37 degrees C. RESULTS: Oxygen tension was 35 +/- 3 mm Hg in the acute hypoxia group versus 93 +/- 7 mm Hg in the control group. In the acute hypoxia group the recovery of cardiac index, preload recruitable stroke work, and tau were significantly worse than that found in both the control and cyanosis groups. Preload recruitable stroke work at 2 hours of reperfusion was slightly but significantly lower in the cyanosis group than in the control group. The postischemic level of nitric oxide metabolites was significantly lower in the acute hypoxia group than in the cyanosis and control groups. However, malondialdehyde levels in the coronary sinus and myocardial antioxidant reserve capacity were not significantly different among the groups. CONCLUSION: Recovery of left ventricular function after deep hypothermic circulatory arrest in neonatal lambs with chronic cyanosis was slightly worse than that found in acyanotic animals. Acute hypoxia before bypass was associated with significantly worse recovery of left ventricular function, and the mechanism of injury may be related to an impairment of nitric oxide production. Free radical injury does not appear to explain any differences among cyanotic, acyanotic, and acutely hypoxic animals in recovery of left ventricular function after ischemia.

Analysis of Variance↗

Molecular mechanism of activation and superactivation of Ret tyrosine kinases by ultraviolet light irradiation.

The catalytic activities of Ret tyrosine kinases as the products of oncogene RET with multiple endocrine neoplasia type 2A (Ret-MEN2A) or 2B (Ret-MEN2B) mutations and the hybrid gene from c-RET and RFP (Rfp-Ret) were higher than those of c-Ret. We demonstrated that ultraviolet light (UV) irradiation induced activation of c-Ret and superactivation of genetically mutated, and thereby constitutively activated, Ret-MEN2A, Ret-MEN2B, and Rfp-Ret. We found that small proportions of c-Ret and Ret-MEN2B and a large proportion of MEN2A were dimerized due to disulfide bonds and that high kinase activity resided in these fractions. The UV-induced activation of c-Ret and superactivation of Ret-MEN2A and Ret-MEN2B were then shown to be closely associated with promotion of the disulfide bond-mediated dimerization of the Ret proteins. Furthermore, we showed that a large proportion of Rfp-Ret was dimerized or polymerized and that almost all kinase activities resided in the highly polymerized but not dimerized fraction. The UV-induced superactivation of Rfp-Ret was also found to be closely associated with promotion of polymerization but not with dimerization of Rfp-Ret. Further experiments revealed that UV induced intracellular dimerization and activation of the extracellular domain-deleted mutant Ret (Ret-PTC-1). Most importantly, the levels of basal kinase activity and dimerization of Ret-TPC-1-C376A, in which cysteine 376 in the tyrosine kinase domain of Ret-TPC-1 was replaced with alanine, were low and were not increased by UV irradiation. These results suggest that the cysteine at this position works as the primary target of dimerization of Ret proteins inside the cell for both the maintenance of the basal kinase activity and its promotion by UV, possibly in co-operation with the cysteine(s) in the extracellular domain of Ret-MEN2A and Rfp-Ret, which is the target of dimerization and polymerization outside the cell. The potential biological significance of the UV-mediated superactivation of mutant Ret through the newly proposed mechanism in oncogenesis is discussed.

Amino Acid Sequence↗

Optimal propofol plasma concentration during upper gastrointestinal endoscopy in young, middle-aged, and elderly patients.

BACKGROUND: Suitable propofol plasma concentrations during gastroscopy have not been determined for suppressing somatic and hemodynamic responses in different age groups. METHODS: Propofol sedation at target plasma concentrations from 0.5 to 4.0 microgram/ml were performed randomly in three groups of patients (23 per group) who were undergoing elective outpatient gastroscopy: ages 17-49 yr (group 1), 50-69 yr (group 2), and 70-89 yr (group 3). Plasma propofol concentration in which 50% of patients do not respond to these different stimuli were determined by logistic regression: verbal command (Cp50ls), somatic response to gastroscopy (Cp50endo), and gag response to gastroscopy (Cp50gag). Hemodynamic responses were also investigated in the different age groups. RESULTS: Cp50ls concentrations were 2.23 microgram/ml (group 1), 1.75 microgram/ml (group 2), and 1.40 microgram/ml (group 3). The Cp50endo values in groups 1 and 2 were 2.87 and 2.34 microgram/ml, respectively, which were significantly higher than their respective Cp50ls values. Cp50endo value in group 3 was 1.64 microgram/ml, which was close to its Cp50ls value. Because of a high degree of interpatient variability, Cp50gag could not be defined. Systolic blood pressure response decreased with increasing propofol concentrations. CONCLUSIONS: The authors determined the propofol concentration necessary for gastroscopy and showed that increasing age reduces it. Propofol concentration that suppresses somatic response induces loss of consciousness in almost all young patients.

Adolescent↗

Tumor necrosis factor gene polymorphism in chronic sinusitis.

OBJECTIVES: It is likely that genetic factors play a role in the etiology of chronic sinusitis, and airway inflammation is an important pathological feature in chronic sinusitis. We hypothesized that individuals with greater inflammatory responses may be more likely to acquire the disease. Polymorphisms of the tumor necrosis factor (TNF) genes have been described, and certain inflammatory diseases are reportedly associated with certain alleles of TNF genes. The purpose of this study is to examine whether there is an association between some alleles of TNF genes and chronic sinusitis. STUDY DESIGN: Thirty-eight Japanese patients with intractable chronic sinusitis were selected on the basis of the following criteria: 1) persistent mucous or mucopurulent nasal discharge and/or postnasal dripping for longer than 3 years and 2) opacification in bilateral maxillary sinuses and ethmoid cells on plain radiographic films. METHODS: Both tumor necrosis factor-alpha (TNF-alpha) and tumor necrosis factor-beta (TNF-beta) gene polymorphisms were analyzed by polymerase chain reaction (PCR) with restriction fragment length polymorphisms in these patients and 35 healthy control subjects. RESULTS: A significantly higher frequency (P < .05) of TNFB*2 allele of TNF-beta gene polymorphism was observed in patients with chronic sinusitis (74%) compared with control subjects (56%). There was no association between alleles of TNF-alpha and chronic sinusitis. CONCLUSION: We concluded that TNF-beta gene polymorphism may form a component of the genetic predisposition to chronic sinusitis in Japanese patients.

Adolescent↗

Calcium concentration and artificial precipitates in human pancreatic juice.

We studied the role of the increase in the calcium concentration in pure pancreatic juice of alcoholic noncalcified chronic pancreatitis. Pure pancreatic juice was obtained endoscopically. The pancreatic juice from patients with chronic pancreatitis was adjusted to pH 7.5; then the calcium concentration was adjusted to 0.4, 2.9, 5.4, or 10.4 mmol/L. Artificial precipitates were produced by incubation of the samples at 37 degrees C for 6 hours. Proteins in the artificial precipitates were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the protein patterns were compared with the patterns of natural protein plugs from patients with chronic pancreatitis. The amount of the precipitate increased as the added calcium increased. The protein patterns of SDS-PAGE of the artificial precipitates were similar to those of protein plugs. Albumin, a-amylase, lipase, trypsinogen, and chymotrypsinogen were identified by immunoblotting both in the precipitate and in the protein plug. The increased calcium concentrations in pancreatic juice induced the formation of precipitates whose protein composition was similar to that of protein plugs. An increased calcium concentration in human pancreatic juice may play an important role in the pathogenesis of protein plugs.

Adult↗

Recovery of pathogenic measles virus from cloned cDNA.

Reverse genetics technology so far established for measles virus (MeV) is based on the Edmonston strain, which was isolated several decades ago, has been passaged in nonlymphoid cell lines, and is no longer pathogenic in monkey models. On the other hand, MeVs isolated and passaged in the Epstein-Barr virus-transformed marmoset B-lymphoblastoid cell line B95a would retain their original pathogenicity (F. Kobune et al., J. Virol. 64:700-705, 1990). Here we have developed MeV reverse genetics systems based on the highly pathogenic IC-B strain isolated in B95a cells. Infectious viruses were successfully recovered from the cloned cDNA of IC-B strain by two different approaches. One was simple cotransfection of B95a cells, with three plasmids each encoding the nucleocapsid (N), phospho (P), or large (L) protein, respectively, and their expression was driven by the bacteriophage T7 RNA polymerase supplied by coinfecting recombinant vaccinia virus vTF7-3. The second approach was transfection with the L-encoding plasmid of a helper cell line constitutively expressing the MeV N and P proteins and the T7 polymerase (F. Radecke et al., EMBO J. 14:5773-5784, 1995) on which B95a cells were overlaid. Virus clones recovered by both methods possessed RNA genomes identical to that of the parental IC-B strain and were indistinguishable from the IC-B strain with respect to growth phenotypes in vitro and the clinical course and histopathology of experimentally infected cynomolgus monkeys. Thus, the systems developed here could be useful for studying viral gene functions in the context of the natural course of MeV pathogenesis.

Animals↗

Sendai virus blocks alpha interferon signaling to signal transducers and activators of transcription.

We demonstrate here that Sendai virus (SeV) blocks alpha interferon (IFN-alpha) signaling to signal transducers and activators of transcription (STATs) in HeLa cells. IFN-alpha-stimulated tyrosine phosphorylation of STATs and subsequent formation of the IFN-stimulated gene factor 3 transcription complex were inhibited in SeV-infected cells, resulting in inefficient induction of IFN-stimulated gene products. None of the components of the signaling pathway-type I IFN receptor subunits Jak1, Tyk2, Stat1, Stat2, and p48-was degraded. Moreover, tyrosine phosphorylation of Jak1 in response to IFN-alpha was unaffected at the early phase of infection, suggesting that oligomerization of the receptor subunits proceeded normally. In contrast to Jak1, IFN-alpha-stimulated tyrosine phosphorylation of Tyk2 was partially inhibited. Therefore, this partial inhibition of activation of Tyk2 probably contributes to the subsequent failure in the activation of STATs.

Cytokines↗

Protective effect of lafutidine against indomethacin-induced intestinal ulceration in rats: relation to capsaicin-sensitive sensory neurons.

BACKGROUND/AIM: We examined the prophylactic effect of lafutidine, a novel histamine H(2)-receptor antagonist [(+/-)-2-(furfurylsulfinyl)-N-[4-[4-(piperidinomethyl)-2-pyr idyl]oxy- (Z)-2 butenyl]acetamide], on indomethacin-induced small intestinal ulcers in rats and investigated the relation of this action to capsaicin-sensitive sensory neurons. METHODS AND RESULTS: Subcutaneously administered indomethacin (10 mg/kg) provoked ulceration in the small intestine, mainly the jejunum and ileum, accompanied by increases in myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activities as well as the enterobacterial numbers invading the mucosa. Intestinal ulcerogenic response to indomethacin was prevented by 16,16-dimethyl prostaglandin E(2) (10 microg/kg, p.o.) and capsaicin (10 mg/kg, p.o. ) as well as ampicillin (800 mg/kg, p.o.), but not omeprazole (100 mg/kg, p.o.). Likewise, lafutidine (1-10 mg/kg, p.o.), but not cimetidine (100 mg/kg, p.o.), reduced the occurrence of intestinal ulcers in response to indomethacin in a dose-dependent manner, and a significant effect was observed at 3 mg/kg or greater. The protective action of lafutidine as well as capsaicin was almost totally abolished by chemical ablation of capsaicin-sensitive sensory neurons. Both lafutidine and capsaicin significantly suppressed the increases in MPO and iNOS activities as well as enterobacterial numbers in the mucosa. These agents also significantly enhanced mucus secretion in the small intestine. CONCLUSION: These results suggest that lafutidine protects the small intestine against ulceration via stimulation of capsaicin-sensitive sensory neurons. This action may be attributable to inhibition of enterobacterial invasion in the intestinal mucosa, probably by increasing the mucus secretion.

16,16-Dimethylprostaglandin E2↗

Effect of ecabet disodium, a novel locally-acting antiulcer drug, on epithelial restitution following injury by hypertonic NaCl in bullfrog stomach in vitro.

BACKGROUND: The antiulcer drug ecabet 2Na (12-sulfodehydroabietic acid disodium salt) exhibits a gastroprotective activity, mainly through a local action, involving endogenous prostaglandins (PGs) and nitric oxide (NO). In the present study, we examined the effect of ecabet on the epithelial restitution of the bullfrog gastric mucosa in vitro following injury by hypertonic NaCl. METHODS: Bullfrog fundic mucosa was mounted in an Ussing chamber. The tissue injury was induced by exposure of the mucosa to 1.25 M NaCl for 5 min, and transmucosal potential difference (PD) and electrical resistance (R) were measured during a 4-hour test period. Ecabet (3-30 mg/ml) was added to the luminal solution for 10 min before or after NaCl, while 16,16-dimethyl PGE(2) (dmPGE(2): 1x 10(-6) M) or NOR-3 (a NO donor: 1 x 10(-4) M) was added to the nutrient solution 10 min before NaCl. RESULTS: Mucosal application of 1.25 M NaCl caused an immediate reduction of PD and R, followed by a gradual normalization, reaching about 70% of the pre-exposure levels within 4 h. Ecabet, added before NaCl, significantly expedited the recovery of PD and R in a concentration-dependent manner; this effect was mimicked by posttreatment with ecabet and significantly mitigated by prior addition of indomethacin (1 x 10(-5) M) or N(G)-nitro-L-arginine methyl ester (L-NAME: 1 x 10(-3) M). The epithelial restitution was also significantly promoted by serosal application of either dmPGE(2) or NOR-3. The mucosal exposure to ecabet significantly increased the luminal release of PGE(2) and NO metabolites, the effects being attenuated by indomethacin and L-NAME, respectively. The mucous secretion was increased by ecabet as well as dmPGE(2) and NOR-3, and the effect of ecabet was significantly suppressed by both indomethacin and L-NAME. The inhibitory effects of L-NAME on the ecabet action were all significantly antagonized by concurrent addition of L-arginine. CONCLUSION: These results suggest that ecabet significantly expedited the restitution following gastric surface cell injury, and this action is mediated by endogenous NO as well as PGs and may be functionally associated with an increase of mucous secretion.

Abietanes↗

Chronic unilateral ureteral obstruction represented as renin-dependent hypertension.

A 50-year-old woman developed renin-dependent hypertension immediately after accidental unilateral ureteral ligation during hysterectomy, and the hypertension lasted for 5 months. Surgical release of the obstruction was carried out 157 days after the ligation. Then, her blood pressure was normalized. However, the obstructed kidney showed intensive tubulointerstitial fibrosis and functional recovery was not obtained. This case suggests that the renin-angiotensin system may be upregulated in human kidney during unilateral ureteral obstruction for a long duration.

Atrophy↗