22 results on '"Kurata, Y."'
Search Results
2. Subarachnoid-pleural fistula treated with noninvasive positive pressure ventilation: a two-case report and literature review.
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Kurata Y, Yoshimoto M, Takebayashi T, Kawaguchi S, Yamashita T, Kurata, Yoshiaki, Yoshimoto, Mitsunori, Takebayashi, Tsuneo, Kawaguchi, Satoshi, and Yamashita, Toshihiko
- Abstract
Study Design: A report on 2 cases of subarachnoid pleural fistula (SAPF) treated with noninvasive positive pressure ventilation (NPPV).Objective: To highlight the efficacy of NPPV in patients with SAPF.Summary Of Background Data: SAPF is a rare but distressing type of cerebrospinal fluid leakage. It is known to be a complication of anterior thoracic spine surgery. The pressure gradient between the subarachnoid space and the pleural cavity maintains the cerebrospinal fluid leakage and precludes the spontaneous closure of the dura. Surgical interventions such as primary repair, patch grafts, muscle flaps, and omental flaps have been advocated. Only limited reports were found with reference to NPPV applied to SAPF.Methods: Two patients, a 45-year-old woman and a 39-year-old woman, underwent anterior thoracic spine surgery to treat thoracic myelopathy caused by ossification of the posterior longitudinal ligament. After surgery, they developed SAPF due to perforation of the dura during surgery. Placement of thoracostomy tubes and subarachnoid drains had no effect and an NPPV device was applied.Results: During application of the NPPV device, 14 days in the first patient and 5 days in the second patient, the raised intrapleural pressure obstructed the fluid leakage and successfully treated the fistula. No recurrence of SAPF was observed after removal of the NPPV device and the patients avoided surgical interventions.Conclusion: SAPF is often resistant to conservative therapies and has been treated in an invasive manner. NPPV should be considered as an alternative before such interventions because it is effective, noninvasive, and safe. [ABSTRACT FROM AUTHOR]- Published
- 2010
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3. Diagnostic Accuracy of Magnetic Resonance Imaging for International Federation of Gynecology and Obstetrics 2018 IB to IIB Cervical Cancer Staging: Comparison Among Magnetic Resonance Sequences and Pathologies.
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Matsumoto YK, Kido A, Moribata Y, Chigusa Y, Himoto Y, Kurata Y, Otani S, Yajima R, Nishio N, Kuwahara R, Minamiguchi S, Mandai M, and Nakamoto Y
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- Cervix Uteri diagnostic imaging, Cervix Uteri pathology, Female, Humans, Middle Aged, Neoplasm Invasiveness, Neoplasm Staging, Reproducibility of Results, Societies, Medical, Magnetic Resonance Imaging methods, Uterine Cervical Neoplasms diagnostic imaging, Uterine Cervical Neoplasms pathology
- Abstract
Objective: This study aimed to investigate the most accurate magnetic resonance (MR) sequence for tumor detection, maximal tumor diameter, and parametrial invasion compared with histopathologic diagnoses., Methods: Fifty-one patients with International Federation of Gynecology and Obstetrics 2018 IB1 to IIB cervical cancer underwent preoperative MR imaging and surgical resection. Two radiologists independently evaluated the tumor detection, parametrial invasion, and tumor size in each of T2-weighted image, diffusion-weighted image, and contrast-enhanced T1-weighted image. Results obtained for squamous cell carcinoma (SCC) and adenocarcinoma were also compared., Results: Neither the tumor detection rate nor parametrial invasion was found to be significantly different among sequences. Tumor size assessment using MR imaging with pathology showed good correlation: r = 0.63-0.72. The adenocarcinoma size tended to be more underestimated than SCC in comparison with the pathologic specimen., Conclusions: Cervical cancer staging by MR images showed no significant difference among T2-weighted image, diffusion-weighted image, and contrast-enhanced T1-weighted image. Adenocarcinoma was prone to be measured as smaller than the pathologic specimen compared with SCC., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)
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- 2021
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4. Differences in Theophylline Clearance Between Patients With Chronic Hepatitis and Those With Liver Cirrhosis.
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Kurata Y, Muraki S, Kashihara Y, Hirota T, Araki H, and Ieiri I
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- Adult, Humans, Kinetics, Retrospective Studies, Hepatitis, Chronic metabolism, Liver Cirrhosis metabolism, Theophylline pharmacokinetics
- Abstract
Background: Theophylline, a xanthine derivative drug, is used for the treatment of respiratory diseases, such as asthma, and is primarily eliminated by hepatic metabolism. There is marked interindividual variability in theophylline clearance. Therefore, the aim of this study was to evaluate the influence of chronic hepatitis (CH), liver cirrhosis (LC), and other covariates on theophylline clearance by population pharmacokinetic (PPK) analysis., Methods: The authors retrospectively obtained 496 trough concentrations of theophylline at steady state from 226 adult patients with bronchial asthma. The liver functions of the patients were classified into 3 categories: normal hepatic function, CH, and LC. The PPK analysis was performed using the NONMEM program. CH, LC, age, smoking status, coadministration of clarithromycin (CAM), and sex were considered as covariates that affected theophylline clearance., Results: Theophylline clearance (CL/F per kg) was significantly influenced by CH, LC, smoking, and CAM. The final model of theophylline clearance was as follows: CL/F (L/h·kg) = 0.0484 × 1.40 × 0.861 × 0.889 × 0.557. Smoking is a well-known factor that markedly enhances CL/F through the induction of CYP1A enzymes, whereas CAM has been reported to inhibit CYP3A4. The final model for hepatic function showed that CL/F in CH and LC patients was 0.043 and 0.027 L/h/kg, respectively, and it was lower than that in patients with normal hepatic function. As theophylline clearance depends on intrinsic hepatic clearance, lower CL/F in patients with LC than in those with CH may be due to a decrease in the metabolic enzymatic capability of LC patients., Conclusions: Differences exist in theophylline clearance between CH and LC patients as per the PPK analysis.
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- 2020
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5. Hypoxia-inducible factor prolyl hydroxylase inhibitor in the treatment of anemia in chronic kidney disease.
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Kurata Y, Tanaka T, and Nangaku M
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- Erythropoietin metabolism, Humans, Hypoxia-Inducible Factor-Proline Dioxygenases metabolism, Iron metabolism, Anemia drug therapy, Anemia etiology, Hypoxia-Inducible Factor-Proline Dioxygenases antagonists & inhibitors, Prolyl-Hydroxylase Inhibitors therapeutic use, Renal Insufficiency, Chronic complications, Renal Insufficiency, Chronic drug therapy
- Abstract
Purpose of Review: Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) are orally active small molecules and are launched as novel therapeutic agents for anemia in chronic kidney disease (CKD). In contrast to conventional exogenous erythropoietin (EPO) administration, HIF-PHIs stimulate endogenous EPO production and improve iron metabolism via stabilization of hypoxia-inducible factor (HIF). This review summarizes the mechanism of action, the results of clinical trials, and future perspectives of HIF-PHIs., Recent Findings: Six HIF-PHIs are currently under phase III studies, some of which have been already completed. According to the results of clinical trials, HIF-PHIs increased and maintained hemoglobin levels in both nondialysis-dependent and dialysis-dependent CKD patients with physiological EPO concentrations. HIF-PHIs also improved iron utilization and were comparably effective regardless of underlying inflammation and iron status., Summary: HIF-PHIs have several advantages including oral administration, physiological EPO secretion, and improved iron utilization. Undoubtedly, HIF-PHIs will pave the new way in the field of treatment of anemia in CKD, but it should be noted that HIFs have pleiotropic effects on a plethora of cellular functions, which might lead to either beneficial or undesirable off-target effects. Intensive postmarketing surveillance is crucially important to identify unexpected consequences.
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- 2020
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6. Biphasic Renal Sympathetic Response to Hemorrhagic Hypotension in Mice.
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Zhang T, Tanida M, Uchida K, Suzuki Y, Yang W, Kuda Y, Kurata Y, Tominaga M, and Shibamoto T
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- Animals, Female, Heart Rate physiology, Hypotension physiopathology, Kidney metabolism, Kidney physiology, Male, Mice, Mice, Inbred C57BL, Sympathetic Nervous System physiopathology, TRPV Cation Channels metabolism, Vagotomy, Hypotension metabolism, Sympathetic Nervous System metabolism
- Abstract
Aim: The inhibitory responses of renal sympathetic nerve activity (RSNA) and heart rate (HR) to sustained hemorrhagic shock occurred in anesthetized rats, but have not yet been determined in mice. Here, we investigated the responses of RSNA and HR to hemorrhagic hypotension in anesthetized mice, with an emphasis on the molecule-based mechanism for roles of afferent vagal nerves., Methods: RSNA, HR, and mean systemic arterial pressure were continuously measured in male pentobarbital-anesthetized C57BL/6N mice. Hemorrhagic hypotension of 50 mmHg was evoked and maintained for 10 min., Results: During hemorrhagic hypotension, RSNA initially increased and then sustainedly decreased, while HR progressively decreased. Vagotomy eliminated the second-phase sympathoinhibition and bradycardia, and carotid sinus denervation with vagotomy abolished the initial renal sympathoexcitation. The renal sympathoinihibition during hemorrhagic hypotension of 50 mmHg was eliminated in mice pretreated with a transient receptor potential vanilloid type 1 channel (TRPV1) inhibitor, capsazepine, and in TRPV1 knockout (TRPV1) mice, but not in TRPV4 knockout mice. The bradycardia response to hemorrhagic hypotension was also absent in TRPV1 mice and mice pretreated with capsazepine., Conclusion: Hemorrhagic hypotension in anesthetized mice causes biphasic responses of RSNA with an initial increase, followed by a sustained decrease, and a progressive decrease in HR. The initial sympathoexcitation is mediated by carotid sinus baroreceptors, while the later sympathoinhibition and bradycardia are mediated via the TRPV1 signals of vagal afferents.
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- 2017
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7. Pulmonary vascular and airway responses to systemic vasoconstrictors in anesthetized BALB/c mice.
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Wang M, Shibamoto T, Shinomiya S, Yamamoto Y, Kurata Y, Kuda Y, Tanida M, and Toga H
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- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid pharmacology, Angiotensin II pharmacology, Animals, Blood Pressure drug effects, Cardiac Output drug effects, Dose-Response Relationship, Drug, Endothelin-1 pharmacology, Mice, Mice, Inbred BALB C, Pulmonary Circulation drug effects, Thromboxane A2 pharmacology, Vasopressins pharmacology, Airway Resistance drug effects, Vascular Resistance drug effects, Vasoconstriction drug effects, Vasoconstrictor Agents pharmacology
- Abstract
There is no systematic study in which the effects of vasoactive substances were investigated on pulmonary vascular resistance (PVR) in in vivo mouse by directly measuring cardiac output and the inflow and outflow pressures in the pulmonary circulation. We determined the responses of PVR, total peripheral resistance (TPR), and airway pressure (AWP) to angiotensin II, endothelin-1, vasopressin, phenylephrine, and thromboxane A2 analog U46619 in anesthetized BALB/c mice. Pulmonary arterial pressure, left atrial pressure (LAP), and aortic blood flow were measured. TPR increased dose-dependently in response to consecutive administration of all vasoconstrictors except vasopressin which reduced TPR at the highest dose of 100 nmol/kg. At high doses of vasoconstrictors, pulmonary arterial pressure and AWP increased due to increased LAP, as demonstrated by the separate LAP elevation experiments. When LAP transiently increased at high doses, PVR did not increase but decreased. Nonetheless, enodothelin-1, angiotensin II, and U46619 increased PVR. Vasopressin at 100 nmol/kg increased AWP without LAP elevation. In conclusion, the high doses of the vasoconstrictors studied here exert indirectly a transient pulmonary vasodilatory and AWP increasing actions due to pulmonary congestion evoked by strong systemic vasoconstriction. Nevertheless, enodothelin-1, angiotensin II, and U46619 cause pulmonary vasoconstriction, and vasopressin constricts airway in anesthetized BALB/c mice.
- Published
- 2015
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8. Pulmonary vasoconstrictive and bronchoconstrictive responses to anaphylaxis are weakened via β2-adrenoceptor activation by endogenous epinephrine in anesthetized rats.
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Zhang W, Shibamoto T, Kuda Y, Ohmukai C, and Kurata Y
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- Adrenalectomy, Adrenergic beta-1 Receptor Antagonists pharmacology, Adrenergic beta-2 Receptor Antagonists pharmacology, Animals, Aorta physiology, Blood Pressure physiology, Bronchoconstriction drug effects, Catecholamines blood, Central Venous Pressure drug effects, Central Venous Pressure physiology, Coronary Circulation drug effects, Coronary Circulation physiology, Epinephrine pharmacology, Heart physiology, Hemodynamics physiology, Male, Ovalbumin immunology, Portal Vein physiology, Pulmonary Artery drug effects, Pulmonary Artery physiology, Rats, Rats, Sprague-Dawley, Receptors, Adrenergic, beta-2 drug effects, Vascular Resistance physiology, Vasoconstriction drug effects, Anaphylaxis physiopathology, Anesthesia, Bronchoconstriction physiology, Epinephrine physiology, Receptors, Adrenergic, beta-2 physiology, Vasoconstriction physiology
- Abstract
Background: Patients treated with propranolol, a nonselective β-adrenoceptor antagonist, have increased incidence and severity of anaphylaxis. We determined whether β1- or β2-adrenoceptor antagonist modulated pulmonary vasoconstriction and bronchoconstriction in rat anaphylactic hypotension., Methods: Anesthetized ovalbumin-sensitized male Sprague-Dawley rats were randomly allocated to the following pretreatment groups (n = 7/group): (1) sensitized control (nonpretreatment), (2) propranolol, (3) the selective β2-adrenoceptor antagonist ICI 118,551, (4) the selective β1-adrenoceptor antagonist atenolol, and (5) adrenalectomy. Shock was induced by an intravenous injection of the antigen. Mean arterial pressure, pulmonary arterial pressure, left atrial pressure, central venous pressure, portal venous pressure, airway pressure, and aortic blood flow were continuously measured., Results: In either sensitized control or atenolol-pretreated rats, mean arterial pressure and aortic blood flow decreased substantially, whereas pulmonary arterial pressure and airway pressure did not increase soon after antigen injection. In contrast, in rats pretreated with either propranolol, ICI 118,551, or adrenalectomy, airway pressure significantly increased by 14 cm H2O, and pulmonary arterial pressure by 7.5 mmHg after antigen injection. At 2.5 min after antigen injection, the plasma concentration of epinephrine increased 14-fold in the sensitized rats except for the adrenalectomy group. Portal venous pressure after antigen injection increased by 16 mmHg similarly in all sensitized rats. All of the sensitized control group and two of the atenolol group were alive for 60 min after antigen injection, whereas all rats of the propranolol, ICI 118,551, and adrenalectomy groups died within 50 min after antigen injection., Conclusions: The pulmonary vasoconstrictive and bronchoconstrictive responses to systemic anaphylaxis were weakened via β2-adrenoceptor activation by epinephrine endogenously released from the adrenal gland in the anesthetized Sprague-Dawley rats.
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- 2011
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9. Reciprocal control of hERG stability by Hsp70 and Hsc70 with implication for restoration of LQT2 mutant stability.
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Li P, Ninomiya H, Kurata Y, Kato M, Miake J, Yamamoto Y, Igawa O, Nakai A, Higaki K, Toyoda F, Wu J, Horie M, Matsuura H, Yoshida A, Shirayoshi Y, Hiraoka M, and Hisatome I
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- Action Potentials physiology, Animals, Cell Membrane metabolism, Cells, Cultured, Disease Models, Animal, Electrophysiologic Techniques, Cardiac, Endoplasmic Reticulum metabolism, Ether-A-Go-Go Potassium Channels pharmacology, HEK293 Cells, Heat-Shock Response physiology, Humans, Mice, Myocytes, Cardiac drug effects, Myocytes, Cardiac metabolism, RNA, Small Interfering pharmacology, Ether-A-Go-Go Potassium Channels genetics, Ether-A-Go-Go Potassium Channels metabolism, HSC70 Heat-Shock Proteins metabolism, HSP70 Heat-Shock Proteins metabolism, Long QT Syndrome genetics, Long QT Syndrome metabolism, Mutation, Missense genetics
- Abstract
Rationale: The human ether-a-go-go-related gene (hERG) encodes the α subunit of the potassium current I(Kr). It is highly expressed in cardiomyocytes and its mutations cause long QT syndrome type 2. Heat shock protein (Hsp)70 is known to promote maturation of hERG. Hsp70 and heat shock cognate (Hsc70) 70 has been suggested to play a similar function. However, Hsc70 has recently been reported to counteract Hsp70., Objective: We investigated whether Hsc70 counteracts Hsp70 in the control of wild-type and mutant hERG stability., Methods and Results: Coexpression of Hsp70 with hERG in HEK293 cells suppressed hERG ubiquitination and increased the levels of both immature and mature forms of hERG. Immunocytochemistry revealed increased levels of hERG in the endoplasmic reticulum and on the cell surface. Electrophysiological studies showed increased I(Kr). All these effects of Hsp70 were abolished by Hsc70 coexpression. Heat shock treatment of HL-1 mouse cardiomyocytes induced endogenous Hsp70, switched mouse ERG associated with Hsc70 to Hsp70, increased I(Kr), and shortened action potential duration. Channels with disease-causing missense mutations in intracellular domains had a higher binding capacity to Hsc70 than wild-type channels and channels with mutations in the pore region. Knockdown of Hsc70 by small interfering RNA or heat shock prevented degradation of mutant hERG proteins with mutations in intracellular domains., Conclusions: These results indicate reciprocal control of hERG stability by Hsp70 and Hsc70. Hsc70 is a potential target in the treatment of LQT2 resulting from missense hERG mutations.
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- 2011
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10. Liver volume, as assessed by four ultrasonic crystals arranged to form a tetrahedron, decreases during anaphylactic shock in anesthetized rats.
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Takano H, Shibamoto T, Zhang W, and Kurata Y
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- Anaphylaxis physiopathology, Anesthesia, Animals, Liver blood supply, Male, Organ Size, Rats, Rats, Sprague-Dawley, Vasoconstriction physiology, Anaphylaxis pathology, Liver pathology, Ultrasonics
- Abstract
We determined the hepatic volume change in anaphylactic hypotension by using four ultrasonic crystals in anesthetized rats. The hepatic volume was measured with four ultrasonic crystals arranged to form a tetrahedron on the liver surface. Before in vivo experiments, using isolated perfused rat liver preparations, we compared the measured liver volume changes with the whole-liver weight changes during hepatic blood flow rate changes and venoconstriction induced by norepinephrine. The measured relative change of the tetrahedron volume (V[utc]; percentage changes of the initial volume) was closely correlated with the liver weight change (W; percentage changes of the initial liver weight): V(utc) = 0.85W - 4.11 (r² = 0.67). Then, we measured the liver weight and the tetrahedron volume during hepatic anaphylaxis in isolated perfused liver excised from the rats sensitized with ovalbumin. An injection of the antigen into the perfusate caused anaphylactic venoconstriction, liver weight loss (1.1 ± 0.3 g; 9% ± 1%), and the tetrahedron volume reduction (12% ± 4%). Finally, we measured the liver volume change during anaphylactic hypotension in anesthetized ovalbumin-sensitized rats. When the antigen was i.v. injected into anesthetized rats, along with systemic hypotension and hepatic venoconstriction, the liver tetrahedron volume decreased by 6% ± 2% from baseline. In conclusion, we established a method to measure the hepatic volume by using four ultrasonic crystals forming a tetrahedron. Using this ultrasonic crystal method, we demonstrated that liver volume decreases during anaphylactic hypotension in anesthetized rats.
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- 2010
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11. Mouse hepatic portal venoconstrictive response to vasoconstrictors is much weaker than that in rat.
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Zhao ZS, Shibamoto T, Tsutsumi M, Cui S, Zhang WM, Takano H, and Kurata Y
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- Actins biosynthesis, Angiotensin II pharmacology, Animals, Central Venous Pressure drug effects, Dose-Response Relationship, Drug, Endothelin-1 pharmacology, Immunohistochemistry, Liver blood supply, Liver drug effects, Liver metabolism, Male, Mice, Mice, Inbred BALB C, Muscle, Smooth blood supply, Muscle, Smooth drug effects, Muscle, Smooth metabolism, Norepinephrine pharmacology, Rats, Rats, Sprague-Dawley, Species Specificity, Portal Pressure drug effects, Vasoconstriction drug effects, Vasoconstrictor Agents pharmacology
- Abstract
We previously reported that the portal venous pressure (PPV) response of perfused mouse livers to various vasoactive agents was much weaker than that of other mammals such as rat, rabbit, and guinea pigs. The purpose of this study was to determine the responsiveness of PPV in in vivo BALB/c mouse to intraportal injections of the 3 major vasoconstrictors of angiotensin II, norepinephrine, and endothelin-1 in comparison with that in Sprague-Dawley rats. In anesthetized spontaneously breathing animals, PPV, systemic arterial pressure, and central venous pressure were directly and continuously measured. The above-mentioned vasoconstrictors were injected into the portal vein as a bolus repetitively at the doses ranging 0.01-100 nmol/kg. A dose-dependent increase in systemic arterial pressure in response to each vasoconstrictor was observed similarly in both mice and rats. All vasoconstrictors also caused a dose-dependent increase in PPV in both species, but the peak levels in mouse did not reach higher than 7 mm Hg, whereas it reached as high as 15-24 mm Hg in rats. Immunostaining for alpha-smooth muscle actin revealed that smooth muscles were distributed substantially in portal venules of rat but scarcely in that of mouse. In conclusion, PPV response to various vasoconstrictors was limited in anesthetized BALB/c mice, as compared with the anesthetized Sprague-Dawley rats, presumably due to small amount of vascular smooth muscle in mouse portal venules.
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- 2009
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12. Diagnostic features of sciatica without lumbar nerve root compression.
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Yoshimoto M, Kawaguchi S, Takebayashi T, Isogai S, Kurata Y, Nonaka S, Oki G, Kosukegawa I, and Yamashita T
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- Adult, Buttocks innervation, Buttocks pathology, Buttocks physiopathology, Female, Functional Laterality physiology, Genital Diseases, Female complications, Genitalia, Female pathology, Genitalia, Female physiopathology, Humans, Lumbar Vertebrae pathology, Lumbar Vertebrae physiopathology, Lumbosacral Plexus physiopathology, Magnetic Resonance Imaging, Male, Middle Aged, Muscle, Skeletal pathology, Muscle, Skeletal physiopathology, Predictive Value of Tests, Retrospective Studies, Sciatic Nerve physiopathology, Sciatica physiopathology, Severity of Illness Index, Sex Characteristics, Sex Distribution, Spinal Nerve Roots pathology, Spinal Nerve Roots physiopathology, Young Adult, Lumbosacral Plexus pathology, Sciatic Nerve pathology, Sciatica diagnosis, Sciatica etiology
- Abstract
Study Design: Retrospective case series review of patients showing sciatica without radiographic evidence of nerve root compression., Objective: To elucidate clinical features of sciatica caused by extralumbar spinal lesions., Summary of Background Data: Sciatica caused by extralumbar spinal lesions has been reported sporadically. Given the paucity of case series studies, however, the pathology and clinical features of such sciatica remain not fully understood., Methods: Sixty-one patients who presented with persistent sciatica were examined with lumbar magnetic resonance (MR) imaging. Of these, the records of patients showing no detectable nerve root compression in MR images were reviewed with respect to demographics, neurologic status, further diagnostic procedures, treatments, and treatment outcomes., Results: Of 61 patients, 10 (16.4%) showed sciatica and a lack of nerve root compression in the lumbar MR imaging. In demographics, there was female sex dominance (9 patients) and right side preference (9 patients). Eight patients exhibited sensory disturbance beyond a single dermatome. Piriformis syndrome was diagnosed in 3 patients and 5 patients were considered to have sacral plexus pathologies associated with gynecologic conditions such as ectopic endometriosis, ovarian cyst, and pregnancy. A review of the literature also supported the right side preference in sciatica associated with gynecologic conditions., Conclusions: Piriformis syndrome and gynecologic conditions account for most cases of extralumbar spinal sciatica. Female sex, right side involvement, and overlapping sensory disturbance are suggestive of extralumbar spinal sciatica associated with gynecologic conditions.
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- 2009
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13. 7-nitroindazole, but not L-NAME or aminoguanidine, attenuates anaphylactic hypotension in conscious rats.
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Zhang W, Shibamoto T, Cui S, Takano H, and Kurata Y
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- Animals, Antigens metabolism, Enzyme Inhibitors pharmacology, Male, Nitric Oxide Synthase Type II metabolism, Pressure, Rats, Rats, Sprague-Dawley, Time Factors, Anaphylaxis drug therapy, Guanidines pharmacology, Hypotension drug therapy, Indazoles pharmacology, NG-Nitroarginine Methyl Ester pharmacology, Shock drug therapy
- Abstract
The roles of NO and isozymes of NO synthase (NOS) are not known in anaphylactic hypotension of unanesthetized rats. Effects of inhibition of NOS, iNOS, and nNOS by N-nitro-L-arginine methyl ester (L-NAME), aminoguanidine, and 7-nitroindazole, respectively, were determined on the antigen-induced systemic hypotension and portal hypertension in conscious Sprague-Dawley rats sensitized with the ovalbumin antigen. The MAP and portal venous pressure were directly and simultaneously measured. The control rats showed a decrease in MAP along with an increase in portal venous pressure but did not die within 48 h after antigen injection. In the rats pretreated with the nonselective NOS inhibitor L-NAME (10 mg/kg), MAP before and after antigen administration was significantly higher than that of the control rats, but the net decrease in MAP and increase in portal venous pressure were rather greater than those of the control, resulting in fatal outcome within 12 h after antigen administration. In contrast, pretreatment with the relatively selective nNOS inhibitor 7-nitroindazole (50 mg/kg) substantially attenuated anaphylactic hypotension over 20 min after antigen administration, whereas the relatively selective iNOS inhibitor aminoguanidine (100 mg/kg) did not affect it. In conclusion, in anaphylactic hypotension of unanesthetized rats, NO derived from nNOS, but not from iNOS, may be involved, and the nonselective NOS inhibitor L-NAME is lethal.
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- 2009
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14. Venous resistance increases during rat anaphylactic shock.
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Cui S, Shibamoto T, Zhang W, Takano H, and Kurata Y
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- Anaphylaxis chemically induced, Animals, Dogs, Hypotension chemically induced, Hypotension physiopathology, Male, Rats, Rats, Sprague-Dawley, Anaphylaxis physiopathology, Blood Pressure, Portal Vein physiopathology, Vascular Resistance
- Abstract
Anaphylactic shock is a sudden, life-threatening allergic reaction associated with severe hypotension. The increased venous resistance accounts for the anaphylactic hypotension in anesthetized dogs. However, the change in peripheral vascular resistances during anaphylactic hypotension in other animals such as rats is not known. We measured the mean circulatory filling pressure using the mechanical occlusion method of inflation of the right atrial balloon along with systemic arterial pressure (Psa), central venous pressure, and portal venous pressure. Cardiac output was also measured with the thermodilution method. From these hemodynamic variables, we calculated the total peripheral and venous (Rv) resistances during anaphylactic hypotension in anesthetized rats. These hemodynamic variables were compared with those in the hemorrhagic shock. After an intravenous injection of 0.6 mg antigen ovalbumin in sensitized rats, Psa decreased from 119 +/- 4 to 43 +/- 2 mmHg, cardiac output decreased from 84.5 +/- 5.7 to 37.8 +/- 2.1 mL min, central venous pressure decreased from 0.9 +/- 0.1 to 0.1 +/- 0.1 mmHg, and mean circulatory filling pressure also decreased from 6.0 +/- 0.2 to 5.2 +/- 0.3 mmHg. Thus, the Rv increased from 0.06 +/- 0.05 to 0.15 +/- 0.02 mmHg mL(-1) min(-1), but total peripheral resistance did not significantly change. Portal venous pressure also increased from 5.6 +/- 0.5 to 21.5 +/- 0.9 mmHg. Hematocrit markedly increased from the baseline values of 43% +/- 1% to 55% +/- 1% at 15 min after antigen. During hemorrhagic shock, Psa decreased in the manner similar to anaphylactic shock; however, Rv did not significantly change, and portal venous pressure decreased. In conclusion, in rat anaphylactic shock, a substantial increase in Rv presumably due to hepatic venoconstriction may decrease venous return, resulting in systemic hypotension.
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- 2008
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15. Oxygen consumption, assessed with the oxygen absorption spectrophotometer, decreases independently of venoconstriction during hepatic anaphylaxis in perfused rat liver.
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Cui S, Shibamoto T, Ruan Z, Takano H, Liu W, and Kurata Y
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- Anaphylaxis chemically induced, Anaphylaxis pathology, Animals, In Vitro Techniques, Liver blood supply, Liver pathology, Male, Nitroprusside pharmacology, Norepinephrine pharmacology, Perfusion, Rats, Spectrophotometry, Vasoconstrictor Agents pharmacology, Vasodilator Agents pharmacology, Anaphylaxis metabolism, Liver metabolism, Oxygen Consumption drug effects, Vasoconstriction drug effects
- Abstract
Anaphylactic shock is accompanied by a decrease in oxygen consumption. However, it is not well known whether oxygen consumption decreases during local anaphylactic reaction in liver. We determined the effects of anaphylaxis and norepinephrine on oxygen consumption in isolated rat livers perfused portally and recirculatingly at constant flow with blood (hematocrit, 12%). Oxygen consumption was continuously measured by monitoring the portal-hepatic venous oxygen saturation differences using the absorption spectrophotometer, the probes of which were built in perfusion lines. Hepatic anaphylaxis was induced by an injection of ovalbumin (0.01 or 0.1 mg) into the perfusate of the isolated liver of the rat sensitized with subcutaneous ovalbumin (1 mg). Hepatic venoconstriction and liver weight loss were similarly observed in response to norepinephrine (0.01-10 micromol L(-1)) and anaphylaxis. However, hepatic anaphylaxis reduced oxygen consumption, whereas norepinephrine increased it. There was a possibility that anaphylactic venoconstriction could reduce the perfused surface area, resulting in decreased oxygen consumption. However, pretreatment with a vasodilator of sodium nitroprusside substantially attenuated venoconstriction but not the decrease in oxygen consumption during anaphylaxis. Thus, we conclude that local hepatic anaphylaxis decreases oxygen consumption independently of venoconstriction in isolated blood-perfused rat livers.
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- 2006
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16. Effects of Hct on L-NAME-induced potentiation of anaphylactic presinusoidal constriction in perfused rat livers.
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Cui S, Shibamoto T, Liu W, Takano H, Zhao ZS, and Kurata Y
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- Anaphylaxis chemically induced, Anaphylaxis immunology, Animals, Drug Synergism, Enzyme Inhibitors chemistry, Enzyme Inhibitors pharmacology, Liver blood supply, Liver drug effects, Liver metabolism, Liver physiopathology, Male, NG-Nitroarginine Methyl Ester chemistry, Ovalbumin administration & dosage, Ovalbumin immunology, Perfusion methods, Portal Pressure drug effects, Rats, Rats, Sprague-Dawley, Stereoisomerism, Vascular Resistance drug effects, Vasoconstriction drug effects, Vasoconstriction immunology, Viscosity, Anaphylaxis physiopathology, Hematocrit, Liver Circulation drug effects, NG-Nitroarginine Methyl Ester pharmacology
- Abstract
Effects of hematocrit (Hct) on N-nitro-L-arginine methyl ester (L-NAME)-induced modulation of anaphylactic venoconstriction were determined in isolated perfused rat livers. The rats were sensitized with ovalbumin (1 mg), and the livers were excised 2 weeks later and perfused portally and recirculatingly under constant flow at Hct of 0%, 5%, 16%, and 22%. The hepatic sinusoidal pressure was estimated via the double occlusion pressure (Pdo), and the presinusoidal resistance (Rpre) and the postsinusoidal resistance (Rhv) were calculated. The antigen of ovalbumin 0.1 mg was injected into the reservoir at 10 minutes after pretreatment with L-NAME (100 microM) or D-NAME (100 microM). Perfusate viscosity, a determinant of vascular resistance and shear stress, was increased in parallel with Hct. In the D-NAME groups, antigen caused predominant presinusoidal constriction. The magnitude of venoconstriction was significantly smaller at Hct 0% than at Hct 5% to 22%, whereas no significant differences were found among Hct 5% to 22%. L-NAME potentiated the antigen-induced increase in Rpre, but not in Rpost at Hct 5% to 22% as compared with D-NAME. But the augmentative effects of L-NAME were similar in magnitude among Hct 5% to 22%. These findings suggest that hepatic anaphylaxis increases production of nitric oxide, which consequently attenuates anaphylactic presinusoidal constriction in rat livers, and that these effects are independent of perfusate Hct or viscosity in blood-perfused rat livers.
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- 2006
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17. Adiponectin acts as an endogenous antithrombotic factor.
- Author
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Kato H, Kashiwagi H, Shiraga M, Tadokoro S, Kamae T, Ujiie H, Honda S, Miyata S, Ijiri Y, Yamamoto J, Maeda N, Funahashi T, Kurata Y, Shimomura I, Tomiyama Y, and Kanakura Y
- Subjects
- Adenoviridae genetics, Adiponectin deficiency, Animals, Atherosclerosis genetics, Atherosclerosis metabolism, Blood Platelets physiology, Carotid Artery Injuries genetics, Collagen, Integrin alpha2 metabolism, Integrin beta3 metabolism, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, P-Selectin metabolism, Platelet Count, Pulsatile Flow, Receptors, Adiponectin, Receptors, Cell Surface genetics, Thrombosis genetics, Adiponectin genetics, Adiponectin metabolism, Carotid Artery Injuries metabolism, Platelet Aggregation physiology, Thrombosis metabolism
- Abstract
Objective: Obesity is a common risk factor in insulin resistance and cardiovascular diseases. Although hypoadiponectinemia is associated with obesity-related metabolic and vascular diseases, the role of adiponectin in thrombosis remains elusive., Methods and Results: We investigated platelet thrombus formation in adiponectin knockout (APN-KO) male mice (8 to 12 weeks old) fed on a normal diet. There was no significant difference in platelet counts or coagulation parameters between wild-type (WT) and APN-KO mice. However, APN-KO mice showed an accelerated thrombus formation on carotid arterial injury with a He-Ne laser (total thrombus volume: 13.36+/-4.25 x 10(7) arbitrary units for APN-KO and 6.74+/-2.87x10(7) arbitrary units for WT; n=10; P<0.01). Adenovirus-mediated supplementation of adiponectin attenuated the enhanced thrombus formation. In vitro thrombus formation on a type I collagen at a shear rate of 250 s(-1), as well as platelet aggregation induced by low concentrations of agonists, was enhanced in APN-KO mice, and recombinant adiponectin inhibited the enhanced platelet aggregation. In WT mice, adenovirus-mediated overexpression of adiponectin additionally attenuated thrombus formation., Conclusions: Adiponectin deficiency leads to enhanced thrombus formation and platelet aggregation. The present study reveals a new role of adiponectin as an endogenous antithrombotic factor.
- Published
- 2006
- Full Text
- View/download PDF
18. Oxidized LDL increases and interferon-gamma decreases expression of CD36 in human monocyte-derived macrophages.
- Author
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Nakagawa T, Nozaki S, Nishida M, Yakub JM, Tomiyama Y, Nakata A, Matsumoto K, Funahashi T, Kameda-Takemura K, Kurata Y, Yamashita S, and Matsuzawa Y
- Subjects
- CD36 Antigens metabolism, Cell Differentiation drug effects, Cells, Cultured, Cytokines pharmacology, Enzyme-Linked Immunosorbent Assay methods, Flow Cytometry, Fluorescent Antibody Technique, Gene Expression Regulation, Humans, Immunohistochemistry, Lipoproteins, LDL isolation & purification, Macrophages cytology, Macrophages metabolism, Monocytes cytology, Monocytes metabolism, Oxidation-Reduction, CD36 Antigens drug effects, Interferon-gamma pharmacology, Lipoproteins, LDL pharmacology, Macrophages drug effects, Monocytes drug effects
- Abstract
CD36 is a glycoprotein with an Mr of 88 kDa that is expressed on platelets, monocytes/macrophages, capillary endothelial cells, and adipocytes. We previously demonstrated that CD36 is involved in the uptake of oxidized low density lipoprotein (OxLDL) by using CD36-deficient macrophages (J Clin Invest. 1995;96:1859). However, the regulation of CD36 expression in human monocyte-derived macrophages has not been fully elucidated. The current study attempted to clarify the effect of OxLDL and cytokines, both of which are present in atherosclerotic lesions and may play an important role in atherogenesis, on the expression of CD36. A cell enzyme-linked immunosorbent assay and flow cytometry were used to detect CD36 protein. A ribonuclease protection assay was used to measure CD36 mRNA in human monocyte-derived macrophages. The expression of CD36 was increased during the differentiation of monocytes to macrophages. Incubation of macrophages with 25 microg/mL OxLDL for 24 hours increased the level of CD36 protein by 56% and that of CD36 mRNA by 58%. Lysophosphatidylcholine did not affect the expression of CD36. The effects of OxLDL were demonstrated in macrophages that had already differentiated to the point where CD36 expression was almost maximal. Interferon-gamma (IFN-gamma) reduced the expression of CD36 in a dose-dependent manner. A concentration of 1000 U/mL IFN-gamma significantly reduced the expression of CD36 protein by 57% and that of CD36 mRNA by 30%. In conclusion, CD36 may be important in the formation of foam cells by induction through its ligand (OxLDL). Moreover, some local factors, such as IFN-gamma, may suppress CD36 expression on macrophages in human atherosclerotic lesions.
- Published
- 1998
- Full Text
- View/download PDF
19. Vitrectomy for diabetic retinopathy in patients undergoing hemodialysis for associated end-stage renal failure.
- Author
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Hayashi H, Kurata Y, Imanaga Y, Goya K, and Oshima K
- Subjects
- Diabetic Retinopathy complications, Diabetic Retinopathy physiopathology, Female, Glaucoma, Neovascular etiology, Humans, Kidney Failure, Chronic complications, Male, Middle Aged, Postoperative Complications, Postoperative Period, Retinal Detachment etiology, Retinal Hemorrhage etiology, Retrospective Studies, Visual Acuity physiology, Diabetic Retinopathy surgery, Kidney Failure, Chronic therapy, Renal Dialysis, Vitrectomy
- Abstract
Purpose: Candidates for diabetic vitrectomy often have concurrent renal dysfunction and have undergone hemodialysis. The influence of hemodialysis on the surgical outcome of vitrectomy was investigated., Methods: Vitrectomy was performed on 76 eyes with proliferative diabetic retinopathy in 66 patients with end-stage renal failure who had undergone hemodialysis. Follow-up was longer than 1 year., Results: No uncontrollable hemorrhage occurred either during or immediately after the surgery. Final visual acuity after surgery was the same as preoperative visual acuity in 31.5% of the eyes; improvement was seen in 60.5% of the eyes. A final visual acuity of 0.2 or better was observed in 57.6% of the eyes. Major postoperative complications included recurrent vitreous hemorrhage, rhegmatogenous retinal detachment, fibrin clot formation, neovascular glaucoma, flat anterior chamber, and a transient rise in intraocular pressure., Conclusion: Renal failure and hemodialysis do not appear to have a deteriorative influence on the outcome of vitrectomy for proliferative diabetic retinopathy. A flat anterior chamber seems to be a rare and perhaps unique postoperative complication of gas-filled eyes in patients who have undergone hemodialysis.
- Published
- 1998
- Full Text
- View/download PDF
20. A single nucleotide insertion in codon 317 of the CD36 gene leads to CD36 deficiency.
- Author
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Kashiwagi H, Tomiyama Y, Nozaki S, Honda S, Kosugi S, Shiraga M, Nakagawa T, Nagao N, Kanakura Y, Kurata Y, and Matsuzawa Y
- Subjects
- Base Sequence, Blood Platelets metabolism, DNA, Complementary genetics, Female, Heterozygote, Humans, Macrophages metabolism, Molecular Sequence Data, RNA, Messenger genetics, Sequence Deletion, Thrombocytopenia blood, Thrombocytopenia genetics, CD36 Antigens genetics, Codon genetics, Frameshift Mutation
- Abstract
CD36 is a multifunctional integral-membrane glycoprotein that acts as a receptor for thrombospondin, collagen, long-chain fatty acids, and oxidized LDL. Platelet CD36 deficiency can be divided into two groups. In type I, neither platelets nor monocytes/macrophages express CD36; in type II, monocytes/macrophages express CD36 but platelets do not. Two known mutations cause CD36 deficiency, ie, a 478C-->T substitution in codon 90 (proline90-->serine) and a dinucleotide deletion at nucleotide 539 in codon 110. In this study we investigated a type I Japanese subject (A.T.) and identified a new mutation, a single nucleotide insertion at nucleotide 1159 in codon 317. This mutation leads to a frameshift and the appearance of a premature stop codon. CD36 gene analysis indicated that A.T. was a compound heterozygote for a dinucleotide deletion at nucleotide 539 and the single nucleotide insertion at nucleotide 1159. RNase protection studies suggested that the new mutation as well as the dinucleotide deletion led to a marked reduction in the level of CD36 mRNA in her macrophages. However, the new mutation could be detected in macrophage but not platelet CD36 mRNA. These data suggest that the allele having the single nucleotide insertion in this subject has an additional abnormality that results in the absence of the mutated CD36 mRNA in platelets.
- Published
- 1996
- Full Text
- View/download PDF
21. Ball-and-socket ankle joint: anatomical and kinematic analysis of the hindfoot.
- Author
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Hiroshima K, Kurata Y, Nakamura M, and Ono K
- Subjects
- Child, Child, Preschool, Female, Femur abnormalities, Foot surgery, Humans, Infant, Infant, Newborn, Leg Length Inequality etiology, Male, Movement, Tibia abnormalities, Ankle Joint abnormalities, Foot Deformities, Congenital, Heel abnormalities
- Abstract
Ten feet in eight children with ball-and-socket ankle joint (BSA-J) are reported with discussion of associated anomalies, kinematic analysis of the hindfoot motion, and talocalcaneal malalignment in the apparent valgus deformities. BSA-J is considered to be a common congenital condition associated with other anomalies in the foot or lower extremities. Even though BSA-J seems to have unusual side-to-side motion at the ankle joint, it does not occur in patients without subtalar fusion. Moreover, apparently valgus feet are responsible for talocalcaneal malalignment, not for lateral unstable motion at the ankle.
- Published
- 1984
22. Electrophysiological effects of maprotiline, a tetracyclic antidepressant agent, on isolated cardiac preparations.
- Author
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Igawa O, Kotake H, Kurata Y, Saitoh M, Fujimoto Y, Hasegawa J, and Mashiba H
- Subjects
- Action Potentials drug effects, Animals, Guinea Pigs, In Vitro Techniques, Membrane Potentials drug effects, Papillary Muscles drug effects, Rabbits, Sinoatrial Node drug effects, Anthracenes pharmacology, Heart drug effects, Maprotiline pharmacology
- Abstract
We studied the effects of maprotiline, a tetracyclic antidepressant agent, on transmembrane potentials recorded from papillary muscles of guinea pigs and sinoatrial nodes of rabbits, using standard microelectrode techniques. Maprotiline (10-100 microM) produced dose-dependent decreases in the maximum rate of rise (Vmax) and action potential duration in papillary muscles, while the resting potential (Em) was not significantly affected. Maprotiline also shifted the Vmax-Em relation to more negative potentials. The slow action potentials of papillary muscles elicited by high [K+]o were also depressed by the drug application. In sinoatrial node cells, maprotiline (above 10 microM) reduced heart rate, Vmax, and action potential amplitude, and increased the action potential duration at half-amplitude. The slope of the phase 4 depolarization was decelerated by the drug. These results suggest that maprotiline depresses not only the fast inward sodium current but also the slow inward calcium current, and that relatively high concentrations of maprotiline exert an inhibitory effect on the electrical activity of the fast- and slow-response fibers of the hearts.
- Published
- 1988
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