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1.
J Pharmacol Sci ; 154(3): 218-224, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38395523

RESUMO

An injectable anti-influenza drug peramivir has been reported to induce QT-interval prolongation in some phase III studies, although its thorough QT/QTc study was negative. We investigated the discrepancy among those clinical studies using isoflurane-anesthetized beagle dogs (n = 4). Peramivir in doses of 1 mg/kg/10 min (sub-therapeutic dose) followed by 10 mg/kg/10 min (clinically-relevant dose) was intravenously administered. Peramivir prolonged QT interval/QTcV and Tpeak-Tend, and tended to delay ventricular repolarization in a reverse-frequency dependent manner, indicating IKr inhibition in vivo. Meanwhile, peramivir did not alter P-wave duration, PR interval or QRS width, indicating a lack of impact on cardiac conduction via Na+ or Ca2+ channel inhibition in vivo. Peramivir prolonged Tpeak-Tend and tended to prolong terminal repolarization period, which would develop substrates for initiating and maintaining spiral reentry, respectively. Meanwhile, peramivir did not prolong J-Tpeakc, which could not induce early afterdepolarization, a trigger inducing torsade de pointes. Thus, our results support that clinical dose exposure of peramivir can delay the ventricular repolarization in influenza patients. Peramivir has only a small potential to induce torsade de pointes in patients with the intact hearts, but caution should be paid on its use for patients formerly having the trigger for torsade de pointes.


Assuntos
Ácidos Carbocíclicos , Guanidinas , Influenza Humana , Isoflurano , Síndrome do QT Longo , Torsades de Pointes , Humanos , Cães , Animais , Isoflurano/efeitos adversos , Influenza Humana/tratamento farmacológico , Coração/fisiologia , Síndrome do QT Longo/induzido quimicamente , Eletrocardiografia
2.
J Pharmacol Sci ; 154(4): 294-300, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38485347

RESUMO

Cardio-stimulatory actions of aciclovir have been considered to primarily depend on the sympathetically-mediated reflex resulting from its hypotensive effect. To further clarify onset mechanisms of the cardio-stimulatory actions, we initially studied them using isoflurane-anesthetized dogs under thorough ß1-adrenoceptor blockade with atenolol (1 mg/kg, i.v.) (n = 4). Aciclovir (20 mg/kg/10 min, i.v.) decreased mean arterial blood pressure by 10 mmHg, whereas it increased heart rate by 10 bpm and maximum upstroke velocity of ventricular pressure by 928 mmHg/s, and shortened AH interval by 2 ms, indicating that cardio-stimulatory actions were not totally abolished by ß1-adrenoceptor blockade. Then, unknown mechanisms of cardio-stimulatory action were explored. Since aciclovir has a similar chemical structure to theophylline, in silico molecular docking simulation was performed, indicating aciclovir as well as theophylline possesses strong likelihood of interactions with phosphodiesterase 1A, 1C and 3A. Indeed, aciclovir inhibited phosphodiesterase 1A derived from the bovine heart (n = 4), moreover it exerted positive chronotropic action on the atrial tissue preparation of rats along with an increase of tissue cyclic AMP concentration (n = 4). These results indicate that cardio-stimulatory actions of aciclovir could result from not only hypotension-induced, reflex-mediated increase of sympathetic tone but also its inhibitory effects on phosphodiesterase in the heart.


Assuntos
Hipotensão , Teofilina , Animais , Bovinos , Ratos , Cães , Teofilina/farmacologia , Aciclovir/farmacologia , Simulação de Acoplamento Molecular , Pressão Sanguínea , Átrios do Coração , Frequência Cardíaca , Diester Fosfórico Hidrolases , Receptores Adrenérgicos
3.
J Pharmacol Sci ; 152(4): 201-209, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37344055

RESUMO

We simultaneously assessed electropharmacological effects of anti-atrial fibrillatory drug vernakalant and its potential risk toward torsade de pointes. Vernakalant hydrochloride in doses of 0.3 and 3 mg/kg/10 min was intravenously administered to isoflurane-anesthetized beagle dogs without (n = 5) and with (n = 4) α-adrenoceptor blockade. Its vascular effect was analyzed using the rat aortae (n = 12). Vernakalant increased total peripheral vascular resistance and preload to left ventricle, leading to transient elevation of mean blood pressure indirectly via non-adrenergic pathway. Vernakalant suppressed sinus automaticity, ventricular contractility and intra-atrial/atrioventricular nodal/intraventricular conductions, and decreased cardiac output. Moreover, vernakalant prolonged atrial/ventricular effective refractory period by 53/55 ms, respectively, whereas it delayed ventricular repolarization in a reverse frequency-dependent manner. The extent of prolongation in early/late ventricular repolarization and electrically vulnerable period was 26/32 and 9 ms, respectively when QT-interval prolongation was the greatest. We compared them with those of known anti-atrial fibrillatory drugs; ranolazine, amiodarone, dronedarone, dl-sotalol and bepridil. The magnitude of vernakalant to alter those variables was the greater among those drugs except that the atrial selectivity was the lesser of those. Thus, vernakalant is expected to be efficacious against atrial fibrillation, but caution should be excised on its use for patients having labile ventricular function and repolarization.


Assuntos
Fibrilação Atrial , Isoflurano , Torsades de Pointes , Cães , Animais , Ratos , Fibrilação Atrial/tratamento farmacológico , Torsades de Pointes/induzido quimicamente , Isoflurano/efeitos adversos , Antiarrítmicos/farmacologia
4.
Esophagus ; 20(1): 63-71, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36042126

RESUMO

BACKGROUND: Anastomotic leakage of cervical esophagogastrostomy following radical esophagectomy for esophageal cancer has reduced over time; however, postoperative anastomotic stricture still occurs at a considerably high rate. We developed a novel method of circular-stapled esophagogastrostomy by employing the keyhole procedure, which uses a linear stapler to enlarge the anastomotic opening made with a circular stapler (CS). METHODS: We retrospectively reviewed 70 patients with esophageal cancer who underwent transthoracic esophagectomy and reconstruction via cervical CS-mediated anastomosis with or without the keyhole procedure between 2018 and 2020. The primary outcome was postoperative anastomotic stricture incidence within 180 days after surgery. RESULTS: Among 70 patients, 22 underwent the keyhole procedure (CS + K group) and the remaining did not (CS group). No differences were observed in patients' age, sex, body mass index, performance status, American Society of Anesthesiologists physical status, Charlson's comorbidity index, tumor histological type, tumor location, clinical stage, or preoperative treatment. A smaller stapler was used in the CS + K group (p < 0.001). Incidence of anastomotic stricture was significantly different (CS vs. CS + K, 18.8 vs. 0%, p = 0.049), especially when a 21 or 23 mm CS was used (CS vs. CS + K, 50.0 vs. 0%, p = 0.005). Univariate analysis confirmed that CS ≤ 23 without keyhole was a significant risk factor (p = 0.001). CONCLUSIONS: The keyhole procedure could be a simple and useful alternative technique that reduces the risk of stricture formation in cervical esophagogastric anastomosis, especially when using the smaller-sized CS.


Assuntos
Neoplasias Esofágicas , Esofagectomia , Humanos , Esofagectomia/efeitos adversos , Esofagectomia/métodos , Constrição Patológica/etiologia , Constrição Patológica/cirurgia , Estudos Retrospectivos , Grampeamento Cirúrgico/efeitos adversos , Grampeamento Cirúrgico/métodos , Neoplasias Esofágicas/patologia , Complicações Pós-Operatórias/etiologia
5.
J Pharmacol Sci ; 149(4): 175-178, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35717070

RESUMO

Since information is still limited whether atrial IK,ACh may become a potential therapeutic target to terminate persistent atrial fibrillation (AF), we assessed it by using the persistent AF canine model with representative IK,ACh inhibitor AVE0118 and class I drugs. AVE0118 (6 mg/kg, n = 7), disopyramide (3 mg/kg, n = 7) and cibenzoline (3 mg/kg, n = 6) terminated the AF in 3/7, 1/7 and 2/6 animals, respectively, whereas aprindine (3 mg/kg, n = 6) did not suppress it. These findings suggest that IK,ACh inhibition in addition to open-state INa suppression with slow dissociation kinetics can synergistically exert potent antiarrhythmic action against persistent AF.


Assuntos
Fibrilação Atrial , Potenciais de Ação , Animais , Antiarrítmicos/farmacologia , Antiarrítmicos/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Compostos de Bifenilo , Cães , Átrios do Coração
6.
J Pharmacol Sci ; 148(4): 343-350, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35300808

RESUMO

Although NMDA receptor antagonist memantine is considered to be better tolerated than cholinesterase inhibitors on treating Alzheimer's disease, several types of cardiovascular adverse events have been associated with memantine treatment, including hypertension, myocardial infarction, severe bradycardia and QT-interval prolongation. In order to clarify how memantine induces these cardiovascular adverse events, we assessed its electropharmacological effects using the halothane-anesthetized dogs (n = 4). Memantine hydrochloride was intravenously administered in doses of 0.01, 0.1 and 1 mg/kg over 10 min, providing subtherapeutic, clinically-relevant and supratherapeutic concentrations, respectively. The low to high doses increased the mean blood pressure and left ventricular contraction and enhanced the atrioventricular nodal conduction, suggesting an increase of sympathicotonic output from the central nervous system similarly to donepezil, which might induce myocardial ischemia in patients with coronary artery disease. Meanwhile, the high dose suppressed the intra-atrial conduction and the low to high doses inhibited the intra-ventricular conduction, indicating potential to induce severe bradycardic adverse event by advanced cardiac conduction block in susceptible patients. Memantine alone did not induce repolarization delay, indicating lack of risk for inducing torsade de pointes. Thus, these in vivo experimental findings may provide basic information to better understand the clinically observed adverse events of memantine.


Assuntos
Halotano , Síndrome do QT Longo , Animais , Arritmias Cardíacas/induzido quimicamente , Cães , Halotano/efeitos adversos , Ventrículos do Coração , Humanos , Síndrome do QT Longo/induzido quimicamente , Memantina/efeitos adversos
7.
J Pharmacol Sci ; 150(3): 154-162, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36184120

RESUMO

Imatinib has been reported to induce heart failure and/or QTc prolongation. To better understand their underlying mechanisms, we assessed its effects on cardiohemodynamic, electrocardiographic and echocardiographic variables along with biomarkers of myocardial damage. Imatinib mesylate in doses of 1 and 10 mg/kg was intravenously administered to the halothane-anesthetized beagle dogs (n = 4). Effects of imatinib on each phase of isovolumetric contraction, ejection, isovolumetric relaxation and filling were studied, whereas its electrophysiological effects on early and late repolarization were analyzed by measuring J-Tpeak and Tpeak-Tend, respectively. The low and high doses of imatinib provided peak plasma concentrations of 3.23 and 17.39 µg/mL, reflecting clinically-relevant and supratherapeutic concentrations, respectively. Neither lethal ventricular tachyarrhythmia nor cardiohemodynamic collapse was observed. Imatinib decreased amplitude of peak -dP/dt, indicating suppression of isovolumetric relaxation, whereas no significant change was detected in the other phases. Imatinib prolonged QTc and J-Tpeakc without altering Tpeak-Tend, indicating increase of net inward current, which leads to intracellular Ca2+ overload. Thus, imatinib suppressed ventricular active relaxation and early repolarization, which may suggest the association of mitochondrial dysfunction-associated inhibition of ATP production. Since those findings were also reported for dasatinib, sunitinib and lapatinib, they could be common cardiac phenotype of tyrosine kinase inhibitors in vivo.


Assuntos
Halotano , Inibidores de Proteínas Quinases , Trifosfato de Adenosina , Animais , Biomarcadores , Dasatinibe , Cães , Halotano/farmacologia , Mesilato de Imatinib/farmacologia , Lapatinib , Inibidores de Proteínas Quinases/efeitos adversos , Sunitinibe
8.
J Pharmacol Sci ; 150(3): 191-199, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36184124

RESUMO

We investigated how a lack of placebo control affects the interpretation of results of thorough QT/QTc (TQT) study. Results of TQT study in 48 healthy Japanese subjects assessing the effects of 480 and 960 mg of carotegrast methyl (test drug) and 400 mg of moxifloxacin (positive control) on the time-matched changes in corrected QT from baseline (ΔQTcF) and the placebo-adjusted ΔQTcF (ΔΔQTcF) were analyzed with central-tendency and concentration-response analyses. In central-tendency analysis, moxifloxacin prolonged ΔQTcF and ΔΔQTcF with the largest mean values (90% confidence interval) of 12.1 ms (9.3, 14.8) and 15.4 ms (12.6, 18.1), respectively. Meanwhile, carotegrast methyl hardly altered ΔQTcF and ΔΔQTcF with the largest mean values of 0.8 ms (-2.3, 3.9) and 2.1 ms (-0.7, 4.8) for the low dose, and -0.2 ms (-3.4, 3.0) and 1.6 ms (-0.9, 4.2) for the high dose, respectively. In concentration-response analysis, moxifloxacin attained the estimated mean values for ΔQTcF and ΔΔQTcF of 11.4 ms (8.5, 14.4) and 16.7 ms (14.0, 19.4) at the mean Cmax, whereas carotegrast methyl provided those of -4.6 ms (-7.3, -1.9) and 0.7 ms (-1.4, 2.8), respectively. Thus, lack of placebo control did not influence the interpretation of TQT study with either of the analysis in line with updated E14/S7B Q&As.


Assuntos
Fluoroquinolonas , Síndrome do QT Longo , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Eletrocardiografia , Voluntários Saudáveis , Frequência Cardíaca , Humanos , Integrina alfa4/farmacologia , Japão , Moxifloxacina/farmacologia , Fenilalanina/análogos & derivados , Quinazolinonas
9.
J Pharmacol Sci ; 148(1): 179-186, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34924124

RESUMO

Since information of antiviral drug oseltamivir on the anti-atrial fibrillation (AF) property is still limited, we assessed it using the canine paroxysmal AF model. Oseltamivir in doses of 3 and 30 mg/kg/10 min was intravenously infused to the isoflurane-anesthetized, chronic atrioventricular block dogs (n = 6) with monitoring hemodynamic and electrophysiological variables, in which AF was induced by 10 s of burst pacing on atrial septum. Oseltamivir decreased AF incidence and AF duration, and prolonged AF cycle length in a dose-dependent manner. The low and high doses attained the peak plasma drug concentrations of 9.7 and 96.5 µg/mL, which were approximately 100 and 1000 times greater than those observed in human clinical cases, respectively. The low dose of oseltamivir decreased mean blood pressure without altering sinoatrial or idioventricular rate, whereas its high dose reduced each of them. Oseltamivir delayed inter-atrial conduction in dose- and frequency-dependent manners, whereas it prolonged atrial effective refractory period in dose-dependent but frequency-independent manners. The high dose prolonged ventricular effective refractory period, which was not detected with the low dose. These findings can be used for repurposing oseltamivir as an anti-AF drug candidate.


Assuntos
Antiarrítmicos , Antivirais/farmacologia , Antivirais/farmacocinética , Fibrilação Atrial/prevenção & controle , Fibrilação Atrial/fisiopatologia , Reposicionamento de Medicamentos , Fenômenos Eletrofisiológicos/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Oseltamivir/farmacologia , Oseltamivir/farmacocinética , Animais , Fibrilação Atrial/metabolismo , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Feminino , Infusões Intravenosas , Oseltamivir/administração & dosagem
10.
Heart Vessels ; 37(10): 1808-1815, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35426504

RESUMO

Elevation of the head and expiratory negative airway pressure (ENAP) ventilation can both significantly alter cardiovascular hemodynamics. The impact of head-up tilt (HUT) position on mechanically regulated ENAP ventilation-induced hemodynamics was assessed in microminipigs under halothane anesthesia (n = 4) in the absence and presence of adrenergic blockade. Supine ENAP ventilation increased cardiac output, but decreased mean right atrial, systolic pulmonary arterial, and mean left atrial pressures without significantly altering heart rate or aortic pressure. With HUT, the magnitude of ENAP ventilation-induced reduction in right and left atrial pressures was attenuated. HUT minimally altered ENAP ventilation-induced increase in cardiac output and reduction in pulmonary arterial systolic pressure. In addition, with up to 10 cm of HUT there was a significant increase in mean right atrial pressure with and without the ENAP ventilation, whereas HUT did not alter the other hemodynamic variables irrespective of ENAP ventilation. These observations suggest that head elevation augments venous return from the brain irrespective of the ENAP ventilation. Additional studies with pharmacological adrenergic blockade revealed that ENAP ventilation-induced increases in cardiac output and decreases in pulmonary systolic pressure were minimally altered by sympathetic nerve activity, irrespective of the head position. However, the observed ENAP ventilation-induced decreases in right and left atrial pressures were largely dependent upon adrenergic activity. These experimental findings may provide insight into future clinical application of HUT and ENAP for patients with head injury and hypotension.


Assuntos
Halotano , Hipertensão Pulmonar , Adrenérgicos , Pressão Sanguínea/fisiologia , Halotano/farmacologia , Frequência Cardíaca/fisiologia , Hemodinâmica/fisiologia , Humanos
11.
Gan To Kagaku Ryoho ; 49(2): 202-204, 2022 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-35249061

RESUMO

We report a successful case of robot-assisted surgery for Stage Ⅳ gastric cancer with liver metastasis. A 70s man diagnosed with advanced gastric cancer with S3 solitary liver metastasis, and received a chemotherapy with S-1 and cisplatin. After 4 courses of chemotherapy, liver metastatic lesion was disappeared. Thus, robotic distal gastrectomy and partial liver resection were performed. Operating time was 391 minutes, and amount of intraoperative blood loss was 11 mL. The postoperative course was uneventful, and the patient was discharged 11 days after surgery. Histologic examination revealed no viable malignant cells in the resected liver, with a diagnosis of ypT2N1M0, ypStage ⅡA. The patient is alive with no recurrence 12 months after surgery, without adjuvant chemotherapy.


Assuntos
Neoplasias Hepáticas , Procedimentos Cirúrgicos Robóticos , Neoplasias Gástricas , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cisplatino/uso terapêutico , Gastrectomia , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/cirurgia , Masculino , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia
12.
Gan To Kagaku Ryoho ; 49(13): 1820-1822, 2022 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-36733010

RESUMO

A 46-year-old man was referred to further treatment for a 20 mm submucosal tumor at the gastric angle found during a medical check-up. Endoscopic ultrasonography and chest abdominal contrast-enhanced CT revealed the tumor was located at the 4th(proper muscular)layer of the posterior wall of the gastric antrum and slightly enhanced. No metastasis was found. Although a biopsy failed to reveal an accurate diagnosis, GIST was clinically suspected. A robotic distal gastrectomy was planned to manage the residual gastric stricture. The intraoperative findings indicated possible passage of the remnant stomach; therefore, local resection was performed. The patient's postoperative course was uneventful, and he was discharged on postoperative day 9. A histopathological examination confirmed the diagnosis of a PAS-positive, S100-positive granular cell tumor with no nuclear atypia. These findings suggest that use of the robotic approach could help determine the stomach resection extent.


Assuntos
Coto Gástrico , Tumor de Células Granulares , Robótica , Neoplasias Gástricas , Humanos , Masculino , Pessoa de Meia-Idade , Gastrectomia , Tumor de Células Granulares/diagnóstico por imagem , Tumor de Células Granulares/cirurgia , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/patologia , Procedimentos Cirúrgicos Robóticos
13.
Gan To Kagaku Ryoho ; 49(13): 1862-1864, 2022 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-36733024

RESUMO

A 79-year-old male presented with epigastric discomfort and appetite loss. A type 1 advanced gastric tumor was detected by upper gastrointestinal endoscopy. Contrast-enhanced CT revealed a 7 cm mass with contrast effect at the greater curvature of the lower body of the stomach. No distant metastases were found. Staging laparoscopy confirmed gastric cancer with single giant lymph node metastasis, which was resectable, although the metastatic node possibly invaded the transverse colon. We performed total gastrectomy and partial colectomy. Pathological examination revealed the tumor was pT3N1; the mass was #4sa lymph node metastasis of gastric cancer. The postoperative course was uneventful. No tumor recurrence has been found for 12 months postoperatively.


Assuntos
Laparoscopia , Neoplasias Gástricas , Masculino , Humanos , Idoso , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/patologia , Metástase Linfática , Recidiva Local de Neoplasia/cirurgia , Excisão de Linfonodo , Gastrectomia , Linfonodos/patologia
14.
Gan To Kagaku Ryoho ; 49(13): 1867-1869, 2022 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-36733026

RESUMO

A 78-year-old male who had received laparoscopic total gastrectomy for upper gastric cancer 30 months ago(pT3N0, pStage ⅡB)was referred for further treatment for a 30-mm in size mass at the splenic hilum. The mass was suspected of lymph node metastasis was suspected. Two courses of SOX therapy failed to achieve the tumor response. Since there was no other metastasis, surgical treatment was indicated. Robot distal pancreatectomy with splenectomy was performed. There was no finding of peritoneal metastasis during the operation. The operative time was 384 min, the blood loss 22 mL, respectively. The postoperative course was uneventful, and he was discharged on the 12th postoperative day. The histopathological examination found that the resected mass was pancreatic metastasis of gastric cancer. Despite 3 courses of SOX therapy after the operation, the tumor recurred at the liver and paraaortic lymph nodes 2 months later. The second-line ramucirumab plus paclitaxel was started and has continued for 11 months with partial response. Although oncological benefit of surgical resection for isolated metastasis of gastric cancer, including pancreatic metastasis, was unclear, the robotic approach for such an atypical case was safe and feasible, leading to smooth initiation of postoperative systemic therapy.


Assuntos
Neoplasias Pancreáticas , Procedimentos Cirúrgicos Robóticos , Robótica , Neoplasias Gástricas , Masculino , Humanos , Idoso , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/patologia , Pancreatectomia , Excisão de Linfonodo , Recidiva Local de Neoplasia/cirurgia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/cirurgia , Gastrectomia
15.
Circ J ; 85(10): 1885-1891, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-33762525

RESUMO

BACKGROUND: Effects of rapid electrical defibrillation and ß-blockade on coronary ischemia/reperfusion-induced ventricular fibrillation (VF) during cardiopulmonary resuscitation (CPR) remain unknown.Methods and Results:After induction of VF by 30 min of ischemia followed by reperfusion, animals were treated with defibrillation alone (Group A, n=13), 2 min of open-chest cardiac massage followed by defibrillation (Group B, n=11), or the same therapy to Group B with propranolol (1 mg/kg, i.v.) treatment before ischemia/reperfusion (Group C, n=11). If return of spontaneous circulation (ROSC) was not attained, each therapy was repeated ≤3 times (Set-1). When ROSC was not obtained within Set-1, cardiac massage was applied to all animals followed by defibrillation, which was repeated ≤3 times (Set-2). ROSC after Set-1 was 8% in Group A, 82% in Group B and 82% in Group C, whereas that after Set-2 was 62% in Group A, 100% in Group B and 82% in Group C. Each animal with ROSC in Groups A (n=8) and B (n=11) showed sinus rhythm, whereas those in Group C (n=9) had sinus rhythm (n=5), atrial fibrillation (n=1), accelerated idioventricular rhythm (n=2) and atrioventricular block (n=1). Post ROSC heart rate and mean arterial pressure were significantly lower in Group C. CONCLUSIONS: Cardiac massage increased the likelihood of ROSC vs. rapid defibrillation, but ß-blocker pretreatment may worsen hemodynamics and electrical stability after ROSC.


Assuntos
Reanimação Cardiopulmonar , Parada Cardíaca , Animais , Modelos Animais de Doenças , Cães , Cardioversão Elétrica , Parada Cardíaca/terapia , Massagem Cardíaca , Humanos , Isquemia , Reperfusão , Fibrilação Ventricular/terapia
16.
J Pharmacol Sci ; 145(1): 16-22, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33357775

RESUMO

We compared dl-sotalol-induced electrocardiographic responses in intact dogs using a repeated-measures design among 1% halothane anesthesia, 1.5% isoflurane anesthesia with nitrous oxide (N2O), and conscious state to clarify influences of the anesthetics (n = 4). Basal PR interval was longer in halothane than either in isoflurane with N2O or in conscious state, reflecting sympathetic nerve suppression for the atrioventricular node by halothane. Both anesthetics exhibited longer basal QRS width than conscious state, suggesting their ventricular INa inhibition. Also, both anesthetics showed longer basal QT interval, QTcF and Tpeak-Tend than conscious state, indicating their ventricular IKr inhibition. Meanwhile, dl-sotalol prolonged PR interval similarly in isoflurane with N2O and in conscious state, which was less great in halothane, suggesting further sympathetic nerve suppression for the atrioventricular node might be limited in halothane. dl-Sotalol prolonged QT interval and QTcF >3 times greater in either of the anesthetics than in conscious state; moreover, dl-sotalol prolonged Tpeak-Tend similarly in both anesthetics, but hardly altered it in conscious state; indicating isoflurane with N2O as well as halothane may have reduced the repolarization reserve to increase the sensitivity of ventricle toward IKr suppression. Thus, isoflurane with nitrous oxide could be useful for in vivo IKr assay like halothane.


Assuntos
Anestesia/métodos , Estado de Consciência/efeitos dos fármacos , Eletrocardiografia/efeitos dos fármacos , Halotano , Isoflurano , Óxido Nitroso , Sotalol/farmacologia , Animais , Estado de Consciência/fisiologia , Cães , Halotano/farmacologia , Isoflurano/farmacologia , Masculino , Óxido Nitroso/farmacologia
17.
J Pharmacol Sci ; 145(3): 268-272, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33602507

RESUMO

We assessed concentration-dependent effects of halothane or isoflurane inhalation on the electrocardiographic and hemodynamic variables using a cross-over design in intact beagle dogs (n = 4). Elevation of inhaled halothane from 1.0% to 2.0% or isoflurane from 1.5% to 2.5% decreased the mean blood pressure and prolonged the QRS width without significantly altering the heart rate, PR interval or QT interval. However, the observed changes disappeared after regressions of both anesthetic conditions to their initial settings. These results indicate that hypotension-induced, reflex-mediated increase of sympathetic tone may have counterbalanced the direct negative chronotropic, dromotropic and repolarization slowing effects of the anesthetics.


Assuntos
Anestésicos/farmacologia , Eletrocardiografia/efeitos dos fármacos , Halotano/administração & dosagem , Halotano/farmacologia , Hemodinâmica/efeitos dos fármacos , Isoflurano/administração & dosagem , Isoflurano/farmacologia , Administração por Inalação , Animais , Pressão Sanguínea/efeitos dos fármacos , Estudos Cross-Over , Cães , Relação Dose-Resposta a Droga , Frequência Cardíaca/efeitos dos fármacos , Masculino , Sistema Nervoso Simpático/efeitos dos fármacos
18.
Heart Vessels ; 36(3): 424-429, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33136260

RESUMO

Lamotrigine has been used for patients with epilepsy and/or bipolar disorder, overdose of which induced the hypotension, elevation of the atrial pacing threshold, cardiac conduction delay, wide complex tachycardia, cardiac arrest and Brugada-like electrocardiographic pattern. To clarify how lamotrigine induces those cardiovascular adverse events, we simultaneously assessed its cardiohemodynamic and electrophysiological effects using the halothane-anesthetized dogs (n = 4). Lamotrigine was intravenously administered in doses of 0.1, 1 and 10 mg/kg/10 min under the monitoring of cardiovascular variables, possibly providing subtherapeutic to supratherapeutic plasma concentrations. The low or middle dose of lamotrigine did not alter any of the variables. The high dose significantly delayed the intra-atrial and intra-ventricular conductions in addition to the prolongation of ventricular effective refractory period, whereas no significant change was detected in the other variables. Lamotrigine by itself has relatively wide safety margin for cardiohemodynamics, indicating that clinically reported hypotension may not be induced through its direct action on the resistance arterioles or capacitance venules. The electrophysiological effects suggested that lamotrigine can inhibit Na+ channel in the in situ hearts. This finding may partly explain the onset mechanism of lamotrigine-associated cardiac adverse events in the clinical cases. In addition, elevation of J wave was induced in half of the animals, suggesting that lamotrigine may have some potential to unmask Brugada electrocardiographic genotype in susceptible patients.


Assuntos
Anestesia Geral/métodos , Doenças Cardiovasculares/induzido quimicamente , Eletrocardiografia , Halotano/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Função Ventricular Esquerda/efeitos dos fármacos , Anestésicos Inalatórios/farmacologia , Animais , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/fisiopatologia , Modelos Animais de Doenças , Cães , Sistema de Condução Cardíaco/fisiopatologia , Lamotrigina/toxicidade
19.
Heart Vessels ; 36(7): 1088-1097, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33763729

RESUMO

To characterize in vivo anti-atrial fibrillatory potential and pharmacological safety profile of ranolazine having INa,L plus IKr inhibitory actions in comparison with those of clinically available anti-atrial fibrillatory drugs; namely, dronedarone, amiodarone, bepridil and dl-sotalol in our previous studies, ranolazine dihydrochloride in sub-therapeutic (0.3 mg/kg) and supra-therapeutic (3 mg/kg) doses was intravenously infused over 10 min to the halothane-anesthetized dogs (n = 5). The low dose increased the heart rate, cardiac output and atrioventricular conduction velocity possibly via vasodilator action-induced, reflex-mediated increase of adrenergic tone. Meanwhile, the high dose decreased the heart rate, ventricular contraction, cardiac output and mean blood pressure, indicating that drug-induced direct actions may exceed the reflex-mediated compensation. In addition, it prolonged the atrial and ventricular effective refractory periods, of which potency and selectivity for the former were less great compared with those of the clinically-available drugs. Moreover, it did not alter the ventricular early repolarization period in vivo, but prolonged the late repolarization with minimal risk for re-entrant arrhythmias. These in vivo findings of ranolazine suggest that INa,L suppression may attenuate IKr inhibition-associated prolongation of early repolarization in the presence of reflex-mediated increase of adrenergic tone. Thus, ranolazine alone may be less promising as an anti-atrial fibrillatory drug, but its potential risk for inducing torsade de pointes will be small. These information can be used as a guide to predict the utility and adverse effects of anti-atrial fibrillatory drugs having multi-channel modulatory action.


Assuntos
Anestesia por Inalação/métodos , Fibrilação Atrial/tratamento farmacológico , Halotano/farmacologia , Átrios do Coração/fisiopatologia , Sistema de Condução Cardíaco/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Ranolazina/administração & dosagem , Potenciais de Ação/efeitos dos fármacos , Anestésicos Inalatórios/farmacologia , Animais , Fibrilação Atrial/fisiopatologia , Débito Cardíaco/efeitos dos fármacos , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Eletrocardiografia/efeitos dos fármacos , Feminino , Átrios do Coração/efeitos dos fármacos , Sistema de Condução Cardíaco/fisiopatologia , Infusões Intravenosas , Bloqueadores dos Canais de Sódio/administração & dosagem
20.
Gan To Kagaku Ryoho ; 48(13): 1862-1864, 2021 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-35045429

RESUMO

A 50-year-old woman diagnosed with clinical Stage Ⅲ esophageal squamous cell carcinoma, received 2 cycles of docetaxel, cisplatin, 5-fluorouracil(DCF)therapy followed by robotic esophagectomy. In the 15th postoperative day, she suddenly had difficulty in breathing and a chest CT finding showed a large amount of right pleural effusion. Thoracocentesis yield a 1 L of chylous fluid confirmed diagnosis with postoperative chylothorax and conservative treatment was initiated. However, chylothorax was not improved. Therefore, a lipiodol lymphangiography from the inguinal lymph node was performed at the 20th postoperative day. Although the site of leakage could not identify, amount of drained pleural effusion was gradually decreased after lymphangiography, and drain was decannulated in the 28th postoperative day. Lipiodol lymphangiography may be a useful modality for both diagnosis and treatment for chylothorax after esophagectomy.


Assuntos
Quilotórax , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Procedimentos Cirúrgicos Robóticos , Quilotórax/diagnóstico por imagem , Quilotórax/etiologia , Quilotórax/terapia , Neoplasias Esofágicas/cirurgia , Esofagectomia/efeitos adversos , Feminino , Humanos , Linfografia , Pessoa de Meia-Idade
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