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1.
Int J Urol ; 30(7): 586-591, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36946367

RESUMO

OBJECTIVES: We aimed to report the background of patients with vesicovaginal fistulas (VVFs) at our center, which has treated a relatively large number of such patients in Japan, as well as the ingenuity and outcomes of vesicovaginal fistula closure (VVFC). We also investigated the causes of VVFs. METHODS: A retrospective review was performed for 28 patients with VVFs treated at our center. Age, body mass index, etiology, site of fistula, and postoperative outcomes were investigated. RESULTS: Twenty-one (75%) fistulas occurred following hysterectomy. The overall success rate of VVFC was 85.7%, and the success rate limited to the first attempt was 89.5%. In 68% of cases, no bladder injury suspected as the cause of VVF was noticed during the surgery. Energy devices were used in all 12 patients for whom information on the type of device used for hysterectomy was confirmed. CONCLUSIONS: To our knowledge, this is the first report to evaluate a relatively large number of VVFCs in Japan. Although VVF is thought to be caused by bladder injury during hysterectomy, delayed thermal damage might also result in this pathology, even if there is no apparent intraoperative bladder injury.


Assuntos
Fístula Vesicovaginal , Feminino , Humanos , Fístula Vesicovaginal/epidemiologia , Fístula Vesicovaginal/etiologia , Fístula Vesicovaginal/cirurgia , Estudos Retrospectivos , Japão/epidemiologia , Bexiga Urinária/cirurgia , Procedimentos Cirúrgicos Urológicos/efeitos adversos
2.
J Obstet Gynaecol Res ; 48(5): 1255-1264, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35229411

RESUMO

AIMS: FemiCushion (FC) is a supportive device for pelvic organ prolapse (POP), but its effectiveness has not been evaluated with imaging studies. This study utilized magnetic resonance imaging (MRI) to evaluate the anatomic changes induced by FC use in patients with severe POP. METHODS: This prospective study examined patients with stage 3 or 4 POP who underwent treatment with FC and received a diagnostic MRI. Measurements were made in the midsagittal plane at rest and during straining with and without FC. The vertical distances from the lowest points of the anterior and posterior vaginal wall (A; P), uterine cervix or vaginal stump (C), and perineal body (PB) to the Pelvic Inclination Correction System line were measured, along with the lengths of the urogenital (UGH) and levator hiatus (LH). RESULTS: Twelve patients were included in the study. The median age was 72 (range, 56-84) years. All reference points were positioned significantly higher with the FC than without the FC (median ΔA: 11 mm, p = 0.005; ΔC: 14 mm, p = 0.011; ΔP: 6 mm, p = 0.008; ΔPB: 7 mm, p = 0.002). Median UGH and LH lengths during straining were significantly shorter with the FC than without the FC (UGH: 44 mm vs. 53 mm, p = 0.002; LH: 60 vs. 65 mm, p = 0.021). CONCLUSIONS: This is the first report on the use of MRI to measure the performance of FC. Our study demonstrates that FC effectively repositioned the organs involved in POP.


Assuntos
Prolapso de Órgão Pélvico , Idoso , Feminino , Humanos , Imageamento por Ressonância Magnética , Diafragma da Pelve/diagnóstico por imagem , Diafragma da Pelve/patologia , Prolapso de Órgão Pélvico/diagnóstico por imagem , Prolapso de Órgão Pélvico/patologia , Estudos Prospectivos , Vagina/diagnóstico por imagem
3.
Int Urogynecol J ; 32(11): 3089-3093, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33871668

RESUMO

We aimed to examine the usefulness of cystoscopic findings to guide mesh tension adjustment during laparoscopic sacrocolpopexy (LSC) to promote better repair of pelvic organ prolapse (POP) and prevent de novo stress urinary incontinence (SUI). In this technique, the bladder wall was observed using a cystoscope when various traction pressures were applied by pulling the mesh arm with forceps before fixation to the promontory during LSC. Adjustment was performed on 20 patients, and postoperative outcomes of POP repair and development of de novo SUI were evaluated. When excessive traction was applied on the mesh arm, a bladder neck opening and a cord-like elevation in the center of the trigone and posterior wall were observed in all cases. The tension was gradually loosened, and precisely when the above-mentioned cystoscopic finding ("Central Road") disappeared, an anatomically appropriate elevation of the vaginal apex was achieved; the mesh arm was fixed to the promontory. At 6 months after LSC, anterior wall recurrences were diagnosed in four patients (beyond the hymen in one) with few symptoms, while no occurrence of de novo SUI. Cystoscopic findings during mesh tension adjustment in LSC could be useful in achieving improved POP repair.


Assuntos
Laparoscopia , Prolapso de Órgão Pélvico , Incontinência Urinária por Estresse , Cistoscopia , Feminino , Humanos , Prolapso de Órgão Pélvico/cirurgia , Telas Cirúrgicas/efeitos adversos , Resultado do Tratamento , Incontinência Urinária por Estresse/etiologia , Incontinência Urinária por Estresse/cirurgia
4.
J Obstet Gynaecol Res ; 46(11): 2446-2449, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32820567

RESUMO

An enterocele is a peritoneal herniation through or into the vagina, typically as a posterior enterocele, which develops in the rectovaginal space (pouch of Douglas or cul-de-sac). An anterior enterocele in the vesicovaginal space is a rare condition, but a possible complication after cystectomy or hysterectomy. Herein, we report a rare case of anterior enterocele after cystectomy, which required semi-urgent intervention. The patient was a 78-year-old woman (gravida 2, para 2) who underwent laparoscopic radical cystectomy for bladder carcinoma 3 months earlier. Vaginal examination showed a large stage-3 anterior enterocele without the covering vaginal wall. A transvaginal surgery was performed to repair the vagina. Mesh and Martius flaps were needed to repair the vaginal defect. In conclusion, an anterior enterocele must be suspected when pelvic organ prolapse occurs after cystectomy, and surgical repair should be performed as soon as possible because an enterocele that lacks vaginal wall covering is at high risk of rupture.


Assuntos
Prolapso de Órgão Pélvico , Neoplasias da Bexiga Urinária , Idoso , Cistectomia/efeitos adversos , Feminino , Hérnia/etiologia , Humanos , Prolapso de Órgão Pélvico/cirurgia , Telas Cirúrgicas , Vagina/cirurgia
5.
J Med Ultrason (2001) ; 51(1): 95-101, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37740863

RESUMO

PURPOSE: The risk of pelvic floor muscle injury is commonly considered to be higher in vaginal than in cesarean delivery. This study aimed to compare levator ani muscle (LAM) elasticity after vaginal and cesarean delivery using shear wave elastography (SWE). METHODS: Postpartum women who underwent a single SWE evaluation 1 month after their first delivery were divided into vaginal and cesarean delivery groups. The elastic moduli of both sides of the LAM were measured in a horizontal section and compared between the groups. In addition, a subgroup analysis was performed to compare LAM elasticity according to the delivery method within the vaginal delivery group-normal vaginal delivery, episiotomy, and operative vaginal delivery. RESULTS: Sixty-two women were included (vaginal delivery, n = 47; elective cesarean section, n = 15). Multiple regression analysis revealed that the LAM elastic modulus was significantly lower in the vaginal delivery group than in the cesarean delivery group (right LAM: 44.2 vs. 72.7 kPa, p = 0.0036; left LAM 40.4 vs. 82.7 kPa, p < 0.0001). In the subgroup analysis, the right LAM elastic modulus was significantly lower in the operative vaginal delivery subgroup than in the normal vaginal delivery subgroup (p = 0.0131). However, there was no significant difference in the left LAM elastic modulus between the three subgroups. CONCLUSION: LAM elasticity was significantly lower after vaginal delivery than after cesarean delivery. Furthermore, the elasticity of the right LAM was lower after operative vaginal delivery than after normal vaginal delivery. SWE has the potential to provide an objective quantitative assessment of postpartum pelvic floor muscle recovery.


Assuntos
Cesárea , Técnicas de Imagem por Elasticidade , Feminino , Gravidez , Humanos , Cesárea/efeitos adversos , Parto Obstétrico/efeitos adversos , Elasticidade , Diafragma da Pelve/diagnóstico por imagem , Ultrassonografia
6.
J Dermatol ; 51(2): 234-242, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38149403

RESUMO

Acute zoster-associated pain develops in most patients with herpes zoster. Nonopioid analgesics are usually used to treat acute zoster-associated pain but are frequently ineffective. We administered intravenous fosphenytoin, the prodrug of phenytoin, to patients with acute zoster-associated pain to examine its analgesic efficacy and safety. At 13 medical institutions in Japan, we conducted a phase II, double-blind, placebo-controlled, randomized trial of intravenous fosphenytoin in Japanese inpatients with acute zoster-associated pain for whom nonopioid analgesics had shown an insufficient analgesic effect. The patients were randomly assigned (1:1:1) to receive a single intravenous dose of fosphenytoin at 18 mg/kg (high dose), a single intravenous dose of fosphenytoin at 12 mg/kg (low dose), or placebo. The primary endpoint was the mean change per hour (slope) in the numerical rating scale score from the baseline score until 120 min after dosing. Seventeen patients were randomly assigned to the low-dose fosphenytoin group (n = 6, median age 62.5 years, range 39-75 years), high-dose fosphenytoin group (n = 5, median age 69.0 years, range 22-75 years), and placebo group (n = 5, median age 52.0 years, range 38-72 years). One patient was excluded because of investigational drug dilution failure. This study was discontinued because of the influences of coronavirus disease 2019. The slope was significantly lower in the high- and low-dose fosphenytoin groups than in the placebo group (P < 0.001 and P = 0.016, respectively). Responsiveness to intravenous fosphenytoin (≥2-point reduction in the numerical rating scale score from baseline to 120 min after dosing) was inferred at plasma total phenytoin concentrations of 10-15 µg/mL. Treatment-emergent adverse events caused no safety concerns in the clinical setting and intravenous fosphenytoin was well tolerated. Intravenous fosphenytoin appears to be an effective and promising alternative treatment for acute zoster-associated pain. Trial Registration: ClinicalTrials.gov NCT04139330.


Assuntos
Herpes Zoster , Dor , Fenitoína , Adulto , Idoso , Humanos , Pessoa de Meia-Idade , Adulto Jovem , Analgésicos , Analgésicos não Narcóticos/farmacologia , Método Duplo-Cego , Herpes Zoster/complicações , Herpes Zoster/tratamento farmacológico , Herpesvirus Humano 3 , Dor/tratamento farmacológico , Dor/etiologia , Fenitoína/efeitos adversos
7.
Masui ; 62(12): 1426-9, 2013 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-24498775

RESUMO

A 68-year-old man was admitted to our hospital with an open fracture. Physical examinations of the patient showed normal status, and laboratory examination and chest X-ray film showed no abnormal findings. Electrocardiogram revealed ST-segment elevations in V2 and V3, but diagnosed as an early repolarization by a cardiologist. We noticed when he entered the OR that highly sensitive troponin I (hsTnI) level was 0.303 ng ml-1 (cut off : 0.04ng ml-1). Since he had no symptoms suggesting acute coronary syndrome, we proceeded with the operation partly supported by the golden time for the operation. Except Spo2 92% on arrival at the OR, the anesthetic course was uneventful. Soon after extubation, Spo2 dropped below 90% and he was re-intubated. After a thorough evaluation, he was diagnosed with acute myocardial infarction (AMI) and underwent emergency percutaneous coronary intervention. In this case, hsTnI value was slightly elevated before the surgery. Since there is increasing evidence that hsTnI is a sensitive and specific marker for early diagnosis of AMI, we have to take the value into consideration.


Assuntos
Infarto do Miocárdio/diagnóstico , Período Pré-Operatório , Troponina I/sangue , Acidentes de Trabalho , Idoso , Biomarcadores/sangue , Erros de Diagnóstico , Tratamento de Emergência , Traumatismos dos Dedos/cirurgia , Fraturas Expostas/cirurgia , Insuficiência Cardíaca/etiologia , Humanos , Masculino , Infarto do Miocárdio/complicações , Infarto do Miocárdio/cirurgia , Intervenção Coronária Percutânea , Complicações Pós-Operatórias/etiologia , Sensibilidade e Especificidade , Stents , Fatores de Tempo
8.
Bioorg Med Chem ; 20(16): 4968-77, 2012 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-22831798

RESUMO

A methanol extract of the flowers of Mammea siamensis (Calophyllaceae) was found to inhibit nitric oxide (NO) production in lipopolysaccharide-activated RAW264.7 cells. From the extract, two new geranylated coumarins, mammeasins A (1) and B (2), were isolated together with 17 known compounds including 15 coumarins. The structures of 1 and 2 were determined on the basis of their spectroscopic properties as well as of their chemical evidence. Among the isolates, 1 (IC(50) = 1.8 µM), 2 (6.4 µM), surangins B (3, 5.0 µM), C (4, 6.8 µM), and D (5, 6.2 µM), kayeassamins E (7, 6.1 µM), F (8, 6.0 µM), and G (9, 0.8 µM), mammea A/AD (11, 1.3 µM), and mammea E/BB (16, 7.9 µM) showed NO production inhibitory activity. Compounds 1, 9, and 11 were found to inhibit induction of inducible nitric oxide synthase (iNOS). With regard to mechanism of action of these active constituents (1, 9, and 11), suppression of STAT1 activation is suggested to be mainly involved in their suppression of iNOS induction.


Assuntos
Cumarínicos/farmacologia , Inibidores Enzimáticos/farmacologia , Mammea/química , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Animais , Células Cultivadas , Cumarínicos/química , Cumarínicos/isolamento & purificação , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Flores/química , Camundongos , Estrutura Molecular , Óxido Nítrico Sintase Tipo II/biossíntese , Óxido Nítrico Sintase Tipo II/metabolismo , Estereoisomerismo , Relação Estrutura-Atividade
13.
Medicine (Baltimore) ; 96(21): e6968, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28538395

RESUMO

RATIONALE: Palisaded neutrophilic and granulomatous dermatitis (PNGD) is a benign, inflammatory dermatosis with distinct histopathological features often observed in patients with systemic diseases. There were no reports of PNGD without underlying systemic diseases as an underlying cause of hypercalcemia. Herein, we report a case of a 62-year-old man with hypercalcemia due to PNGD, but with no underlying systemic diseases, including tuberculosis, sarcoidosis, or vasculitis. PATIENT CONCERNS: Laboratory tests showed an elevated C-reactive protein level, an elevated corrected calcium level, a normal 25-hydroxyvitamin D level, and an elevated 1,25-dihydroxyvitamin D level. There were no other abnormalities to explain the hypercalcemia. Positron emission tomography-computed tomography showed abnormal uptake in his skin. Histopathological examination of the skin showed palisaded granulomatous infiltrate in the dermis. Neutrophils, degenerated collagen, and fibrin were present in the centers of the palisades without prominent mucin. There were no eosinophils, central necrosis, or necrotizing vasculitides. These features were consistent with PNGD. DIAGNOSES: A diagnosis of PNGD with hypercalcemia was established. INTERVENTIONS: Oral prednisolone was administered to the patient. OUTCOMES: After treatment, his symptoms resolved, and his calcium, 1,25-dihydroxyvitamin D and CRP levels returned to normal. Skin specimens before and after treatment were assessed using immunohistochemistry for 1a-hydroxylase. Granuloma and epidermal cells were 1a-hydroxylase-positive before treatment. After treatment, the granuloma diminished in size and the 1ahydroxylase-positive areas of the epidermal cells decreased. LESSONS: This case was particularly unique because increased 1a-hydroxylase expression in the granuloma and epidermal cells seemed to result in hypercalcemia due to excessive transformation of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D. Physicians should consider PNGD as an underlying cause of hypercalcemia.


Assuntos
Dermatite/complicações , Dermatite/diagnóstico , Hipercalcemia/diagnóstico , Hipercalcemia/etiologia , Dermatite/tratamento farmacológico , Dermatite/patologia , Diagnóstico Diferencial , Humanos , Hipercalcemia/tratamento farmacológico , Hipercalcemia/patologia , Masculino , Pessoa de Meia-Idade
14.
Oncogene ; 22(9): 1340-8, 2003 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-12618759

RESUMO

Homologues of the Escherichia coli (E. coli) Ras-like protein (ERA), a GTP-binding protein with RNA binding activity, have recently been found in various species, including human, mouse, and Antirrhinum majus. Depletion of prokaryotic ERA blocks cell division without affecting chromosome segregation. However, the physiological function of eukaryotic ERA is largely unknown. We have performed a genetic analysis of chicken ERA (GdERA) in DT40 cells. Depletion of GdERA diminished the growth rate of the cells, accompanied by an accumulation of apoptotic cells. The analysis of cell cycle indicates that the elimination of GdERA caused arrest at G1 phase, but not at M phase, which highlights the distinct role of vertebrate ERA in the cell cycle progression compared to prokaryotic ERA. Furthermore, human ERA (HsERA) rescued the phenotype of GdERA-deficient cells, whereas a mutant of HsERA deprived of RNA-binding activity did not. These data suggest that vertebrate ERA regulates the G1 phase progression via an as yet unknown molecular mechanism, which involves RNA recognition by ERA.


Assuntos
Apoptose/fisiologia , Fase G1/fisiologia , Proteínas de Ligação ao GTP/fisiologia , Proteínas de Ligação a RNA/fisiologia , Animais , Divisão Celular , Linhagem Celular/citologia , Galinhas/metabolismo , Sequência Consenso , Doxiciclina/farmacologia , Proteínas de Ligação ao GTP/deficiência , Proteínas de Ligação ao GTP/genética , Marcação de Genes , Genes Reporter , Luciferases/biossíntese , Luciferases/genética , Células Procarióticas/metabolismo , Regiões Promotoras Genéticas/efeitos dos fármacos , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas de Ligação a RNA/genética , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Transfecção , Vertebrados/metabolismo , Proteína bcl-X
17.
J Hypertens ; 20(3): 447-54, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11875312

RESUMO

OBJECTIVE: Localized release of Ca2+ from the sarcoplasmic reticulum (SR) toward the plasmalemma, sometimes visualized as Ca2+ sparks, can activate Ca2+-activated K+ (KCa) channels. We have already reported that the addition of charybdotoxin (ChTX), a blocker of KCa channels, to the resting state of arteries from spontaneously hypertensive rats (SHR) caused a powerful contraction, suggesting that KCa channels were active in the resting state. This study aimed to determine whether the Ca2+ responsible for activity of KCa channels was derived from SR. METHODS: Possible mechanisms underlying the ChTX-induced contractions were examined in endothelium-denuded strips of femoral, mesenteric, small mesenteric and carotid arteries from 13-week-old SHR and normotensive Wistar-Kyoto (WKY) rats by using selective inhibitors of the Ca2+ spark process. RESULTS: ChTX (100 nmol/l) induced a contraction in the SHR arteries. The ChTX-induced contractions were increased by a moderate membrane depolarization by 15.9 mmol/l K+ and were abolished by nifedipine (100 nmol/l). When SR Ca2+ was depleted by treatment of the strips with ryanodine (10 mumol/l) plus caffeine (20 mmol/l) or with thapsigargin (100 nmol/l), the ChTX-induced contraction was decreased in femoral, mesenteric and small mesenteric arteries and was almost abolished in the carotid artery. A similar phenomenon can be observed in arteries from WKY rats after a moderate membrane depolarization. In both SHR and WKY rats, SR Ca2+-dependent ChTX-induced contraction always represents 20-30% of the maximal K+-induced contraction. CONCLUSIONS: We conclude that activation of KCa channels depended upon influx of Ca2+ through L-type Ca2+ channels and release of Ca2+ from the SR, suggesting that recycling of entering Ca2+ from the superficial SR toward the plasmalemma sufficiently elevated Ca2+ near these channels to activate them.


Assuntos
Artérias/fisiopatologia , Cálcio/fisiologia , Hipertensão/fisiopatologia , Canais de Potássio Cálcio-Ativados/metabolismo , Ratos Endogâmicos SHR/fisiologia , Retículo Sarcoplasmático/metabolismo , Animais , Artérias/efeitos dos fármacos , Artérias Carótidas/efeitos dos fármacos , Artérias Carótidas/fisiopatologia , Charibdotoxina/farmacologia , Técnicas In Vitro , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/fisiopatologia , Peptídeos/farmacologia , Ratos , Ratos Endogâmicos WKY , Valores de Referência , Descanso , Rianodina/farmacologia , Tapsigargina/farmacologia , Vasoconstrição/efeitos dos fármacos
18.
Hypertens Res ; 25(2): 221-30, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12047038

RESUMO

To clarify whether the Ca2+ uptake function of the sarcoplasmic reticulum (SR) during arterial contraction is altered in hypertension, the effects of cyclopiazonic acid (CPA) and thapsigargin, which inhibit SR Ca2+-ATPase, on the contractile responses to Bay k 8644, an agonist of L-type Ca2+ channels, were compared in endothelium-denuded strips of carotid arteries from 13-week-old spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). The addition of Bay k 8644 (1-300 nM) to the strips caused a concentration-dependent contraction that was larger in SHR than in WKY. The contractile responses to Bay k 8644 were augmented by CPA (10 microM) or thapsigargin (100 nM) in both strains. This augmentation was greater in SHR. Each of CPA and thapsigargin induced a relatively transient contraction, and both of these contractions were larger in SHR than in WKY. The basal 45Ca influx in this artery was larger in SHR than in WKY. The addition of caffeine (1-20 mM) caused a transient contraction that was larger in SHR than in WKY. Our results indicate that 1) the large Ca2+ influx during rest in the SHR carotid artery is strongly buffered by Ca2+ uptake into the superficial SR; and 2) the Ca2+ uptake function of the SR during the contraction with Bay k 8644 was increased in SHR compared with WKY. We conclude that the SHR carotid artery has an increased total capacity of SR for Ca2+ storage as an attempt to compensate for the large Ca2+ influx.


Assuntos
Cálcio/metabolismo , Artérias Carótidas/metabolismo , Hipertensão/metabolismo , Ratos Endogâmicos SHR/metabolismo , Retículo Sarcoplasmático/metabolismo , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Animais , Soluções Tampão , Cafeína/farmacologia , Agonistas dos Canais de Cálcio/farmacologia , Artérias Carótidas/efeitos dos fármacos , Artérias Carótidas/fisiopatologia , Inibidores Enzimáticos/farmacologia , Hipertensão/fisiopatologia , Técnicas In Vitro , Indóis/farmacologia , Masculino , Ratos , Ratos Endogâmicos WKY , Tapsigargina/farmacologia , Vasoconstrição
19.
Hypertens Res ; 25(2): 231-9, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12047039

RESUMO

We compared the Ca2+ buffering function of the superficial sarcoplasmic reticulum (SR) during rest and during contraction in endothelium-denuded strips of small mesenteric arteries from 13-week-old spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). The addition of caffeine (1-20 mM) caused a transient contraction in both strains, and the contraction was significantly larger in SHR. When the SR Ca2+ buffering function was eliminated by cyclopiazonic acid (CPA; 10 microM) or thapsigargin (100 nM), both of which inhibit SR Ca2+-ATPase, or by ryanodine (10 microM), which depletes the SR Ca2+, there was a larger contraction in SHR than in WKY, suggesting that the Ca2+ buffering function of the SR during rest is more important in SHR than in WKY. Judging from the augmenting effects of these three agents on the contractile responses to Bay k 8644 (1-300 nM), an agonist of L-type Ca2+ channels, or norepinephrine (10(-9)-10(-4) M), an alpha-adrenoceptor agonist, the effects were significantly greater in SHR than in WKY. We conclude that 1) the Ca2+ influx during rest and during stimulation with Bay k 8644 or norepinephrine is strongly buffered by Ca2+ uptake into the superficial SR in the small mesenteric arteries from SHR and WKY; and 2) these Ca2+ buffering functions are increased in SHR because of the larger capacity of SR for Ca2+ storage.


Assuntos
Cálcio/metabolismo , Hipertensão/metabolismo , Artérias Mesentéricas/metabolismo , Ratos Endogâmicos SHR/metabolismo , Retículo Sarcoplasmático/metabolismo , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Agonistas alfa-Adrenérgicos/farmacologia , Animais , Soluções Tampão , Agonistas dos Canais de Cálcio/farmacologia , Inibidores Enzimáticos/farmacologia , Hipertensão/fisiopatologia , Técnicas In Vitro , Indóis/farmacologia , Artérias Mesentéricas/efeitos dos fármacos , Norepinefrina/farmacologia , Ratos , Ratos Endogâmicos WKY , Rianodina/farmacologia , Tapsigargina/farmacologia , Vasoconstrição/efeitos dos fármacos
20.
Hypertens Res ; 26(1): 97-106, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12661918

RESUMO

Since Y-27632, a specific inhibitor of Rho kinase, decreases the blood pressure in spontaneously hypertensive rats (SHR), it is suggested that Rho kinase is involved in the pathophysiology of hypertension. However, the effects of Y-27632 on isolated resistance arteries have never been determined. This study aimed to examine the possible role of the Rho/Rho kinase pathway during arterial contraction in isolated resistance arteries from SHR. The profile of arterial relaxant effects of Y-27632 was compared in endothelium-denuded strips of small and large mesenteric arteries from 13-week-old SHR and normotensive Wistar-Kyoto rats (WKY). The addition of 10(-6) mol/l norepinephrine (NE) to the strips of small arteries caused an initial peak followed by a tonic contraction in both strains. There was no difference between the two strains in either the initial peak or the tonic contraction. The addition of Y-27632 (0.3-3 micromol/l) to the tonic contraction of these strips caused a concentration-dependent relaxation in both strains. The relaxation was greater in SHR than in WKY. Similar results were observed in strips of large arteries. The relaxant effects of Y-27632 were greater in the large artery than in the small artery. Y-27632 also induced a concentration-dependent relaxation in strips precontracted with 65.9 mmol/l K+ depolarization. In both arteries, this relaxation was greater in SHR. The relaxant effects of Y-27632 were greater in the K+-contracted strips than in the NE-contracted strips. We conclude that Y-27632 shows the greater relaxant effects on the SHR arteries, and the effects are more evident in the large artery and in the K+-contracted strips.


Assuntos
Amidas/farmacologia , Inibidores Enzimáticos/farmacologia , Hipertensão/metabolismo , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/enzimologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Piridinas/farmacologia , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo L/metabolismo , Hipertensão/tratamento farmacológico , Peptídeos e Proteínas de Sinalização Intracelular , Contração Isométrica/efeitos dos fármacos , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/enzimologia , Nifedipino/farmacologia , Norepinefrina/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Vasoconstritores/farmacologia , Vasodilatação/efeitos dos fármacos , Quinases Associadas a rho
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