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1.
ESC Heart Fail ; 2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38845360

ABSTRACT

AIMS: This study aimed to investigate the association between the time to achieve walkability after cardiac surgery and the risk of cardiovascular disease after hospital discharge. METHODS: We conducted a prospective cohort study involving 553 ambulatory patients aged 71.5 (range, 64.0-77.0) years who underwent cardiac surgery. All patients were divided into five groups based on the time to achieve walkability ≥100 m within 1, 2, 3, 4 or 5 days after cardiac surgery. We examined the risk of post-cardiovascular disease outcomes, including readmission due to heart failure, ischaemic heart disease and other cardiovascular disease, according to the time to achieve walkability with reference to 5 days using the Fine and Gray regression model, considering competing risks. RESULTS: In the survival curve analysis, we examined the time to experience post-cardiovascular disease incidence after hospital discharge. During a median of 3.3 years of follow-up, 118 patients developed cardiovascular disease. We observed a positive association between the time to achieve walkability and cardiovascular disease risk, particularly heart failure. The multivariate hazard ratios (95% confidence intervals) for heart failure readmission were N/A (not assessed due to the sample size being too small) for 1 day, 0.31 (0.10-0.99) for 2 days, 0.60 (0.21-1.79) for 3 days and 0.76 (0.22-2.72) for 4 days (P for trend = 0.032). CONCLUSIONS: The shorter walkability achievement time was associated with a lower risk of cardiovascular diseases, more specifically heart failure readmission, among patients who underwent cardiac surgery. The time required to achieve walkability is a useful predictor for cardiovascular diseases after hospital discharge.

2.
Article in English | MEDLINE | ID: mdl-38754123

ABSTRACT

A 46-year-old male patient was referred to our hospital due to the presence of a coronary aneurysm showing a tendency to enlarge. Subsequent coronary angiography revealed a diagnosis of coronary aneurysm with a concomitant coronary-pulmonary artery fistula. The patient underwent a successful surgical repair, and postoperatively, experienced an uneventful recovery with no residual shunt or aneurysm.

3.
Article in English | MEDLINE | ID: mdl-38574387

ABSTRACT

Thoracic endovascular repair for type IIIb aortic dissection results in the disappearance of false lumen perfusion in the abdominal aorta in only about 20% of cases, with concern for expansion in the long term. Staged endovascular therapy with intervention on all re-entries can lead to complete false lumen thrombosis and remodelling of the entire aorta. This approach could be an option in cases in which long-term expansion is anticipated.

4.
Kyobu Geka ; 77(3): 191-195, 2024 Mar.
Article in Japanese | MEDLINE | ID: mdl-38465491

ABSTRACT

We experienced a case of surgical aortic valve re-replacement due to structural valve deterioration caused by pannus formation 4 years after transcatheter aortic valve replacement( TAVR). The patient underwent surgery because the mean transvalvular pressure gradient increased to 48 mmHg on echocardiography. Contrast-enhanced computed tomography (CT) was useful for predicting the site of adhesion to surrounding tissue preoperatively and exploring the presence of the pannus. Intraoperative findings showed the TAVR valve was covered with neointima except around the origins of the left and right coronary arteries and was firmly adhered to the surrounding tissues. As residual pannus was present in the subvalvular tissues, it was carefully removed. The explanted TAVR valve functioned well with good opening and closure. The postoperative course was uneventful. Pannus formation can result from mechanical stress. TAVR valves put significantly greater stress on the left ventricular outflow tract than surgical valves and may be more likely to cause pannus formation.


Subject(s)
Aortic Valve Stenosis , Heart Valve Prosthesis Implantation , Heart Valve Prosthesis , Transcatheter Aortic Valve Replacement , Ventricular Outflow Obstruction, Left , Ventricular Outflow Obstruction , Humans , Transcatheter Aortic Valve Replacement/adverse effects , Pannus , Heart Valve Prosthesis Implantation/adverse effects , Aortic Valve/diagnostic imaging , Aortic Valve/surgery , Aortic Valve Stenosis/diagnostic imaging , Aortic Valve Stenosis/surgery , Heart Valve Prosthesis/adverse effects , Treatment Outcome , Ventricular Outflow Obstruction/diagnostic imaging , Ventricular Outflow Obstruction/etiology , Ventricular Outflow Obstruction/surgery
5.
Kyobu Geka ; 76(9): 669-672, 2023 Sep.
Article in Japanese | MEDLINE | ID: mdl-37735721

ABSTRACT

CASE: 82-year-old female. In October 2020, the patient underwent transcatheter aortic valve implantation( TAVI)[Evolut PRO R 23 mm] via left subclavian artery approach for severe aortic valve stenosis. The patient was discharged home without any issues. However, nine months after surgery, the patient was hospitalized at another hospital for a right upper arm fracture and developed a fever. The patient was transferred to our hospital and was diagnosed with Enterococcal bacteremia while receiving antibiotic treatment. Echocardiography revealed leaflet thickening and cord-like structure on the artificial valve, and a diagnosis of prosthetic valve endocarditis (PVE) was made. The patient then underwent surgical removal of the valve. The patient had a good postoperative course and completed 4 weeks of antibiotic treatment before being transferred back to the referring hospital 31 days after surgery. TAVI made unprecendented revolution in the treatment of aortic valve stenosis. TAVI is often used for elderly patients with comorbidities because of high perioperative risk is for surgical aortic valve replacement. Although TAVI is widely promoted for its benefits, it is not without limitations. In cases with more than one year of follow-up, there are many complications and the risk of surgery is high. There have been few reports of cases from Japan requiring surgical removal of TAVI valve. In this case, PVE was diagnosed nine months after TAVI and the patient had a good outcome.


Subject(s)
Aortic Valve Stenosis , Bioprosthesis , Endocarditis, Bacterial , Endocarditis , Heart Valve Prosthesis , Transcatheter Aortic Valve Replacement , Aged , Female , Humans , Aged, 80 and over , Transcatheter Aortic Valve Replacement/adverse effects , Heart Valve Prosthesis/adverse effects , Aortic Valve Stenosis/diagnostic imaging , Aortic Valve Stenosis/surgery
6.
Kyobu Geka ; 74(12): 1020-1023, 2021 Nov.
Article in Japanese | MEDLINE | ID: mdl-34795146

ABSTRACT

We report a rare case of isolated pulmonary valve endocarditis in a 60-year-old man without congenital heart defects. He had a persistent fever and back neck pain after pulling out his teeth. Echo cardiography revealed a mobile vegetation (measuring 53 mm in size) adhering to the pulmonary valve and blood cultures showed the presence of Staphylococcus aureus( S. aureus). Because of mobile vegetation, pulmonic embolism and presence of S. aureus, surgical treatment was selected. During surgical procedure, we found that the vegetation had destroyed markedly pulmonary valve leaflets. After excising pulmonary valve leaflets, we implanted a bioprosthetic valve and enlarged the pulmonary artery with autologous pericardium. A year after surgery, the patient is stable with no sign of infection.


Subject(s)
Endocarditis, Bacterial , Endocarditis , Heart Defects, Congenital , Pulmonary Valve , Endocarditis, Bacterial/complications , Endocarditis, Bacterial/diagnostic imaging , Endocarditis, Bacterial/surgery , Heart Defects, Congenital/complications , Heart Defects, Congenital/diagnostic imaging , Heart Defects, Congenital/surgery , Humans , Male , Middle Aged , Pulmonary Valve/diagnostic imaging , Pulmonary Valve/surgery , Staphylococcus aureus
7.
Kyobu Geka ; 74(11): 959-961, 2021 Oct.
Article in Japanese | MEDLINE | ID: mdl-34601482

ABSTRACT

Myxomas account for the vast majority of heart tumors in adults. About 70% originate in the left atrium, while about 10% of these are reported to originate in the right atrium. A 70-year-old man with dyspnea, was found to have a giant right atrial mass by echocardiography, and tumor resection was performed under cardiopulmonary bypass( CPB) through a median sternotomy. At weaning from CPB the patient was hemodynamically unstable. Intraoperative echocardiography showed severe tricuspid regurgitation( TR), and tricuspid annuloplasty was performed. The postoperative course was uneventful and histopathological examination confirmed that the tumor was a myxoma. It is important to keep in mind that regurgitation of the atrio-ventricular valve might occur after resection of atrial myxoma.


Subject(s)
Heart Neoplasms , Myxoma , Tricuspid Valve Insufficiency , Adult , Aged , Echocardiography , Heart Atria/diagnostic imaging , Heart Atria/surgery , Heart Neoplasms/diagnostic imaging , Heart Neoplasms/surgery , Humans , Male , Myxoma/diagnostic imaging , Myxoma/surgery , Tricuspid Valve Insufficiency/diagnostic imaging , Tricuspid Valve Insufficiency/surgery
8.
Kyobu Geka ; 73(9): 686-689, 2020 Sep.
Article in Japanese | MEDLINE | ID: mdl-32879273

ABSTRACT

We experienced a surgical case of Stanford type A acute aortic dissection with abdominal aortic aneurysm (AAA) associated with ectopic kidney. Computerized tomography did not detect any ulcer-like projections, but 3 days later, it appeared, and emergency surgery was performed. Second-stage surgery was selected and done later to repair AAA. The right kidney was an ectopic pelvic kidney. The renal arteries had branched off from the left common iliac artery, and the renal artery lumen narrowed. With a 4 Fr catheter, cold Ringer's solution was given to protect the kidneys during surgery. The patient showed no deterioration of kidney function and made good progress. After rehabilitation, the patient had no complications and was discharged from the hospital.


Subject(s)
Aortic Aneurysm, Abdominal/surgery , Aortic Dissection , Blood Vessel Prosthesis Implantation , Kidney Diseases , Aorta, Abdominal , Humans , Kidney , Renal Artery/surgery , Treatment Outcome
9.
Kyobu Geka ; 73(8): 563-571, 2020 Aug.
Article in Japanese | MEDLINE | ID: mdl-32879281

ABSTRACT

The fundamental treatment of Stanford type A acute aortic dissection is a lifesaving emergency surgery in our hospital. We perform hemiarch replacement with a focus on entry tear, but an extended surgery is also performed only when resection of the entry tear is difficult. The outcomes of current therapeutic policy, along with the short-term and the long-term outcomes of different sites of entry tear, were examined retrospectively. Three hundred and twenty surgery of Stanford type A acute aortic dissection were performed between 1991 and 2015 at our hospital. Their short-term and long-term outcomes were examined after dividing them into 7 groups according to their entry sites. We also investigated surgical methods and effects of presence/absence of residual entry tear. As a result, overall hospital mortality was 13.1%. There was no significant difference in either shortterm or long-term outcome among the groups. Likewise, no significant difference was observed in the surgical methods or the presence/absence of residual entry tear. Recently, minimally invasive procedures, such as stent-grafting, have been applied to manage the residual entry tear. Therefore, an aggressive extended surgery is no longer inevitable and our current therapeutic policy is considered reasonable.


Subject(s)
Aortic Aneurysm, Thoracic/surgery , Aortic Dissection/surgery , Blood Vessel Prosthesis Implantation , Acute Disease , Humans , Postoperative Complications/surgery , Retrospective Studies , Treatment Outcome
10.
Kyobu Geka ; 73(2): 146-148, 2020 Feb.
Article in Japanese | MEDLINE | ID: mdl-32393724

ABSTRACT

A 70-year-old man was admitted to our hospital because of shortness of breath. He had undergone coronary artery bypass grafting at another hospital 18 years before. We had detected his saphenous vein graft to the right coronary artery being aneurysmal 3 years before. The aneurysm had grown from 23 mm to 42 mm during the follow-up. Because of an angina-like symptom and the possibility of rupture, we performed resection of the aneurysm and redo coronary artery bypass grafting to the right coronary artery using another saphenous vein. His symptom has disappeared since then. Saphenous vein graft aneurysm needs close follow-up even when conservative therapy is selected.


Subject(s)
Aneurysm , Coronary Artery Bypass/adverse effects , Saphenous Vein , Aged , Aneurysm/etiology , Angina Pectoris , Coronary Vessels , Humans , Male
11.
Eur Heart J Acute Cardiovasc Care ; 9(4_suppl): S175-S183, 2020 Nov.
Article in English | MEDLINE | ID: mdl-31081678

ABSTRACT

BACKGROUND: Little is known about the association between serum potassium level on hospital arrival and neurological outcome after out-of-hospital cardiac arrest (OHCA). We investigated whether the serum potassium level on hospital arrival had prognostic indications for patients with OHCA. METHODS: This prospective, multicenter observational study conducted in Osaka, Japan (CRITICAL study) enrolled consecutive patients with OHCA transported to 14 participating institutions from 2012 to 2016. We included adult patients aged ⩾18 years with OHCA of cardiac origin who achieved return of spontaneous circulation and whose serum potassium level on hospital arrival was available. Based on the serum potassium level, patients were divided into four quartiles: Q1 (K ⩽3.8 mEq/L), Q2 (3.8< K⩽4.5 mEq/L), Q3 (4.5< K⩽5.6 mEq/L) and Q4 (K >5.6 mEq/L). The primary outcome was one-month survival with favorable neurological outcome, defined as cerebral performance category scale 1 or 2. RESULTS: A total of 9822 patients were registered, and 1516 of these were eligible for analyses. The highest proportion of favorable neurological outcome was 44.8% (189/422) in Q1 group, followed by 30.3% (103/340), 11.7% (44/375) and 4.5% (17/379) in the Q2, Q3 and Q4 groups, respectively (p<0.001). In the multivariable analysis, the proportion of favorable neurological outcome decreased as the serum potassium level increased (p<0.001). CONCLUSIONS: High serum potassium level was significantly and dose-dependently associated with poor neurological outcome. Serum potassium on hospital arrival would be one of the effective prognostic indications for OHCA achieving return of spontaneous circulation.


Subject(s)
Hospitalization/statistics & numerical data , Out-of-Hospital Cardiac Arrest/blood , Potassium/blood , Registries , Aged , Aged, 80 and over , Biomarkers/blood , Female , Humans , Japan/epidemiology , Male , Middle Aged , Out-of-Hospital Cardiac Arrest/mortality , Prognosis , Prospective Studies , Survival Rate/trends
12.
Geriatr Gerontol Int ; 19(11): 1088-1095, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31622019

ABSTRACT

AIM: The purpose of this study was to evaluate the out-of-hospital cardiac arrest (OHCA) characteristics of patients stratified by age who had resuscitation attempted and were transported to tertiary emergency medical institutions in Osaka Prefecture, Japan; especially those of advanced age. METHODS: A prospective, population-based, observational review was carried out of consecutive OHCA patients with emergency responder resuscitation attempts from July 2012 to December 2016 in Osaka, Japan. Patients were classified into four groups: (i) 18-64 years; (ii) 65-74 years; (iii) 75-84 years; and (iv) ≥85 years. Patient, event and treatment characteristics were examined for patients with presumed cardiac etiology of OHCA. The primary outcome was the 1-month survival with a neurologically favorable outcome. RESULTS: A total of 4636 patients with OHCA of presumed cardiac origin were transported to tertiary emergency medical institutions. The number of patients in the four groups was as follows: (i) 1290 (27.8%); (ii) 1102 (23.8%); (iii) 1420 (30.6%); and (iv) 824 (17.8%). The 1-month survival with a neurologically favorable outcome was: (i) 207 (16.0%); (ii) 96 (8.7%); (iii) 60 (4.2%); and (iv) seven (0.85%). In a multivariate analysis for 1-month survival with a neurologically favorable outcome, increased age was a significant prognostic factor (≥85 years; adjusted odds ratio 0.08, 95% confidence interval 0.03-0.23) for poor outcomes. CONCLUSIONS: In this population, advanced age (≥85 years) was strongly associated with poor outcomes. Further discussion of policies directed at resuscitation of very elderly OHCA patients is required, considering limited medical resources and the rapidly aging population in Japan. Geriatr Gerontol Int 2019; 19: 1088-1095.


Subject(s)
Out-of-Hospital Cardiac Arrest/mortality , Out-of-Hospital Cardiac Arrest/therapy , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Emergency Service, Hospital , Female , Humans , Japan/epidemiology , Male , Middle Aged , Prospective Studies , Survival Rate , Tertiary Care Centers , Transportation of Patients , Urban Health , Young Adult
13.
J Org Chem ; 84(14): 9330-9338, 2019 Jul 19.
Article in English | MEDLINE | ID: mdl-31265292

ABSTRACT

Photoredox-catalyzed allylation of α-gem-difluorinated organohalides with allyl sulfones proceeded smoothly under visible light irradiation to give 4,4-difluoroalkenes in good yields. In the presence of catalytic Ru(bpy)3Cl2, Hantzsch ester, and diisopropylethylamine, the reaction was complete within 2 h. Using the same methodology, three-component cascade reactions to give 6,6-difluoroalkenes were carried out successfully.

14.
Resuscitation ; 143: 165-172, 2019 10.
Article in English | MEDLINE | ID: mdl-31302105

ABSTRACT

OBJECTIVES: This study aimed to evaluate whether intra-aortic balloon pump (IABP) use in nontraumatic out-of-hospital cardiac arrest (OHCA) patients who achieved return of spontaneous circulation (ROSC) is associated with favorable neurological outcome after OHCA. BACKGROUND: The association between the IABP use in OHCA patients and favorable neurological outcome has not been extensively evaluated. METHODS: The Comprehensive Registry of Intensive Cares for OHCA Survival (CRITICAL) study, a multicenter, prospective observational registry in Osaka, Japan, included consecutive nontraumatic OHCA patients aged ≥18 years who achieved ROSC from July 2012 to December 2016. The primary outcome was 1-month survival with favorable neurological outcome. Logistic regression analysis was used to evaluate the association between the IABP use or non-IABP use and favorable neurological outcome using one-to-one propensity score (PS) matching analysis. RESULTS: Among the 2894 eligible patients, 10.4% used IABP, and 89.6% did not use IABP. In all patients, the proportion of 1-month survival with favorable neurological outcome was higher in the IABP use group than in the non-IABP use group (30.7% [92/300] vs. 13.2% [342/2594]). However, in PS-matched patients, the proportions of 1-month survival with favorable neurological outcome were almost consistent, and there were no significant differences between the IABP use group and the non-IABP use group (37.3% [59/158] vs. 41.1% [65/158]; adjusted odds ratio, 0.97; 95% confidence interval, 0.48-1.96). CONCLUSIONS: In this population, the current PS matching analysis did not reveal any association between the IABP use and 1-month survival with favorable neurological outcome among adult patients with ROSC after OHCA.


Subject(s)
Cardiopulmonary Resuscitation/methods , Intra-Aortic Balloon Pumping/methods , Out-of-Hospital Cardiac Arrest/therapy , Propensity Score , Registries , Aged , Female , Follow-Up Studies , Humans , Japan/epidemiology , Male , Middle Aged , Out-of-Hospital Cardiac Arrest/diagnosis , Out-of-Hospital Cardiac Arrest/mortality , Prospective Studies , Survival Rate/trends
15.
Resuscitation ; 133: 82-87, 2018 12.
Article in English | MEDLINE | ID: mdl-30316953

ABSTRACT

BACKGROUND: It has been insufficiently investigated whether neurological function after out-of-hospital cardiac arrest (OHCA) would differ by 1 °C change in ordered target temperature of 33-36 °C among patients undergoing targeted temperature management (TTM) in the real-world setting. METHODS: This nationwide hospital-based observational study (The Japanese Association for Acute Medicine-OHCA Registry) conducted between June 2014 and December 2015 in Japan included OHCA patients aged ≥18 years who were treated with TTM. The primary outcome was one-month survival with neurologically favorable outcomes defined by cerebral performance category 1 or 2. To investigate the effect of TTM by 1 °C change in ordered target temperature of 33-36 °C on each outcome, random effects logistic regression analyses were performed. RESULTS: The final analysis included 738 patients. The proportion of patients with neurologically favorable outcome was 30.4% (7/23), 31.7% (175/552), 28.9% (11/38), and 30.4% (38/125) in the 33 °C, 34 °C, 35 °C, and 36 °C groups, respectively. In the multivariable logistic regression analysis, no group had a higher proportion of neurologically favorable outcome compared with the 34 °C group (vs. 33 °C group, adjusted odds ratio [AOR] 0.90; 95% confidence interval [CI] 0.25-3.12, vs. 35 °C group, AOR 1.17; 95% CI 0.44-3.13, vs. 36 °C group, AOR 1.26; 95% CI 0.78-2.02). CONCLUSIONS: In this population, we evaluated the difference in outcomes after adult OHCA patients received TTM by 1 °C change in ordered target temperature of 33-36 °C and demonstrated that there was no statistically significant difference in neurologically favorable outcomes after OHCA irrespective of target temperature.


Subject(s)
Hypothermia, Induced/methods , Out-of-Hospital Cardiac Arrest/therapy , Outcome Assessment, Health Care/statistics & numerical data , Temperature , Adult , Aged , Cardiopulmonary Resuscitation/methods , Female , Humans , Japan , Logistic Models , Male , Middle Aged , Out-of-Hospital Cardiac Arrest/epidemiology , Registries , Retrospective Studies
16.
J Org Chem ; 82(10): 5469-5474, 2017 05 19.
Article in English | MEDLINE | ID: mdl-28472881

ABSTRACT

Photoredox-catalyzed hydrodifluoroalkylation of alkenes proceeded smoothly in the presence of a Hantzsch ester as a hydrogen source under visible light irradiation. The reaction was also applicable to the hydrodifluoroalkylation of alkynes, and a continuous photo flow reaction was also successful.

17.
Ann Vasc Dis ; 7(3): 256-60, 2014.
Article in English | MEDLINE | ID: mdl-25298826

ABSTRACT

OBJECTIVE: To our knowledge, no previous study has described the measurement of the tensile strength of the human aortic adventitia. In the present study, we examined the relationship between the tension and length of the aortic adventitia resected from the aortic wall of patients with acute aortic dissection. METHODS: We obtained rectangular specimens from the aortic adventitia that was resected in patients with acute aortic dissection during surgery. The specimens were placed on a tension meter (Digital Force Gauge FGS-10, SHIMPO, Kyoto, Japan) within 15 min after resection and stretched until they were pulled apart, and the tension and length were recorded. RESULTS: We obtained 18 specimens during surgery from 11 cases of acute aortic dissection. When the specimen was being pulled apart, the mean tension recorded was 10.2 ± 4.9 N/cm specimen width, whereas the mean elongated length recorded was 4.2 ± 1.1 mm/cm specimen length. DISCUSSION: We determined that the aortic adventitia is elastic and expandable up to 140% of its original length. This indicates that dilation of the aorta to >4.2 cm in diameter may result in a rupture if the original aortic diameter prior to dissection was 3 cm. (English translation of J Jpn Coll Angiol 2013; 53: 77-81).

18.
Biol Pharm Bull ; 32(9): 1584-7, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19721236

ABSTRACT

Taurine is contained in seafood and has been studied extensively on life-style related diseases. Theanine increased the effects of the doxorubicin (DOX) as an antitumor agent in some tumors and enhanced the DOX level in tumor cells. It is expected that the advanced effect of food uptake in cancer chemotherapy may be effective from the viewpoint of quality of life (QOL) improvement, although this approach has not been investigated in detail. In this study, the effect of taurine as a functional amino acid was examined. Taurine did not change the DOX influx into M5076 cells, whereas it significantly inhibited DOX efflux, which maintained the DOX level in tumor cells. Furthermore, experiments with taurine decreased tumor weight by 40%, compared to the DOX-alone group and significantly increased its antitumor effect. Moreover, as taurine did not increase DOX concentration in normal tissue, it is suggested that it increased the antitumor effect without enhancing DOX-induced adverse effects. DOX efflux is inhibited by beta-alanine as a taurine transporter inhibitor, therefore, enhancement of the DOX level by taurine was suggested to act via taurine transport. Namely, it was clarified that taurine was useful as a modulator to enhance the therapeutic index of cancer patients and improve QOL.


Subject(s)
Antineoplastic Agents/metabolism , Antineoplastic Agents/therapeutic use , Doxorubicin/metabolism , Doxorubicin/therapeutic use , Neoplasms/drug therapy , Neoplasms/metabolism , Taurine/physiology , Taurine/therapeutic use , Animals , Cell Line, Tumor , Drug Synergism , Humans , Male , Membrane Glycoproteins/antagonists & inhibitors , Membrane Glycoproteins/metabolism , Membrane Transport Proteins/metabolism , Mice , Mice, Inbred C57BL , Quality of Life , Taurine/metabolism
19.
Acta Histochem Cytochem ; 42(4): 121-8, 2009 Aug 29.
Article in English | MEDLINE | ID: mdl-19759873

ABSTRACT

The regulation of cytosolic Ca(2+) homeostasis is essential for cells, including vascular smooth muscle cells. Arterial tone, which underlies the maintenance of peripheral resistance in the circulation, is a major contributor to the control of blood pressure. Diuretics may regulate intracellular Ca(2+) concentration ([Ca(2+)](i)) and have an effect on vascular tone. In order to investigate the influence of diuretics on peripheral resistance in circulation, we investigated the alteration of [Ca(2+)](i) in testicular arterioles with respect to several categories of diuretics using real-time confocal laser scanning microscopy. In this study, hydrochlorothiazide (100 microM) and furosemide (100 microM) had no effect on the [Ca(2+)](i) dynamics. However, when spironolactone (300 microM) was applied, the [Ca(2+)](i) of smooth muscles increased. The response was considerably inhibited under either extracellular Ca(2+)-free conditions, the presence of Gd(3+), or with a treatment of diltiazem. After the thapsigargin-induced depletion of internal Ca(2+) store, the spironolactone-induced [Ca(2+)](i) dynamics was slightly inhibited. Therefore, the spironolactone-induced dynamics of [Ca(2+)](i) can be caused by either a Ca(2+) influx from extracellular fluid or Ca(2+) mobilization from internal Ca(2+) store, with the former being dominant. As tetraethylammonium, an inhibitor of the K(+) channel, slightly inhibited the spironolactone-induced [Ca(2+)](i) dynamics, the K(+) channel might play a minor role in those dynamics. Tetrodotoxin, a neurotoxic Na(+) channel blocker, had no effect, therefore the spironolactone-induced dynamics is a direct effect to smooth muscles, rather than an indirect effect via vessel nerves.

20.
Arch Histol Cytol ; 71(4): 235-47, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19359806

ABSTRACT

Dipyridamole, an inhibitor of adenosine uptake as well as a cGMP phosphodiesterase inhibitor, is commonly used in prophylactic therapy for patients with angina pectoris. However, the effects of dipyridamole on systemic blood vessels, especially on the peripheral vascular system, are not well understood. Therefore, the effect of dipyridamole on ATP-induced arteriole contraction was examined with special reference to intracellular Ca(2+) concentration ([Ca(2+)](i)) using real-time confocal microscopy. In cases of 0.1-10microM range, dipyridamole induced only slight [Ca(2+)](i) decreases in smooth muscle cells of both testicular and cerebral arterioles. However, 100microM dipyridamole induced substantial [Ca(2+)](i) decreases in the cells. In the presence of 10microM dipyridamole, changes in ATP-induced [Ca(2+)](i) were found to be inhibited in smooth muscle cells of testicular arterioles but not in those of cerebral arterioles. In addition, alpha, beta-methylene ATP-induced [Ca(2+)](i) increases in testicular arteriole smooth muscle cells were also partially inhibited in the presence of dipyridamole. When testicular arterioles were perfused with dipyridamole, no increases in nitric oxide levels were detected. High levels of K(+) induced a [Ca(2+)](i) increase in testicular arterioles that was also partially inhibited by dipyridamole. In the presence of substances that affect protein kinase A or G, ATP-induced [Ca(2+)](i) was not completely inhibited. These findings suggest that dipyridamole may act not only as an inhibitor of adenosine uptake and as a cGMP phosphodiesterase inhibitor, but also as a calcium channel blocker in arteriole smooth muscle cells.


Subject(s)
Arterioles/drug effects , Calcium Signaling/drug effects , Calcium/metabolism , Dipyridamole/pharmacology , Myocytes, Smooth Muscle/drug effects , Animals , Male , Myocytes, Smooth Muscle/ultrastructure , Rats , Rats, Inbred BB , Testis/blood supply , Testis/cytology
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