scholarly journals Effects of ischemic preconditioning on contractile and metabolic function during hypoperfusion in dogs

1998 ◽  
Vol 274 (2) ◽  
pp. H684-H693 ◽  
Author(s):  
Tetsuo Minamino ◽  
Masafumi Kitakaze ◽  
Hiroshi Sato ◽  
Hiroharu Funaya ◽  
Yasunori Ueda ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Preconditioning ◽  
Myocardial Metabolism ◽  
Contractile Function ◽  
Venous Blood ◽  
Control Group ◽  
Contractile Parameters ◽  
Blood Flow Ratio ◽  
Induced Changes ◽  
Fractional Shortening

We examined the effects of ischemic preconditioning (IP) on metabolic and contractile function during coronary hypoperfusion in dogs. After the left anterior descending coronary artery (LAD) was occluded for 5 min (IP) and reperfused for 10 min, coronary blood flow (CBF) of the LAD was decreased to 33% of the control. IP increased ( P < 0.05) lactate extraction ratio and the pH of coronary venous blood and decreased ( P < 0.05) myocardial oxygen consumption and fractional shortening during hypoperfusion compared with those in the control group, although IP did not change the endocardial-to-epicardial blood flow ratio of the regional myocardium during hypoperfusion. IP increased ( P< 0.05) the adenosine levels in coronary venous blood during hypoperfusion. IP increased ( P< 0.05) myocardial ecto-5′-nucleotidase activity. Administration of 8-sulfophenyltheophylline or α,β-methyleneadenosine 5′-diphosphate blunted the IP-induced changes in metabolic and contractile parameters during hypoperfusion. These results suggest that IP reduced the severity of anaerobic myocardial metabolism of ischemic hearts by increasing the adenosine levels via an extracellular pathway.

scholarly journals Changes in lower extremity blood flow during advancing phases of pregnancy and the effects of special footwear

2017 ◽  
Vol 16 (3) ◽  
pp. 214-219 ◽  
Author(s):  
Marta Gimunová ◽  
Martin Zvonař ◽  
Kateřina Kolářová ◽  
Zdeněk Janík ◽  
Ondřej Mikeska ◽  
...  
Keyword(s):  
Blood Flow ◽  
Venous Blood ◽  
Cross Sectional Area ◽  
Popliteal Vein ◽  
Control Group ◽  
Venous Disease ◽  
Venous Blood Flow ◽  
Sectional Area ◽  
Cross Sectional ◽  
Experimental Group

Abstract Background During pregnancy, a number of changes affecting venous blood flow occur in the circulatory system, such as reduced vein wall tension or increased exposure to collagen fibers. These factors may cause blood stagnation, swelling of the legs, or endothelial damage and consequently lead to development of venous disease. Objectives The aim of this study is to evaluate the effect of special footwear designed to improve blood circulation in the feet on venous blood flow changes observed during advancing phases of pregnancy. Methods Thirty healthy pregnant women participated in this study at 25, 30, and 35 weeks of gestation. Participants were allocated at random to an experimental group (n = 15) which was provided with the special footwear, or a control group (n = 15). At each data collection session, Doppler measurements of peak systolic blood flow velocity and cross-sectional area of the right popliteal vein were performed using a MySonoU6 ultrasound machine with a linear transducer (Samsung Medison). The differences were compared using Cohen’s d test to calculate effect size. Results With advancing phases of pregnancy, peak systolic velocity in the popliteal vein decreased significantly in the control group, whereas it increased significantly in the experimental group. No significant change in cross-sectional area was observed in any of the groups. Conclusions Findings in the experimental group demonstrated that wearing the footwear tested may prevent venous blood velocity from reducing during advanced phases of pregnancy. Nevertheless, there is a need for further investigation of the beneficial effect on venous flow of the footwear tested and its application.

Myocardial bioenergetics during acute hibernation

1997 ◽  
Vol 273 (3) ◽  
pp. H1452-H1463 ◽  
Author(s):  
J. Zhang ◽  
Y. Ishibashi ◽  
Y. Zhang ◽  
M. H. Eijgelshoven ◽  
D. J. Duncker ◽  
...  
Keyword(s):  
Blood Flow ◽  
Contractile Function ◽  
Creatine Phosphate ◽  
Wall Thickening ◽  
Resonance Spectroscopy ◽  
Blood Flow Ratio ◽  
Ischemic Period ◽  
Myocardial O2 Consumption ◽  
Final Extent ◽  
Myocardial Bioenergetics

During moderate reductions of blood flow, the myocardium downregulates contractile function and ATP utilization to result in reduced but stable ATP levels, recovery or stability of (reduced) creatine phosphate (CP), and preservation of myocyte viability. The intent of this study was to determine the influence of the level of ischemic blood flow and the major determinants of myocardial O2 consumption (MVO2) (heart rate and systolic blood pressure) on recovery of CP during prolonged moderate myocardial hypoperfusion. 31P-nuclear magnetic resonance spectroscopy was used to measure CP, ATP, and Pi in the subepicardium (Epi) and subendocardium (Endo) of 13 open-chest dogs. Wall thickening was measured with sonomicrometry. A coronary stenosis reduced mean myocardial blood flow (microspheres) from 1.10 +/- 0.07 to 0.71 +/- 0.06 ml.g-1.min-1 (P < 0.01) and the Endo-to-Epi blood flow ratio from 1.12 +/- 0.07 to 0.59 +/- 0.06 (P < 0.01), and dyskinesis developed. Coronary blood flow and systolic wall thickening did not change significantly during 4 h of hypoperfusion. Epi CP and ATP fell to 80 +/- 4% (P < 0.05) and 93 +/- 3% of control, respectively, at 30 min. Epi CP then recovered to 87 +/- 5% while ATP decreased further to 83 +/- 5% of baseline by the end of the 240-min ischemic period. Endo CP and ATP fell to 53 +/- 4 and 77 +/- 5% of control, respectively, at 30 min; then Endo CP recovered to 85 +/- 6% while ATP decreased further to 68 +/- 6% of baseline at 240 min of hypoperfusion. ADP levels were significantly increased at 30 min but recovered to baseline by 240 min of hypoperfusion. delta Pi/CP increased significantly (Endo > Epi) at the onset of ischemia and then progressively decreased. At 30 min, mild myocardial acidosis was observed in some hearts with variable pH recovery during continuing hypoperfusion. The data demonstrate that variations in blood flow cannot account for the magnitude of the initial fall in CP or for the final extent of recovery. However, the rate at which CP recovered was significantly correlated with the level of blood flow. Variations in the determinants of MVO2 did not account for differences in CP recovery.

Potential role of electrostimulation in augmentation of venous blood flow after total knee replacement: A pilot study

2015 ◽  
Vol 31 (4) ◽  
pp. 251-256 ◽  
Author(s):  
Seyhan Yilmaz ◽  
Murat Calbiyik ◽  
Behice Kaniye Yilmaz ◽  
Eray Aksoy
Keyword(s):  
Blood Flow ◽  
Total Knee Replacement ◽  
Knee Replacement ◽  
Femoral Vein ◽  
Venous Blood ◽  
Control Group ◽  
Venous Blood Flow ◽  
Female Ratio ◽  
Total Knee ◽  
Peak Blood

Aim To investigate the potential role of a novel electrostimulation device in augmenting the femoral vein venous blood flow following total knee replacement surgery. Material and methods A total of 30 consecutive patients undergoing total knee replacement were allocated to receive either peroneal nerve electrostimulation plus low molecular weight heparin and below-knee compression stockings (Group 1, electrostimulation group, n = 15, mean age: 63.40 ± 5.91 years, male: female ratio 9:6) or low molecular weight heparin and below-knee compression stockings alone (Group 2, control group, n = 15, mean age: 63.86 ± 7.47 years, male: female ratio 8:7). Electrostimulation was performed for 1 h in every 4 h after the operation. Peak blood velocity in the femoral vein was evaluated with Duplex ultrasonongraphy in supine position. Presence of leg edema and calf diameter was also taken into consideration as outcome measures, which were recorded both before surgery and at the time of discharge from hospital. Results Postoperative peak blood flow velocity in the femoral vein was significantly higher in electrostimulation group compared to control group (17.46 ± 2.86 cm/s vs. 13.84 ± 3.58 cm/s, p < 0.02). Electrostimulation group achieved a significant increase in peak blood flow velocity in the femoral vein after the operation (mean increase 67.48 ± 17.38%, p < 0.001). Conclusion Electrostimulation of the common peroneal nerve enhanced venous flow in the lower limb and may potentially be of use as a supplementary technique in deep venous prophylaxis following lower limb orthopedic operations.

Prolonged transient acidosis during early reperfusion contributes to the cardioprotective effects of postconditioning

2007 ◽  
Vol 292 (4) ◽  
pp. H2004-H2008 ◽  
Author(s):  
Masashi Fujita ◽  
Hiroshi Asanuma ◽  
Akio Hirata ◽  
Masakatsu Wakeno ◽  
Hiroyuki Takahama ◽  
...  
Keyword(s):  
Blood Flow ◽  
Infarct Size ◽  
Venous Blood ◽  
Ischemic Myocardium ◽  
Control Group ◽  
Collateral Blood Flow ◽  
Area At Risk ◽  
Early Reperfusion ◽  
Cardioprotective Effects ◽  
Reperfusion Phase

We have previously reported that the prolonged transient acidosis during early reperfusion mediates the cardioprotective effects in canine hearts. Recently, postconditioning has been shown to be one of the novel strategies to mediate cardioprotection. We tested the contribution of the prolonged transient acidosis to the cardioprotection of postconditioning. Open-chest anesthetized dogs subjected to 90-min occlusion of the left anterior descending coronary artery and 6-h reperfusion were divided into four groups: 1) control group; no intervention after reperfusion ( n = 6); 2) postconditioning (Postcon) group; four cycles of 1-min reperfusion and 1-min reocclusion ( n = 7); 3) Postcon + sodium bicarbonate (NaHCO3) group; four cycles of 1-min reperfusion and 1-min reocclusion with the administration of NaHCO3( n = 8); and 4) NaHCO3group; administration of NaHCO3without postconditioning ( n = 6). Infarct size, the area at risk (AAR), collateral blood flow during ischemia, and pH in coronary venous blood were measured. The phosphorylation of Akt and extracellular signal-regulated kinase (ERK) in ischemic myocardium was assessed by Western blot analysis. Systemic hemodynamic parameters, AAR, and collateral blood flow were not different among the four groups. Postconditioning induced prolonged transient acidosis during the early reperfusion phase. Administration of NaHCO3completely abolished the infarct size-limiting effects of postconditioning. Furthermore, the phosphorylation of Akt and ERK in ischemic myocardium induced by postconditioning was also blunted by the cotreatment of NaHCO3. In conclusion, postconditioning mediates its cardioprotective effects possibly via prolonged transient acidosis during the early reperfusion phase with the activation of Akt and ERK.

scholarly journals CO2 clearance by membrane lungs

Perfusion ◽  
2017 ◽  
Vol 33 (4) ◽  
pp. 249-253 ◽  
Author(s):  
Liqun Sun ◽  
Andreas Kaesler ◽  
Piyumindri Fernando ◽  
Alex J. Thompson ◽  
John M. Toomasian ◽  
...  
Keyword(s):  
Blood Flow ◽  
Surface Area ◽  
Oxygen Transfer ◽  
Venous Blood ◽  
Venous Blood Flow ◽  
Flow Ratio ◽  
Removal Capacity ◽  
Blood Flow Ratio ◽  
Specific Amount

Introduction: Commercial membrane lungs are designed to transfer a specific amount of oxygen per unit of venous blood flow. Membrane lungs are much more efficient at removing CO2 than adding oxygen, but the range of CO2 transfer is rarely reported. Methods: Commercial membrane lungs were studied with the goal of evaluating CO2 removal capacity. CO2 removal was measured in 4 commercial membrane lungs under standardized conditions. Conclusion: CO2 clearance can be greater than 4 times that of oxygen at a given blood flow when the gas to blood flow ratio is elevated to 4:1 or 8:1. The CO2 clearance was less dependent on surface area and configuration than oxygen transfer. Any ECMO system can be used for selective CO2 removal.

Jejunal adenosine increases during food-induced jejunal hyperemia

1990 ◽  
Vol 258 (3) ◽  
pp. G370-G376 ◽  
Author(s):  
D. R. Sawmiller ◽  
C. C. Chou
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Normal Saline ◽  
Venous Blood ◽  
Adenosine Release ◽  
Adenosine Concentration ◽  
Anesthetized Dogs ◽  
Arterial Plasma ◽  
Induced Changes ◽  
Increased Blood Flow

If adenosine mediates postprandial intestinal hyperemia, increases in local adenosine release must accompany the hyperemia. We tested this by determining jejunal venous and arterial plasma adenosine concentrations, jejunal blood flow, and oxygen consumption before and during placement of normal saline or predigested food plus bile into the jejunal lumen of anesthetized dogs. Adenosine concentrations were measured by high-pressure liquid chromatography. Luminal placement of food significantly increased blood flow (+46%), oxygen consumption (+40%), venous adenosine concentration (+56 nM), and adenosine release (+1.7 nmol.min-1.100 g tissue-1) during the initial 3 min of placement. Whereas blood flow and oxygen consumption remained elevated for the entire 15-min placement period, venous adenosine concentration and release returned to control levels at 7 and 11 min after placement, respectively. Placement of the same volume of normal saline did not significantly alter any variables measured, indicating that the food-induced changes were because of constituents of food. In conclusion, introduction of predigested food into the jejunal lumen significantly increases adenosine releases into the local venous blood during the initial several minutes of food placement. The increased adenosine production and release may play a role in postprandial jejunal hyperemia.

scholarly journals Peculiarities of the reaction of the lower limbs venous blood flow to the orthostatic test in men with arterial hypertension

2019 ◽  
pp. 86-89
Author(s):  
T. F. Vagapov ◽  
V. M. Baev ◽  
S. V. Letyagina
Keyword(s):  
Blood Flow ◽  
Arterial Hypertension ◽  
Flow Rate ◽  
Femoral Vein ◽  
Venous Blood ◽  
Test Group ◽  
Blood Flow Rate ◽  
Lower Limbs ◽  
Control Group ◽  
Venous Blood Flow

A comparative analysis of the dynamics of lower limb vein angioscopy parameters in case of orthostasis between male patients (age 30–50 years) with arterial hypertension (test group – 60 people) and normal arterial pressure (control group – 27 people) was made. Orthostatic sample in all examined patients was characterized by a reliable increase in the diameter and area of vein section at a decrease in blood flow rate. However, in patients with hypertension the increase in the area of vein section was significantly less than in the control group. In orthostasis, the drop in blood flow rate in the total femoral vein was lower in men with hypertension than in men in the control group. In the great saphenous vein, a larger decrease in blood flow velocity was recorded than in the control group. In hypertension, no increase in the number of refluxes was recorded in orthostasis. Thus, hypertension in men is characterized by altered reaction of venous blood flow to orthostasis in both deep and saphenous veins.

Effect of ischemia-reperfusion on diaphragm strength and fatigability

1993 ◽  
Vol 75 (5) ◽  
pp. 2180-2187 ◽  
Author(s):  
G. Supinski ◽  
D. Stofan ◽  
A. DiMarco
Keyword(s):  
Blood Flow ◽  
Free Radical ◽  
Contractile Function ◽  
Contractile Activity ◽  
Ischemia Reperfusion ◽  
Free Radical Scavenger ◽  
Control Group ◽  
Radical Scavenger ◽  
Force Frequency ◽  
Frequency Relationship

Although episodes of prolonged limb skeletal muscle ischemia followed by periods of reperfusion and reoxygenation are known to elicit free radical-mediated injury, the susceptibility of the diaphragm to this form of injury is not known. The purpose of the present study was to determine the effects of a period of severe partial ischemia, followed by reperfusion, on diaphragm contractile function. We also examined the effect of administration of a free radical scavenger, dimethyl sulfoxide (DMSO), on the diaphragmatic response to ischemia-reperfusion. Experiments were performed on three groups of anesthetized dogs in which a vascularly isolated strip of diaphragm was dissected in situ: 1) a control group in which the diaphragm was perfused at the ambient systemic pressure, 2) a group in which the diaphragm was made ischemic for 3 h and reperfused for 1 h, and 3) a group given DMSO before periods of ischemia and reperfusion. In all groups, we measured diaphragm strip strength and fatigability; we also assessed diaphragm blood flow at several levels of contractile activity. Periods of ischemia, followed by reperfusion, were found to produce a downward shift of the diaphragm force-frequency relationship and also to markedly increase diaphragm fatigability. Diaphragm blood flow at rest and at low levels of contractile activity was unaffected by ischemia-reperfusion, but the flow achieved during fatiguing contractions was appreciably lower than that in nonischemic control animals. DMSO administration protected the diaphragm from the effects of ischemia-reperfusion, preventing alterations in fatigability and strength. Diaphragm flow in DMSO-treated animals was similar to that in controls.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Mitochondrial antioxidant plastomitin alters the myocardial energy state and prevented the development of systolic dysfunction in doxorubicin-induced cardiomyopathy

2020 ◽  
pp. 24-30
Author(s):  
В.Л. Лакомкин ◽  
И.М. Студнева ◽  
А.А. Абрамов ◽  
А.В. Просвирнин ◽  
О.М. Веселова ◽  
...  
Keyword(s):  
Ejection Fraction ◽  
Mitochondrial Respiration ◽  
Contractile Function ◽  
Adenine Nucleotide ◽  
Heart Function ◽  
Energy State ◽  
Systolic Dysfunction ◽  
Control Group ◽  
Adenine Nucleotide Pool ◽  
Fractional Shortening

Резюме Цель исследования. Настоящая работа предпринята с целью изучения влияния митохондриального антиоксиданта пластомитина (ПМ, препарат SkQ1) на энергетическое состояние и функцию сердца крыс с кардиомиопатией, вызванной введением доксорубицина (Докс). Материалы и методы. Использовали крыс-самцов Вистар, которым вводили подкожно Докс (2 мг/кг/нед.) в течение 5 недель (группа Докс). Животным группы Докс+ПМ наряду с доксорубицином 5 недель подкожно вводили ПМ в дозе 0,32 мг/кг ежедневно. Контрольной группе животных в течение 5 недель вводили такой же объем физиологического раствора. Перед началом введения препаратов и через 8 недель у всех крыс была выполнена эхокардиография (ЭхоКГ) левого желудочка (ЛЖ). Дополнительно у части животных была изучена сократительная функция ЛЖ при помощи PV-катетера. Содержание адениннуклеотидов (АТФ, АДФ и АМФ), фосфокреатина (ФКр), креатина (Кр) и лактата в безбелковых экстрактах сердец определяли энзиматическими методами. Дыхание митохондрий в скинированных сапонином волокнах ЛЖ определяли полярографическим методом. Результаты. В конце исследования у животных группы Докс фракция выброса и фракция укорочения были достоверно снижены, а диастолический объём ЛЖ уменьшен по сравнению с этими показателями в контрольной группе. В группе Докс+ПМ фракция выброса, фракция укорочения, индекс сократимости миокарда, максимальная скорость развития давления и работа сердца были выше, чем в группе Докс и недостоверно отличались от величин в контроле. Эти изменения сочетались с достоверным увеличением содержания общего фонда адениннуклеотидов и креатина в сердце животных группы Докс+ПМ по сравнению с этими показателями у животных, получавших только Докс. Показатели скорости дыхания митохондрий в волокнах ЛЖ, выделенных из сердец животных группы Докс+ПМ, были выше, чем в группе Докс. Заключение. Применение ПМ предотвращало развитие систолической дисфункции у животных, получавших Докс. Это было связано с улучшением окислительного фосфорилирования и сохранением фонда адениннуклеотидов в сердце Summary Aim. This study was designed to explore effects of the mitochondrial antioxidant plastomitin (PM) on the energy state and heart function of rats with cardiomyopathy induced by doxorubicin (Dox) administration. Material and methods. Male Wistar rats were injected subcutaneously with Dox (2 mg / kg / weekly) for 5 weeks (Dox group). Animals of the Dox + PM group were subcutaneously injected with PM for 5 weeks at a dose of 0.32 mg/kg daily along with Dox. The control group of animals was injected for 5 weeks with the same volume of saline. Before the administration of drugs and after 8 weeks of the study, all rats were underwented echocardiography of the left ventricle (LV). Additionally, the LV contractile function was studied using a PV catheter in some animals. The contents of adenine nucleotides (ATP, ADP and AMP), phosphocreatine (PCr), creatine (Cr) and lactate in protein-free extracts of hearts were determined by enzymatic methods. Mitochondrial respiration in saponin-skinned LV fibers was determined using the polarographic method. Results. At the end of the study, in animals of Dox group, the ejection fraction, fractional shortening and LV diastolic volume were significantly reduced in comparison with these indices in the control group. In Dox + PM group, the ejection fraction, fractional shortening, myocardial contractility index, maximum rate of pressure development and heart work were significantly higher than in Dox group and did not differ from the control values. These functional alterations were combined with a significant increase in the content of myocardial adenine nucleotide pool and creatine in animals of Dox + PM group compared with these parameters in animals treated with Dox alone.The rate of mitochondrial respiration in LV fibers isolated from the hearts of animals of Dox + PM group was higher than in Dox group. Conclusion. Treatment with PM prevented the development of LV systolic dysfunction in animals received Dox. This beneficial effect was due to an improvement in oxidative phosphorylation and preservation of myocardial adenine nucleotide pool.

Sign in / Sign up

Export Citation Format

Share Document