An ATP-sensitive potassium channel blocker decreases diaphragmatic circulation in anesthetized dogs

1994 ◽  
Vol 77 (1) ◽  
pp. 127-134 ◽  
Author(s):  
A. Comtois ◽  
C. Sinderby ◽  
N. Comtois ◽  
A. Grassino ◽  
J. M. Renaud
Keyword(s):  
Blood Flow ◽  
Phrenic Nerve ◽  
Spontaneous Breathing ◽  
Arterial Blood Flow ◽  
Control Group ◽  
Transdiaphragmatic Pressure ◽  
K Channels ◽  
Arterial Blood ◽  
Tension Time ◽  
Experimental Group

The goal of this study was to determine whether in the dog ATP-sensitive K+ channels blocked with glibenclamide affect diaphragmatic blood flow [phrenic arterial blood flow (Qpa)] during both spontaneous breathing at rest and increased diaphragmatic activity. A control group (no glibenclamide; n = 4) and an experimental group (50 mg/kg of glibenclamide; n = 5) were studied. During spontaneous breathing at rest, Qpa was 15.0 ml.min-1 x 100 g-1 and decreased by 5% in the presence of glibenclamide. Diaphragmatic pacing (30 min-1) generated by phrenic nerve pacing produced an initial diaphragmatic tension-time index of 0.25 in both groups. A 50% decay in transdiaphragmatic pressure was reached at 165 s in the experimental group compared with 421 s in the control group. Diaphragmatic pacing increased Qpa by 46% in the experimental group and 65% in the control group, yielding a 63% greater vascular resistance in the experimental group. Phrenic vein K+ content at rest was unchanged by the presence of glibenclamide, being 3.6 +/- 0.16 mmol/l compared with 3.5 +/- 0.19 mmol/l in the control group. Phrenic nerve pacing in the control group produced a 13% increase in phrenic vein K+ content, whereas in the experimental group a 16% decrease was observed. We suggest that ATP-sensitive K+ channels play an important role in the modulation of Qpa.

Effect of separate hemidiaphragm contraction on left phrenic artery flow and O2 consumption

1990 ◽  
Vol 69 (1) ◽  
pp. 86-90 ◽  
Author(s):  
F. Hu ◽  
A. Comtois ◽  
E. Shadram ◽  
A. Grassino
Keyword(s):  
Blood Flow ◽  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Arterial Blood Flow ◽  
O2 Consumption ◽  
Phrenic Nerve Stimulation ◽  
Diaphragm Pacing ◽  
Transdiaphragmatic Pressure ◽  
Arterial Blood ◽  
Significant Difference

Phrenic arterial blood flow has been shown to increase during bilateral phrenic nerve stimulation (BPNS). However, the role of unilateral phrenic nerve stimulation [left (LPNS) or right (RPNS)] on the blood flow and O2 consumption of the contralateral hemidiaphragm is not known and is explored here. In six anesthetized, mechanically hyperventilated dogs, left phrenic arterial blood flow (Qlpha) was measured (Doppler technique). Supramaximal (10 V, 30 Hz, 0.25-ms duration) LPNS, RPNS, and BPNS at a pacing frequency 15/min and duty cycle of 0.50 were delivered in separate runs. Left hemidiaphragmatic blood samples for gas analyses were obtained by left phrenic venous cannulation. During RPNS, Qlpha and left hemidiaphragmatic O2 consumption (VO2ldi) did not change significantly compared with control. During LPNS and BPNS, there was a significant increase in Qlpha and VO2ldi (P less than 0.01). There was no significant difference in Qlpha and VO2ldi between LPNS and BPNS (P greater than 0.05). We conclude 1) that there is a complete independence of left-right hemidiaphragmatic circulation both at rest and during diaphragm pacing and 2) that during unilateral stimulation transdiaphragmatic pressure is not related to diaphragmatic blood flow.

scholarly journals EFFECT OF DIFFERENT OCCLUSION PRESSURE ON PECULIARITIES OF MUSCLE BLOOD FLOW

2018 ◽  
Vol 1 (108) ◽  
pp. 2-8
Author(s):  
Kęstutis Bunevičius ◽  
Albinas Grunovas ◽  
Jonas Poderys
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Arterial Blood Pressure ◽  
Arterial Blood Flow ◽  
Control Group ◽  
Reactive Hyperaemia ◽  
Occlusion Pressure ◽  
Arterial Blood ◽  
Flow Intensity ◽  
Blood Flow Intensity

Background. Occlusion pressure intensity influences the blood flow intensity. Immediately after the cuff pressure is released, reactive hyperaemia occurs. Increased blood flow and nutritive delivery are critical for an anabolic stimulus, such as insulin. The aim of study was to find which occlusion pressure was optimal to increase the highest level of post occlusion reactive hyperaemia. Methods. Participants were randomly assigned into one of the four conditions (n = 12 per group): control group without blood flow restriction, experimental groups with 120; 200 or 300 mmHg occlusion pressure. We used venous occlusion plethysmography and arterial blood pressure measurements. Results. After the onset of 120 and 200 mm Hg pressure occlusion, the blood flow intensity significantly decreased. Occlusion induced hyperaemia increased arterial blood flow intensity 134 ± 11.2% (p < .05) in the group with 120 mmHg, in the group with 200 mmHg it increased 267 ± 10.5% (p < .05), in the group with 300 mmHg it increased 233 ± 10.9% (p < .05). Applied 300 mmHg occlusion from the 12 minute diastolic and systolic arterial blood pressure decreased statistically significantly. Conclusions. Occlusion manoeuvre impacted the vascular vasodilatation, but the peak blood flow registered after occlusion did not relate to applied occlusion pressure. The pressure of 200 mmHg is optimal to impact the high level of vasodilatation. Longer than 12 min 300 mmHg could not be recommended due to the steep decrease of systolic and diastolic blood pressures.

scholarly journals EFFICACY OF FREE AUTOVENOUS TRANSPLANT IN FEMORAL-POPLITEAL BYPASS BELOW THE JOINT SPACE OF THE KNEE

2016 ◽  
Vol 175 (4) ◽  
pp. 75-79
Author(s):  
B. S. Sykovatykh ◽  
L. N. Belikov ◽  
M. B. Sykovatykh ◽  
D. V. Sidorov ◽  
M. A. Inarkhov ◽  
...  
Keyword(s):  
Blood Flow ◽  
Joint Space ◽  
Arterial Blood Flow ◽  
Control Group ◽  
Treatment Technology ◽  
Critical Ischemia ◽  
Shunt Thrombosis ◽  
Atherosclerotic Lesions ◽  
Arterial Blood

The article presents an analysis of complex examination and treatment of 60 patients with critical ischemia of the lower extremities due to atherosclerotic lesions of femoral-poplitealtibia segment. Typical traditional autovenous bypass of reverse big saphena was performed for the first (control) group of patients. The operation, which used an original technology by free autovenous transplant with collapsed valves without vein reverse, was completed for the second (experimental) group of patients. An application of original treatment technology allowed an increase of blood flow volume in the extremity in 1,5 times, an arterial blood flow - in 1,6 times, rate of microcirculation - in 1,3 times. An early postoperative complications were decreased on 23,4%, the late shunt thrombosis - on 40%. Long-term shunt passability was improved in 2,6 times and physical component of health - on 10,6%, psychological - on 4,3%. The shunt functioned in 36,7% of the first group and in 83,3% patients of the second group after two years since operation. The extremity was saved in 60% of the first group and 90% patients of the second group.

BIOMECHANICAL, PHYSIOLOGICAL AND AGE-RELATED FEATURES OF PERSONIFICATION AND INDIVIDUALIZATION DURING QUICKNESS AND SPEED-STRENGTH QUALITIES ENHANCEMENT IN YOUNG WEIGHTLIFTERS

2019 ◽  
Vol 19 (3) ◽  
pp. 28-35 ◽  
Author(s):  
A Isaev ◽  
R Khomenko ◽  
A Nenasheva ◽  
A Shevtsov ◽  
A Batueva
Keyword(s):  
Blood Flow ◽  
Body Composition ◽  
Stroke Volume ◽  
Performance Enhancement ◽  
Diagnostic System ◽  
The Body ◽  
Control Group ◽  
Arterial Blood ◽  
Age Related ◽  
Experimental Group

Aim. The article deals with studying biomechanical, physiological, and age-related features in young weightlifters during quickness and speed-strength qualities enhancement. Materials and methods. The study was conducted at the precompetitive stage of preparation. Weightlifters aged 14–15 and 16–17 years (n = 15) participated in the experiment. Body composition was studied with the Tanita BC-418AA computer analyzer. The spatial characteristics of spine segments were investigated with the help of the MBN-Scanner computer equipment. Postural studies were conducted with the stabilometric systems produced by MBN Russia. Blood flow spectral analysis was performed using impedance rheography (the Centaur diagnostic system). Results. The body composition of young weightlifters was varied in the following range: muscle mass – 52.4–53.9%, fat mass – 9.0–10.2%. BMI was equal 25.64 kg/m2. The data of the orthostatic test in young weightlifters revealed significant changes in HR, total spectrum power (TSP), and stroke volume regulation (SV) in the experimental group (p < 0.05). In the control group, HR changes were higher than in the experimental group. In 50% of athletes from the groups of sports performance enhancement, eukinetic blood flow was revealed, in 32% – hypokinetic, and in 18% – hypertonic. After a year of training, a consistent increase in stroke volume (SV) was registered, as well as a decrease in HR, peripheral vascular resistance (PVR), heart index, and arterial blood pressure. Conclusion. The control system allows revealing in time the problems connected with weightlifters’ preparation, offering rehabilitation measures, and transforming the training process itself (its orientation, volume, intensity) to optimize body functioning in young weightlifters.

scholarly journals Exercise training improves vascular function in patients with Alzheimer’s disease

2020 ◽  
Vol 120 (10) ◽  
pp. 2233-2245
Author(s):  
Anna Pedrinolla ◽  
Massimo Venturelli ◽  
Cristina Fonte ◽  
Stefano Tamburin ◽  
Angela Di Baldassarre ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Blood Flow ◽  
Exercise Training ◽  
Vascular Function ◽  
Vascular Dysfunction ◽  
Area Under The Curve ◽  
Arterial Blood Flow ◽  
Control Group ◽  
Arterial Blood

Abstract Purpose Vascular dysfunction has been demonstrated in patients with Alzheimer’s disease (AD). Exercise is known to positively affect vascular function. Thus, the aim of our study was to investigate exercise-induced effects on vascular function in AD. Methods Thirty-nine patients with AD (79 ± 8 years) were recruited and randomly assigned to exercise training (EX, n = 20) or control group (CTRL, n = 19). All subjects performed 72 treatment sessions (90 min, 3 t/w). EX included moderate–high-intensity aerobic and strength training. CTRL included cognitive stimuli (visual, verbal, auditive). Before and after the 6-month treatment, the vascular function was measured by passive-leg movement test (PLM, calculating the variation in blood flow: ∆peak; and area under the curve: AUC) tests, and flow-mediated dilation (FMD, %). A blood sample was analyzed for vascular endothelial growth factor (VEGF). Arterial blood flow (BF) and shear rate (SR) were measured during EX and CTRL during a typical treatment session. Results EX group has increased FMD% (+ 3.725%, p < 0.001), PLM ∆peak (+ 99.056 ml/min, p = 0.004), AUC (+ 37.359AU, p = 0.037) and VEGF (+ 8.825 pg/ml, p = 0.004). In the CTRL group, no difference between pre- and post-treatment was found for any variable. Increase in BF and SR was demonstrated during EX (BF + 123%, p < 0.05; SR + 134%, p < 0.05), but not during CTRL treatment. Conclusion Exercise training improves peripheral vascular function in AD. These ameliorations may be due to the repetitive increase in SR during exercise which triggers NO and VEGF upregulation. This approach might be included in standard AD clinical practice as an effective strategy to treat vascular dysfunction in this population.

scholarly journals Influence Of 200 mm Hg Occlusion Pressure on Arterial Blood Flow in Skeletal Muscles and Physical Working Capacity

2018 ◽  
Vol 4 (87) ◽  
Author(s):  
Kęstutis Bunevičius ◽  
Albinas Grūnovas ◽  
Karolis Tijūnaitis
Keyword(s):  
Blood Flow ◽  
Skeletal Muscles ◽  
Arterial Blood Flow ◽  
Physical Working Capacity ◽  
Occlusion Pressure ◽  
Working Capacity ◽  
Arterial Blood ◽  
Flow Intensity ◽  
Experimental Group ◽  
Blood Flow Intensity

Research background and hypothesis. Different weights, resistance, scope of work, rest periods, frequency, and performance velocity are used to increase strength in training sessions. The traditional training facility with high resistance can be replaced by low resistance while limiting muscle blood flow. Hypothesis: a single 15-minute 200 mm Hg occlusion pressure can affect physical working capacity and blood flow intensity.Research  aim.  was  to  analyze  changes  in  the  intensity  of  the  calf  muscle  arterial  blood  flow  and  physical working capacity with and without 200 mm Hg pressure occlusion.   Research  methods.  were  dynamometry,  ergometry,  venous  occlusive  plethysmography.  The  control  group included six and experimental group – 12 male athletes in endurance sports. In both groups we recorded arterial blood flow at rest and after 75% of maximum voluntary contraction force (MVC) physical work lifting a weight until complete fatigue. Between the first and second physical workloads in the experimental group we applied 15 min occlusion with 40 mm wide cuff in the groin area.Research results. During the physical load in the control group, arterial blood flow significantly increased, and during recovery it did not reach to baseline. In the experimental group arterial blood flow significantly increased and during recovery it did not reach the baseline. Blood flow intensity both the first and the second physical loads altered analogically. Before the second physical load in the experimental group, 200 mm Hg occlusion had a negative effect on skeletal muscle working capacity compared with the passive rest in the control group.Discussion and conclusions. Occlusion of 200 mm Hg in the groin area reduces arterial blood flow intensity in calf skeletal muscles. Immediately after the removal of 200 mm Hg occlusion, arterial blood flow intensity increases and then decreases to its original value. 200 mm Hg occlusion pressure reduces blood flow intensity in the skeletal muscles.    Before  the  second  physical  load,  200  mm  Hg  occlusion  decreases  skeletal  muscle  working  capacity compared with passive rest in the control group.Keywords: occlusion, physical working capacity, arterial blood flow.

Modeling Elastic Walls in Lattice Boltzmann Simulations of Arterial Blood Flow

2013 ◽  
Vol 23 (2) ◽  
Author(s):  
Xenia Descovich ◽  
Giuseppe Pontrelli ◽  
Sauro Succi ◽  
Simone Melchionna ◽  
Manfred Bammer
Keyword(s):  
Blood Flow ◽  
Lattice Boltzmann ◽  
Arterial Blood Flow ◽  
Arterial Blood ◽  
Lattice Boltzmann Simulations ◽  
Elastic Walls

scholarly journals Sustained Inflation Reduces Pulmonary Blood Flow during Resuscitation with an Intact Cord

Children ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 353
Author(s):  
Jayasree Nair ◽  
Lauren Davidson ◽  
Sylvia Gugino ◽  
Carmon Koenigsknecht ◽  
Justin Helman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Perinatal Asphyxia ◽  
Arterial Blood Flow ◽  
Positive Pressure ◽  
Optimal Timing ◽  
Delayed Cord Clamping ◽  
Arterial Blood ◽  
Cord Clamping ◽  
Sustained Inflation ◽  
Near Term

The optimal timing of cord clamping in asphyxia is not known. Our aims were to determine the effect of ventilation (sustained inflation–SI vs. positive pressure ventilation–V) with early (ECC) or delayed cord clamping (DCC) in asphyxiated near-term lambs. We hypothesized that SI with DCC improves gas exchange and hemodynamics in near-term lambs with asphyxial bradycardia. A total of 28 lambs were asphyxiated to a mean blood pressure of 22 mmHg. Lambs were randomized based on the timing of cord clamping (ECC—immediate, DCC—60 s) and mode of initial ventilation into five groups: ECC + V, ECC + SI, DCC, DCC + V and DCC + SI. The magnitude of placental transfusion was assessed using biotinylated RBC. Though an asphyxial bradycardia model, 2–3 lambs in each group were arrested. There was no difference in primary outcomes, the time to reach baseline carotid blood flow (CBF), HR ≥ 100 bpm or MBP ≥ 40 mmHg. SI reduced pulmonary (PBF) and umbilical venous (UV) blood flow without affecting CBF or umbilical arterial blood flow. A significant reduction in PBF with SI persisted for a few minutes after birth. In our model of perinatal asphyxia, an initial SI breath increased airway pressure, and reduced PBF and UV return with an intact cord. Further clinical studies evaluating the timing of cord clamping and ventilation strategy in asphyxiated infants are warranted.

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