Circulatory and metabolic responses to carbon monoxide hypoxia during beta-adrenergic blockade

1988 ◽  
Vol 255 (1) ◽  
pp. H77-H84
Author(s):  
M. J. Melinyshyn ◽  
S. M. Cain ◽  
S. M. Villeneuve ◽  
C. K. Chapler
Keyword(s):  
Carbon Monoxide ◽  
Cardiac Output ◽  
Sampling Period ◽  
Whole Body ◽  
Metabolic Responses ◽  
Control Group ◽  
Adrenergic Blockade ◽  
Control Series ◽  
Ici 118,551 ◽  
Beta 2

The role(s) of beta-adrenoceptors in whole body and hindlimb skeletal muscle cardiovascular and metabolic responses during carbon monoxide hypoxia (COH) was studied in anesthetized dogs. One group of animals was beta-blocked with propranolol (beta 1- and beta 2-blockade), a second was given ICI 118,551 (beta 2-blockade), and a third served as a time control. Immediately after a control-sampling period, COH was induced (about a 63% decrease in arterial O2 content), and additional measurements were then obtained at 30 and 60 min of hypoxia. Cardiac output values were not different between the three series at control; an increase (P less than 0.05) occurred in all groups during COH. This rise was greatest in the COH group; the values for the propranolol- and ICI 118,551-blocked groups were not different from each other during COH. Hindlimb blood flow rose (P less than 0.05) during COH only in the control group. Both whole body (30 min) and hindlimb (30 and 60 min) resistance values were greater during hypoxia in the beta-blocked groups (P less than 0.05) than in the control series. Furthermore, whole body oxygen uptake decreased (P less than 0.05) in both beta-blocked groups during COH. We conclude that approximately 35% of the rise in cardiac output occurring during COH depended on peripheral vasodilation mediated through beta 2-adrenoceptors.

Metabolic and circulatory responses of normoxic skeletal muscle to whole-body hypoxia

1988 ◽  
Vol 65 (5) ◽  
pp. 2063-2068 ◽  
Author(s):  
D. L. Bredle ◽  
C. K. Chapler ◽  
S. M. Cain
Keyword(s):  
Perfusion Pressure ◽  
Muscle Blood Flow ◽  
Autologous Blood ◽  
Whole Body ◽  
Membrane Oxygenator ◽  
O2 Uptake ◽  
Ici 118,551 ◽  
Autoregulatory Escape ◽  
Beta 2 ◽  
O2 Supply

Whole-body hypoxia may increase peripheral O2 demand because it increases catecholamine calorigenesis, an effect attributable to beta 2-adrenoceptors. We tested these possibilities by pump-perfusing innervated hindlimbs in eight dogs with autologous blood kept normoxic by a membrane oxygenator while ventilating the animals for 40 min with 9% O2 in N2 (NOB group). Similar periods of normoxic ventilation preceded and followed the hypoxic period. A second group (n = 8, beta B) was pretreated with the specific beta 2 blocker ICI 118,551. Hindlimb O2 uptake was elevated by 25 min of hypoxia in NOB, whereas whole-body O2 uptake was reduced. Limb O2 uptake remained elevated in recovery, but all effects on limb O2 uptake were absent in beta B. Hindlimb resistance and perfusion pressure increased in hypoxia in both groups, and there was little evidence of local escape from reflex vasoconstriction. These results clearly indicated that global hypoxia increased O2 demand in muscle when the local O2 supply was not limited and that beta 2-receptors were necessary for this response. Autoregulatory escape of limb muscle blood flow from centrally mediated vasoconstriction during whole-body hypoxia was also shown to be practically nil, if normoxia was maintained in the limb.

Whole body and hindlimb cardiovascular responses of the anesthetized dog during CO hypoxia

1984 ◽  
Vol 62 (7) ◽  
pp. 769-774 ◽  
Author(s):  
C. E. King ◽  
S. M. Cain ◽  
C. K. Chapler
Keyword(s):  
Carbon Monoxide ◽  
Blood Flow ◽  
Cardiac Output ◽  
Sympathetic Innervation ◽  
Cardiovascular Responses ◽  
The Body ◽  
Whole Body ◽  
Total Resistance ◽  
Intact Group ◽  
Anesthetized Dogs

To compare with earlier studies of anemic hypoxia obtained by hemodilution, O2 carring capacity was decreased by carbon monoxide (CO) hypoxia. Arterial O2 content was reduced either 50% (moderate CO) or 65% (severe CO). In two groups of anesthetized dogs (moderate and severe CO) hindlimb innervation remained intact while in a third group (moderate CO) the hindlimb was denervated. Measurements were obtained prior to and at 30 and 60 min of CO hypoxia. Cardiac output was elevated at 30 min of CO hypoxia in all groups (p < 0.01) and in the severe CO group at 60 min (p < 0.01). Hindlimb blood flow remained unchanged during CO hypoxia in the intact groups. In the denervated group, hindlimb blood flow was greater (p < 0.05) than that in the intact groups throughout the experiment. A decrease in mean arterial pressure (p < 0.01) in all groups was associated with a fall in total resistance (p < 0.01). Hindlimb resistance remained unchanged during moderate CO hypoxia in the intact group but increased (p < 0.05) in the denervated group. In the severe CO group hindlimb resistance was decreased (p < 0.05) at 60 min. The results indicate that the increase in cardiac output during CO hypoxia was directed to nonmuscle areas of the body and that intact sympathetic innervation was required to achieve this redistribution.

The role of α-adrenergic receptors in carbon monoxide hypoxia

1986 ◽  
Vol 64 (11) ◽  
pp. 1442-1446 ◽  
Author(s):  
S. M. Villeneuve ◽  
C. K. Chapler ◽  
C. E. King ◽  
S. M. Cain
Keyword(s):  
Carbon Monoxide ◽  
Blood Flow ◽  
Cardiac Output ◽  
Adrenergic Receptors ◽  
Muscle Blood Flow ◽  
Control Period ◽  
Arterial Oxygen ◽  
Adrenergic Blockade ◽  
Limb Blood Flow ◽  
Arterial Oxygen Content

The importance of α-adrenergic receptors in the cardiac output and peripheral circulatory responses to carbon monoxide (CO) hypoxia was studied in anesthetized dogs. Phenoxybenzamine (3 mg/kg i.v.) was injected to block α-receptor activity and the data obtained were then compared with those from a previous study of CO hypoxia in unblocked animals. Values for cardiac output, hindlimb blood flow, vascular resistance, and oxygen uptake were obtained prior to and at 30 and 60 min of CO hypoxia which reduced arterial oxygen content by approximately 50%. α-Adrenergic blockade resulted in a lower (p < 0.05) control value for cardiac output than observed in unblocked animals, but no differences were present between the two groups at 30 or 60 min of CO hypoxia. Similarly, limb blood flow was lower (p < 0.05) during the control period in the α-blocked group but rose to the same level as that in the unblocked animals at 60 min of COH. No change in limb blood flow occurred during CO hypoxia in the unblocked group. These findings demonstrated that during CO hypoxia (i) α-receptor mediated venoconstriction does not contribute to the cardiac output response and (ii) α-receptor mediated vasoconstriction probably does prevent a rise in hindlimb skeletal muscle blood flow.

scholarly journals Resistance training increases basal limb blood flow and vascular conductance in aging humans

2006 ◽  
Vol 101 (5) ◽  
pp. 1351-1355 ◽  
Author(s):  
Maria M. Anton ◽  
Miriam Y. Cortez-Cooper ◽  
Allison E. DeVan ◽  
Daria B. Neidre ◽  
Jill N. Cook ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Strength Training ◽  
Whole Body ◽  
Control Group ◽  
Limb Blood Flow ◽  
Vascular Conductance ◽  
Femoral Blood Flow ◽  
Femoral Blood

Age-related reductions in basal limb blood flow and vascular conductance are associated with the metabolic syndrome, functional impairments, and osteoporosis. We tested the hypothesis that a strength training program would increase basal femoral blood flow in aging adults. Twenty-six sedentary but healthy middle-aged and older subjects were randomly assigned to either a whole body strength training intervention group (52 ± 2 yr, 3 men, 10 women) who underwent three supervised resistance training sessions per week for 13 wk or a control group (53 ± 2 yr, 4 men, 9 women) who participated in a supervised stretching program. At baseline, there were no significant differences in blood pressure, cardiac output, basal femoral blood flow (via Doppler ultrasound), vascular conductance, and vascular resistance between the two groups. The strength training group increased maximal strength in all the major muscle groups tested ( P < 0.05). Whole body lean body mass increased ( P < 0.05) with strength training, but leg fat-free mass did not. Basal femoral blood flow and vascular conductance increased by 55–60% after strength training (both P < 0.05). No such changes were observed in the control group. In both groups, there were no significant changes in brachial blood pressure, plasma endothelin-1 and angiotensin II concentrations, femoral artery wall thickness, cardiac output, and systemic vascular resistance. Our results indicate that short-term strength training increases basal femoral blood flow and vascular conductance in healthy middle-aged and older adults.

O2 extraction maintains O2 uptake during submaximal exercise with β-adrenergic blockade at 4,300 m

1998 ◽  
Vol 85 (3) ◽  
pp. 1092-1102 ◽  
Author(s):  
Eugene E. Wolfel ◽  
Mark A. Selland ◽  
A. Cymerman ◽  
George A. Brooks ◽  
Gail E. Butterfield ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
High Altitude ◽  
Sea Level ◽  
Submaximal Exercise ◽  
Whole Body ◽  
Exercise Heart Rate ◽  
Adrenergic Blockade ◽  
Mixed Venous

Whole body O2 uptake (V˙o 2) during maximal and submaximal exercise has been shown to be preserved in the setting of β-adrenergic blockade at high altitude, despite marked reductions in heart rate during exercise. An increase in stroke volume at high altitude has been suggested as the mechanism that preserves systemic O2 delivery (blood flow × arterial O2 content) and thereby maintainsV˙o 2 at sea-level values. To test this hypothesis, we studied the effects of nonselective β-adrenergic blockade on submaximal exercise performance in 11 normal men (26 ± 1 yr) at sea level and on arrival and after 21 days at 4,300 m. Six subjects received propranolol (240 mg/day), and five subjects received placebo. At sea level, during submaximal exercise, cardiac output and O2 delivery were significantly lower in propranolol- than in placebo-treated subjects. Increases in stroke volume and O2 extraction were responsible for the maintenance of V˙o 2. At 4,300 m, β-adrenergic blockade had no significant effect onV˙o 2, ventilation, alveolar Po 2, and arterial blood gases during submaximal exercise. Despite increases in stroke volume, cardiac output and thereby O2 delivery were still reduced in propranolol-treated subjects compared with subjects treated with placebo. Further reductions in already low levels of mixed venous O2 saturation were responsible for the maintenance ofV˙o 2 on arrival and after 21 days at 4,300 m in propranolol-treated subjects. Despite similar workloads and V˙o 2, propranolol-treated subjects exercised at greater perceived intensity than subjects given placebo at 4,300 m. The values for mixed venous O2 saturation during submaximal exercise in propranolol-treated subjects at 4,300 m approached those reported at simulated altitudes >8,000 m. Thus β-adrenergic blockade at 4,300 m results in significant reduction in O2delivery during submaximal exercise due to incomplete compensation by stroke volume for the reduction in exercise heart rate. Total bodyV˙o 2 is maintained at a constant level by an interaction between mixed venous O2 saturation, the arterial O2-carrying capacity, and hemodynamics during exercise with acute and chronic hypoxia.

Effects of alpha -adrenergic blockade during acute anemia

1982 ◽  
Vol 52 (1) ◽  
pp. 16-20 ◽  
Author(s):  
C. K. Chapler ◽  
S. M. Cain
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Volume Expansion ◽  
Cardiovascular Responses ◽  
Whole Body ◽  
Peripheral Blood Flow ◽  
Adrenergic Blockade ◽  
Acute Anemia ◽  
Alpha Blockade ◽  
Total Body Oxygen

Studies were carried out in seven anesthetized paralyzed dogs to examine the importance of alpha -adrenergic tone in the cardiovascular responses during acute anemia. Data were obtained 1) at normal hematocrit (Hct), 2) during anemia produced by isovolemic hemodilution with dextran (Hct, 13–15%), 3) during anemia after alpha -blockade (alpha -bl) with phenoxybenzamine (3 mg/kg), and 4) following volume expansion during anemia with a red blood cell dextran solution. Cardiac output (QT), limb and total body oxygen uptake (VO2), and limb blood flow (QL) were determined. Both QT and QL increased during anemia (P less than 0.01), whereas limb resistance (RL) and total peripheral resistance (TPR) were decreased (P less than 0.01). No further change in either RL or TPR occurred with alpha -blockade anemia, but both QT and QL decreased (P less than 0.01). Whole-body VO2 increased during anemia and then declined with alpha -bl and anemia. Following volume expansion during anemia with alpha -bl, QT, QL, and whole-body VO2 increased. We conclude that alpha -adrenergic sympathetic tone to capacitance vessels is essential for the cardiac output increased during anemia, but has little or no effect on resistance vessels and hence distribution of peripheral blood flow.

The role of aortic chemoreceptors during severe CO hypoxia

1985 ◽  
Vol 63 (5) ◽  
pp. 509-514 ◽  
Author(s):  
C. E. King ◽  
S. M. Cain ◽  
C. K. Chapler
Keyword(s):  
Carbon Monoxide ◽  
Blood Flow ◽  
Cardiac Output ◽  
Whole Body ◽  
Limb Blood Flow ◽  
Intact Group ◽  
Anesthetized Dogs ◽  
Dialysis Method

The importance of aortic chemoreceptors in the circulatory responses to severe carbon monoxide (CO) hypoxia was studied in anesthetized dogs. The aortic chemoreceptors were surgically denervated in eight dogs prior to the induction of CO hypoxia, with nine other dogs serving as intact controls. Values for both whole body and hindlimb blood flow, vascular resistance, and O2 uptake were determined prior to and at 30 min of CO hypoxia in the two groups. Arterial O2 content was reduced 65% using an in situ dialysis method to produce CO hypoxia. At 30 min of hypoxia, cardiac output increased but limb blood flow remained at prehypoxic levels in both groups. This indicated that aortic chemoreceptor input was not necessary for the increase in cardiac output during severe CO hypoxia, nor for the diversion of this increased flow to nonmuscle tissues. Limb O2 uptake decreased during CO hypoxia in the aortic-denervated group but remained at prehypoxic levels in the intact group. The lower resting values for limb blood flow in the aortic-denervated animals required a greater level of O2 extraction to maintain resting O2 uptake. When CO hypoxia was superimposed upon this compensation, an O2 supply limitation occurred because the limb failed to vasodilate even as maximal levels for O2 extraction were approached.

Studies of Calcium Absorption in Man Using a CD-2 Whole-Body Counter

1977 ◽  
Vol 16 (04) ◽  
pp. 163-167
Author(s):  
K. Bakos ◽  
Věra Wernischová
Keyword(s):  
Calcium Absorption ◽  
Whole Body ◽  
Control Group ◽  
Absorption Process ◽  
Whole Body Counter ◽  
Absorption Studies ◽  
Body Counting ◽  
Calcium Load ◽  
Calcium Malabsorption ◽  
Whole Body Counting

SummaryWhole-body counting makes an important contribution of radioisotope techniques to ȁEin vivo“ absorption studies, in comparison with other methods. In a large number of subjects, the method was tested for its usefulness in the diagnosis of calcium malabsorption. The effects of drugs, of the calcium load in the gut and of the whole-body content of calcium on the absorption process were studied in a control group.

scholarly journals A Comparison of the Effect of Two Types of Whole Body Vibration Platforms on Fibromyalgia. A Randomized Controlled Trial

2021 ◽  
Vol 18 (6) ◽  
pp. 3007
Author(s):  
José Antonio Mingorance ◽  
Pedro Montoya ◽  
José García Vivas Miranda ◽  
Inmaculada Riquelme
Keyword(s):  
Quality Of Life ◽  
Motor Function ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Control Group ◽  
Body Vibration ◽  
Positive Effects ◽  
Therapy Program

Whole body vibration has been proven to improve the health status of patients with fibromyalgia, providing an activation of the neuromuscular spindles, which are responsible for muscle contraction. The present study aimed to compare the effectiveness of two types of whole body vibrating platforms (vertical and rotational) during a 12-week training program. Sixty fibromyalgia patients (90% were women) were randomly assigned to one of the following groups: group A (n = 20), who performed the vibration training with a vertical platform; group B (n = 20), who did rotational platform training; or a control group C (n = 20), who did not do any training. Sensitivity measures (pressure pain and vibration thresholds), quality of life (Quality of Life Index), motor function tasks (Berg Scale, six-minute walking test, isometric back muscle strength), and static and dynamic balance (Romberg test and gait analysis) were assessed before, immediately after, and three months after the therapy program. Although both types of vibration appeared to have beneficial effects with respect to the control group, the training was more effective with the rotational than with vertical platform in some parameters, such as vibration thresholds (p < 0.001), motor function tasks (p < 0.001), mediolateral sway (p < 0.001), and gait speed (p < 0.05). Nevertheless, improvements disappeared in the follow-up in both types of vibration. Our study points out greater benefits with the use of rotational rather than vertical whole body vibration. The use of the rotational modality is recommended in the standard therapy program for patients with fibromyalgia. Due to the fact that the positive effects of both types of vibration disappeared during the follow-up, continuous or intermittent use is recommended.

scholarly journals Effect of Whole-Body Cryotherapy on Morphological, Rheological and Biochemical Indices of Blood in People with Multiple Sclerosis

2021 ◽  
Vol 10 (13) ◽  
pp. 2833
Author(s):  
Bartłomiej Ptaszek ◽  
Aneta Teległów ◽  
Justyna Adamiak ◽  
Jacek Głodzik ◽  
Szymon Podsiadło ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Neurological Diseases ◽  
Venous Blood ◽  
Whole Body ◽  
Controlled Study ◽  
Control Group ◽  
Blood Indices ◽  
Rheological Indices ◽  
Whole Body Cryotherapy ◽  
The Impact

The aim of this study was to examine and assess the impact of a series of 20 whole-body cryotherapy (WBC) treatments on the biochemical and rheological indices of blood in people with multiple sclerosis. In this prospective controlled study, the experimental group consisted of 15 women aged 34–55 (mean age, 41.53 ± 6.98 years) with diagnosed multiple sclerosis who underwent a series of whole-body cryotherapy treatments. The first control group consisted of 20 women with diagnosed multiple sclerosis. This group had no intervention in the form of whole-body cryotherapy. The second control group consisted of 15 women aged 30–49 years (mean age, 38.47 ± 6.0 years) without neurological diseases and other chronic diseases who also underwent the whole-body cryotherapy treatment. For the analysis of the blood indices, venous blood was taken twice (first, on the day of initiation of whole-body cryotherapy treatments and, second, after a series of 20 cryotherapy treatments). The blood counts were determined using an ABX MICROS 60 hematological analyzer (USA). The LORCA analyzer (Laser–Optical Rotational Cell Analyzer, RR Mechatronics, the Netherlands) was used to study the aggregation and deformability of erythrocytes. The total protein serum measurement was performed using a Cobas 6000 analyzer, Roche and a Proteinogram-Minicap Sebia analyzer. Fibrinogen determinations were made using a Bio-Ksel, Chrom-7 camera. Statistically significant differences and changes after WBC in the levels of red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), elongation index, total extend of aggregation (AMP), and proteins (including fibrinogen) were observed. However, there was no significant effect of a series of 20 WBC treatments on changes in blood counts, rheology, and biochemistry in women with multiple sclerosis. Our results show that the use of WBC has a positive effect on the rheological properties of the blood of healthy women.

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