Effects of cocaine on incremental treadmill exercise in horses

1993 ◽  
Vol 75 (6) ◽  
pp. 2727-2733 ◽  
Author(s):  
K. H. McKeever ◽  
K. W. Hinchcliff ◽  
D. F. Gerken ◽  
R. A. Sams
Keyword(s):  
Right Ventricular ◽  
Blood Lactate ◽  
Venous Blood ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Ventricular Pressure ◽  
Mixed Venous Blood ◽  
Work Intensity ◽  
Venous Blood Lactate ◽  
Mixed Venous

Four mature horses were used to test the effects of two doses (50 and 200 mg) of intravenously administered cocaine on hemodynamics and selected indexes of performance [maximal heart rate (HRmax), treadmill velocity at HRmax, treadmill velocity needed to produce a blood lactate concentration of 4 mmol/l, maximal mixed venous blood lactate concentration, maximal treadmill work intensity, and test duration] measured during an incremental treadmill test. Both doses of cocaine increased HRmax approximately 7% (P < 0.05). Mean arterial pressure was 30 mmHg greater (P < 0.05) during the 4- to 7-m/s steps of the exercise test in the 200-mg trial. Neither dose of cocaine had an effect on the responses to exertion of right atrial pressure, right ventricular pressure, or maximal change in right ventricular pressure over time. Maximal mixed venous blood lactate concentration increased 41% (P < 0.05) with the 50-mg dose and 75% (P < 0.05) with the 200-mg dose during exercise. Administration of cocaine resulted in decreases (P < 0.05) in the treadmill velocity needed to produce a blood lactate concentration of 4 mmol/l from 6.9 +/- 0.5 and 6.8 +/- 0.9 m/s during the control trials to 4.4 +/- 0.1 m/s during the 200-mg cocaine trial. Cocaine did not alter maximal treadmill work intensity (P > 0.05); however, time to exhaustion increased by approximately 92 s (15%; P < 0.05) during the 200-mg trial.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Arterialized and venous blood lactate concentration difference during different exercise intensities

2017 ◽  
Vol 15 (1) ◽  
pp. 22-26 ◽  
Author(s):  
Leandro C. Felippe ◽  
Guilherme A. Ferreira ◽  
Fernando De-Oliveira ◽  
Flavio O. Pires ◽  
Adriano E. Lima-Silva
Keyword(s):  
Blood Lactate ◽  
Venous Blood ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Concentration Difference ◽  
Venous Blood Lactate

Fingertip and venous blood lactate concentration in response to graded treadmill exercise

1993 ◽  
Vol 11 (2) ◽  
pp. 139-143 ◽  
Author(s):  
M.S. El‐Sayed ◽  
K.P. George ◽  
D. Wilkinson ◽  
N. Mullan ◽  
R. Fenoglio ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Treadmill Exercise ◽  
Venous Blood ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Venous Blood Lactate

Pulmonary vasoconstrictor response to acute decrease in blood P50

1984 ◽  
Vol 56 (2) ◽  
pp. 370-374 ◽  
Author(s):  
B. P. Teisseire ◽  
C. D. Soulard
Keyword(s):  
Right Ventricular ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Venous Blood ◽  
Systolic Pressure ◽  
Mixed Venous Blood ◽  
Right Ventricular Systolic Pressure ◽  
Ventricular Systolic Pressure ◽  
Arterial Blood ◽  
Alveolar Hypoxia ◽  
Mixed Venous

The O2 sensor that triggers hypoxic pulmonary vasoconstriction may be sensitive not only to alveolar hypoxia but also to hypoxia in mixed venous blood. A specific test of the blood contribution would be to lower mixed venous PO2 (PvO2), which can be accomplished by increasing hemoglobin-O2 affinity. When we exchanged transfused rats with cyanate-treated erythrocytes [PO2 at 50% hemoglobin saturation (P50) = 21 Torr] or with Creteil erythrocytes (P50 = 13.1 Torr), we lowered PvO2 from 39 +/- 5 to 25 +/- 4 and to 14 +/- 4 Torr, respectively, without altering arterial blood gases or hemoglobin concentration. Right ventricular systolic pressure increased from 32 +/- 2 to 36 +/- 3 Torr with cyanate erythrocytes and to 44 +/- 5 Torr with Creteil erythrocytes. Cardiac output was unchanged. Control exchange transfusions with normal rat or 2,3-diphosphoglycerate-enriched human erythrocytes had no effect on PvO2 or right ventricular pressure. Alveolar hypoxia plus high O2 affinity blood caused a greater increase in right ventricular systolic pressure than either stimulus alone. We concluded that PvO2 is an important determinant of pulmonary vascular tone in the rat.

Increase in Serum Ionized Calcium during Exercise

1977 ◽  
Vol 53 (6) ◽  
pp. 579-586 ◽  
Author(s):  
S. Pors Nielsen ◽  
T. Falch Christiansen ◽  
O. Hartling ◽  
J. Trap-Jensen
Keyword(s):  
Blood Lactate ◽  
Venous Blood ◽  
Recovery Period ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Normal Subjects ◽  
Ionized Calcium ◽  
Serum Ionized Calcium

1. Normal subjects showed an average increase in serum ionized calcium (Ca2+) concentration of 0·11 mmol/l in peripheral venous blood 10 min after onset of bicycle exercise at 70% of maximum aerobic capacity. The corresponding mean rise in serum total calcium concentration was 0·21 mmol/l. 2. The change in serum Ca2+ as result of acidification was studied in 20 normal subjects by carbon dioxide equilibration in vitro followed by measurement of serum Ca2+. The log serum Ca2+ was inversely proportional to serum pH. 3. The Δlog serum Ca2+/ΔpH in vitro was similar to the Δlog serum Caa+/ΔpH in vivo during exercise, this ratio, however, being somewhat greater during the first minute of exercise. 4. Serum Ca2+ returned to normal values about 20 min after stopping exercise as the pH returned to normal, but the fall immediately after stopping exercise was more pronounced than that due to the change in pH, as predicted from the studies in vitro. 5. Blood lactate concentration rose from 0·86 to 8·41 mmol/l after 10 min exercise, but the rise in blood lactate during exercise was slower than the rise in serum Ca2+. Also the fall during the recovery period was delayed compared with the fall in serum Ca2+. 6. It is suggested that the rise in serum Ca2+ during severe muscular exercise might be important for the physiological adaptations during work, and for bone metabolism.

scholarly journals Lactate Arterial-Central Venous Gradient among COVID-19 Patients in ICU: A Potential Tool in the Clinical Practice

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Giuseppe Nardi ◽  
Gianfranco Sanson ◽  
Lucia Tassinari ◽  
Giovanna Guiotto ◽  
Antonella Potalivo ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Venous Blood ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Mitochondrial Metabolism ◽  
Lung Cells ◽  
Central Venous ◽  
Central Venous Blood ◽  
Arterial Blood ◽  
Anti Inflammatory

Objective. In physiological conditions, arterial blood lactate concentration is equal to or lower than central venous blood lactate concentration. A reversal in this rate (i.e., higher lactate concentration in central venous blood), which could reflect a derangement in the mitochondrial metabolism of lung cells induced by inflammation, has been previously reported in patients with ARDS but has been never explored in COVID-19 patients. The aim of this study was to explore if the COVID-19-induced lung cell damage was mirrored by an arterial lactatemia higher than the central venous one; then if the administration of anti-inflammatory therapy (i.e., canakinumab 300 mg subcutaneous) could normalize such abnormal lactate a-cv difference. Methods. A prospective cohort study was conducted, started on March 25, 2020, for a duration of 10 days, enrolling 21 patients affected by severe COVID-19 pneumonia undergoing mechanical ventilation consecutively admitted to the ICU of the Rimini Hospital, Italy. Arterial and central venous blood samples were contemporarily collected to calculate the difference between arterial and central venous lactate (Delta a-cv lactate) concentrations within 24 h from tracheal intubation (T0) and 24 hours after canakinumab administration (T1). Results. At T0, 19 of 21 (90.5%) patients showed a pathologic Delta a-cv lactate (median 0.15 mmol/L; IQR 0.07–0.25). In the 13 patients undergoing canakinumab administration, at T1, Delta a-cv lactate decreased in 92.3% of cases, the decrease being statistically significant (T0: median 0.24, IQR 0.09–0.31 mmol/L; T1: median −0.01, IQR −0.08–0.04 mmol/L; p=0.002). Conclusion. A reversed Delta a-cv lactate might be interpreted as one of the effects of COVID-19-related cytokine storm, which could reflect a derangement in the mitochondrial metabolism of lung cells induced by severe inflammation or other uncoupling mediators. In addition, Delta a-cv lactate decrease might also reflect the anti-inflammatory activity of canakinumab. Our preliminary findings need to be confirmed by larger outcome studies.

A method for sampling representative muscular venous blood during exercise in rats

1993 ◽  
Vol 27 (2) ◽  
pp. 171-175 ◽  
Author(s):  
T. Pagés ◽  
J. A. Fernáandez ◽  
C. Adán ◽  
A. Gámez ◽  
G. Viscor ◽  
...  
Keyword(s):  
Femoral Vein ◽  
Venous Blood ◽  
Lactate Concentration ◽  
Mixed Venous Blood ◽  
Hindlimb Muscle ◽  
Anaesthetized Rats ◽  
Muscular Branch ◽  
Chronic Cannulation ◽  
Mixed Venous ◽  
Vascular Corrosion Casts

A technique for chronic cannulation of the muscular branch of the femoral vein in the rat is described. The method was validated by the application of vascular corrosion casts and comparative analysis of lactate concentration with mixed venous blood and arterial samples taken through the cannulas during lower hindlimb muscle contraction in anaesthetized rats.

Operation Everest II: oxygen transport during exercise at extreme simulated altitude

1988 ◽  
Vol 64 (4) ◽  
pp. 1309-1321 ◽  
Author(s):  
J. R. Sutton ◽  
J. T. Reeves ◽  
P. D. Wagner ◽  
B. M. Groves ◽  
A. Cymerman ◽  
...  
Keyword(s):  
Sea Level ◽  
Blood Lactate ◽  
Venous Blood ◽  
Blood Gases ◽  
Work Load ◽  
Open Circuit ◽  
Mixed Venous Blood ◽  
O2 Uptake ◽  
Fourfold Increase ◽  
Mixed Venous

A decrease in maximal O2 uptake has been demonstrated with increasing altitude. However, direct measurements of individual links in the O2 transport chain at extreme altitude have not been obtained previously. In this study we examined eight healthy males, aged 21-31 yr, at rest and during steady-state exercise at sea level and the following inspired O2 pressures (PIO2): 80, 63, 49, and 43 Torr, during a 40-day simulated ascent of Mt. Everest. The subjects exercised on a cycle ergometer, and heart rate was recorded by an electrocardiograph; ventilation, O2 uptake, and CO2 output were measured by open circuit. Arterial and mixed venous blood samples were collected from indwelling radial or brachial and pulmonary arterial catheters for analysis of blood gases, O2 saturation and content, and lactate. As PIO2 decreased, maximal O2 uptake decreased from 3.98 ±0.20 l/min at sea level to 1.17 ± 0.08 l/min at PIO2 43 Torr. This was associated with profound hypoxemia and hypocapnia; at 60 W of exercise at PIO2 43 Torr, arterial PO2 = 28 ± 1 Torr and PCO2 = 11 ± 1 Torr, with a marked reduction in mixed venous PO2 [14.8 ± 1 (SE) Torr]. Considering the major factors responsible for transfer of O2 from the atmosphere to the tissues, the most important adaptations occurred in ventilation where a fourfold increase in alveolar ventilation was observed. Diffusion from alveolus to end-capillary blood was unchanged with altitude. The mass circulatory transport of O2 to the tissue capillaries was also unaffected by altitude except at PIO2 43 Torr where cardiac output was increased for a given O2 uptake. Diffusion from the capillary to the tissue mitochondria, reflected by mixed venous PO2, was also increased with altitude. With increasing altitude, blood lactate was progressively reduced at maximal exercise, whereas at any absolute and relative submaximal work load, blood lactate was higher. These findings suggest that although glycogenolysis may be accentuated at low work loads, it may not be maximally activated at exhaustion.

scholarly journals Nasal strips do not affect pulmonary gas exchange, anaerobic metabolism, or EIPH in exercising Thoroughbreds

2001 ◽  
Vol 90 (6) ◽  
pp. 2378-2385 ◽  
Author(s):  
Thomas E. Goetz ◽  
Murli Manohar ◽  
Aslam S. Hassan ◽  
Gordon J. Baker
Keyword(s):  
Blood Lactate ◽  
Anaerobic Metabolism ◽  
Maximal Exercise ◽  
Venous Blood ◽  
Pulmonary Hemorrhage ◽  
Mixed Venous Blood ◽  
Arterial Hypoxemia ◽  
Thoroughbred Horses ◽  
Exercise Induced ◽  
Mixed Venous

The present study was carried out to examine whether nasal strip application would improve the exercise-induced arterial hypoxemia and hypercapnia, diminish anaerobic metabolism, and modify the incidence of exercise-induced pulmonary hemorrhage (EIPH) in horses. Two sets of experiments, control and nasal strip experiments, were carried out on seven healthy, sound, exercise-trained Thoroughbred horses in random order, 7 days apart. Simultaneous measurements of core temperature, arterial and mixed venous blood gases/pH, and blood lactate and ammonia concentrations were made at rest, during submaximal and near-maximal exercise, and during recovery. In both treatments, whereas submaximal exercise caused hyperventilation, near-maximal exercise induced significant arterial hypoxemia, desaturation of Hb, hypercapnia, and acidosis. However, O2 content increased significantly with exercise in both treatments, while the mixed venous blood O2 content decreased as O2 extraction increased. In both treatments, plasma ammonia and blood lactate concentrations increased significantly with exercise. Statistically significant differences between the control and the nasal strip experiments could not be discerned, however. Also, all horses experienced EIPH in both treatments. Thus our data indicated that application of an external nasal dilator strip neither improved the exercise-induced arterial hypoxemia and hypercapnia nor diminished anaerobic metabolism or the incidence of EIPH in Thoroughbred horses performing strenuous exercise.

The influence of execution speed on blood lactate concentration in strength training protocol in bench press exercise

2020 ◽  
Vol 19 (1) ◽  
pp. 32
Author(s):  
Gustavo Taques Marczynski ◽  
Luís Carlos Zattar Coelho ◽  
Leonardo Emmanuel De Medeiros Lima ◽  
Rodrigo Pereira Da Silva ◽  
Dilmar Pinto Guedes Jr ◽  
...  
Keyword(s):  
Strength Training ◽  
Blood Lactate ◽  
Bench Press ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
The Third ◽  
Fast Speed ◽  
Work Volume ◽  
Execution Speed ◽  
Training Protocol

The aim of this study was to analyze the influence of two velocities of execution relative to blood lactate concentration in strength training exercise until the momentary concentric failure. Fifteen men (29.1 ± 5.9 years), trained, participated in the experiment. The volunteers performed three bench press sessions, with an interval of 48 hours between them. At the first session, individuals determined loads through the 10-12 RMs test. In the following two sessions, three series with 90 seconds of interval were performed, in the second session slow execution speed (cadence 3030) and later in the third session fast speed (cadence 1010). For statistical analysis, the Student-T test was used for an independent sample study and considered the value of probability (p) ≤ 0.05 statistically significant. By comparing the number of repetitions and time under tension of the two runs, all series compared to the first presented significant reductions (p < 0.05). The total work volume was higher with the fast speed (p < 0.05). The study revealed that rapid velocities (cadence 1010) present a higher concentration of blood lactate when compared to slow runs (cadence 3030). The blood lactate concentration, in maximum repetitions, is affected by the speed of execution.Keywords: resistance training, cadence, blood lactate.

Sign in / Sign up

Export Citation Format

Share Document