Ventilation of lungs in deeply hypothermic rats

1961 ◽  
Vol 16 (5) ◽  
pp. 819-826 ◽  
Author(s):  
E. F. Adolph ◽  
A. Naberschnig ◽  
D. P. Orchard
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Oxygen Content ◽  
Pressure Transducer ◽  
Carotid Bodies ◽  
Linear Slope ◽  
Body Plethysmograph

Ventilation (Vi), oxygen consumption (Vo2) and heart rate (H) were measured at esophageal temperatures (T) of 8—24 C. The trachea was cannulated; a body plethysmograph and pressure transducer registered breath volumes. Vo2 was computed from oxygen content of effluent air. Vi, Vo2, and H were each related to T by a regression of low slope from 8 to 18 C, and a high nearly-linear slope above 18∘ But the proportions among the three parameters changed; Vi was relatively less below 18∘. Breaths were increasingly irregular as T decreased below 24∘. Hypoxia induced greater Vi at 16—21∘, but not at 13∘, nor after excision of the carotid bodies. Vo2 in hypoxia was greatly reduced; at 12—17∘ a Vo2 as low as one-fifth of that in air continued for an hour. H also decreased sharply at Po2 below 50 mm Hg. Carbon dioxide induced faster Vi even at 12∘; its effects were not modified by carotidectomy. Gasps were regularly induced by hypoxia, and usually by hypercapnia; they occurred just as frequently after carotidectomy. Submitted on October 26, 1960

Cardiovascular changes in the exercising emu

1983 ◽  
Vol 104 (1) ◽  
pp. 193-201 ◽  
Author(s):  
B. Grubb ◽  
D. D. Jorgensen ◽  
M. Conner
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Stroke Volume ◽  
Oxygen Content ◽  
Body Mass ◽  
Fold Increase ◽  
Exercise Heart Rate ◽  
Rate Of Oxygen Consumption ◽  
Cardiovascular Variables

Cardiovascular variables were studied as a function of oxygen consumption in the emu, a large, flightless ratite bird well suited to treadmill exercise. At the highest level of exercise, the birds' rate of oxygen consumption (VO2) was approximately 11.4 times the resting level (4.2 ml kg-1 min-1). Cardiac output was linearly related to VO2, increasing 9.5 ml for each 1 ml increase in oxygen consumption. The increase in cardiac output is similar to that in other birds, but appears to be larger than in mammals. The venous oxygen content dropped during exercise, thus increasing the arteriovenous oxygen content difference. At the highest levels of exercise, heart rate showed a 3.9-fold increase over the resting rate (45.8 beats min-1). The mean resting specific stroke volume was 1.5 ml per kg body mass, which is larger than shown by most mammals. However, birds have larger hearts relative to body mass than do mammals, and stroke volume expressed per gram of heart (0.18 ml g-1) is similar to that for mammals. Stroke volume showed a 1.8-fold increase as a result of exercise in the emus, but a change in heart rate plays a greater role in increasing cardiac output during exercise.

Relation of coronary flow to oxygen supply

1960 ◽  
Vol 199 (1) ◽  
pp. 179-182 ◽  
Author(s):  
Abraham Guz ◽  
George S. Kurland ◽  
A. Stone Freedberg
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Oxygen Content ◽  
Coronary Flow ◽  
Constant Pressure ◽  
Rabbit Heart ◽  
Hemoglobin Solution ◽  
Oxygen Capacity ◽  
Locke Solution ◽  
Solution Change

Coronary flow, heart rate, myocardial oxygen consumption and Walton strain gauge tension were determined in the isolated rabbit heart perfused with hemoglobin solutions of varying oxygen content. Perfusion was carried out under constant pressure and with the hemoglobin solution in equilibrium with 3% CO2 and 97% air under atmospheric tension. Oxygen content was varied from 2 to 18 vol. % by diluting hemoglobin with Ringer-Locke solution. Change from a higher to lower oxyhemoglobin concentration resulted in increased coronary flow; the reserve led to decreased flow. Heart rate, myocardial tension and oxygen consumption were constant at oxygen capacity above 2 vol. %.

Combined heart rate and activity improve estimates of oxygen consumption and carbon dioxide production rates

1996 ◽  
Vol 81 (4) ◽  
pp. 1754-1761 ◽  
Author(s):  
Jon K. Moon ◽  
Nancy F. Butte
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Carbon Dioxide Production ◽  
Alternative Methods ◽  
Prediction Errors ◽  
Nonlinear Functions ◽  
Production Rates ◽  
Basal Energy Expenditure

Moon, Jon K., and Nancy F. Butte. Combined heart rate and activity improve estimates of oxygen consumption and carbon dioxide production rates. J. Appl. Physiol.81(4): 1754–1761, 1996.—Oxygen consumption (V˙o 2) and carbon dioxide production (V˙co 2) rates were measured by electronically recording heart rate (HR) and physical activity (PA). Mean daily V˙o 2 andV˙co 2 measurements by HR and PA were validated in adults ( n = 10 women and 10 men) with room calorimeters. Thirteen linear and nonlinear functions of HR alone and HR combined with PA were tested as models of 24-h V˙o 2 andV˙co 2. Mean sleepV˙o 2 andV˙co 2 were similar to basal metabolic rates and were accurately estimated from HR alone [respective mean errors were −0.2 ± 0.8 (SD) and −0.4 ± 0.6%]. The range of prediction errors for 24-h V˙o 2 andV˙co 2 was smallest for a model that used PA to assign HR for each minute to separate active and inactive curves (V˙o 2, −3.3 ± 3.5%; V˙co 2, −4.6 ± 3%). There were no significant correlations betweenV˙o 2 orV˙co 2 errors and subject age, weight, fat mass, ratio of daily to basal energy expenditure rate, or fitness. V˙o 2,V˙co 2, and energy expenditure recorded for 3 free-living days were 5.6 ± 0.9 ml ⋅ min−1 ⋅ kg−1, 4.7 ± 0.8 ml ⋅ min−1 ⋅ kg−1, and 7.8 ± 1.6 kJ/min, respectively. Combined HR and PA measured 24-h V˙o 2 andV˙co 2 with a precision similar to alternative methods.

scholarly journals PO-136 Cycling Incremental test using Breath-by-breath Metabolic Cart to Predict VO2 max

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Fei Wang ◽  
Haixia Fu
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Functional Data ◽  
Maximum Oxygen Consumption ◽  
Maximum Heart Rate ◽  
Vo2 Max ◽  
Incremental Test ◽  
Metabolic Cart

Objective Maximal oxygen uptake (VO2 max) is a key indicator to assess health as well as sports performance. In heterogeneous, athletic populations, VO2 max is one of the most frequently measured variables in exercise physiology laboratories. The purpose of this study was to investigate the relationship between Maximal oxygen uptake with other metabolism parameters during one high-intensity activity, and provide simple solution for VO2 max prediction. Methods A total of 27 young athletes were selected. The incremental test was performed on a cycle ergometer (Monark 874 E, Sweden). Participants warmed up for 5 min at 50 watts (W); thereafter, the power output was increased 125 W every 3 min until exhaustion, which was defined as the incapacity to maintain a pedal cadence above 60 revolution per minute (rpm). Oxygen uptake (V̇O2), carbon dioxide production (V̇CO2) and other metabolism indexes were obtained breath-by-breath throughout the test using a metabolic cart (Quark b2, COSMED, Italy). Heart rate (HR) was measured throughout the test using a HR monitor (Polar Vantage NV, Finland). The main method in the VO2 prediction is the use of a mixed effects regression model. The potential explanatory variables include VO2kg (functional data with information on oxygen consumption per kg weight during the test), HR (functional data with heart rate information during the test), MHR (maximum heart rate of the athlete), VO2kgmean (average oxygen consumption during the test), VO2kgmax (maximum oxygen consumption value during the test), VCO2 (carbon dioxide emissions per minute during the test), HRmean (heart rate average), HRmax (maximum heart rate value during the test), age, height, weight. The model statistical analyses were implemented in R platform (version 3.3.3). Results (1) regression model results revealed MHR did not have stronger effects on VO2 max prediction. (2) Parameters of VO2kg, HR, HRmean, height, weight showed relative higher r2 values and lower RMSE values indicating the possible indexes for VO2 max prediction. (3) the interaction effects occurred between indicators which increase the complexity of the model. Conclusions In this study, a simple methodology for the prediction of maximum oxygen consumption has been presented. It combines a relatively simple level of base metabolism parameters. Despite the easy test and low level of exercise required the test provides an rational prediction of VO2 max, which could provide necessary information when it applied as a simple way. 

Ventilation of lungs in infant and adult rats and its responses to hypoxia

1960 ◽  
Vol 15 (6) ◽  
pp. 1075-1086 ◽  
Author(s):  
E. F. Adolph ◽  
P. A. Hoy
Keyword(s):  
Oxygen Consumption ◽  
Pressure Transducer ◽  
Pulmonary Ventilation ◽  
Severe Hypoxia ◽  
Low Oxygen ◽  
Adult Rats ◽  
Controlled Ventilation ◽  
Low Pressures ◽  
Body Plethysmograph

Do the controls of breathing differ with age? Pulmonary ventilation was measured by body plethysmograph and pressure transducer. After birth, breathing was irregular (pneumotaxic); steadiness from breath to breath was gained at 3 days; extraction of oxygen from the inspired air became more uniform after 10 days. In pO2 20–40 mm Hg only infants survived a half hour; ventilation did not usually increase, and often decreased. Hyperventilation even in 40 mm Hg was not sustained for many minutes in the newborn, but by 6 days was large and enduring. Heartbeats decreased in frequency during severe hypoxia. Oxygen consumption decreased 75% during hypoxia that allowed survival of infants; it sometimes recovered only slowly after hypoxia ended. Tolerance of infants to low oxygen thus consisted in ability to utilize some oxygen at low pressures and to dispense with some oxygen. Some factor other than pCO2 or pO2, possibly centrogenic, often controlled ventilation in infancy. Low oxygen maximally accelerated the breathing at an age when endurance of hypoxia remained. Submitted on May 12, 1960

scholarly journals THE OXYGEN AND CARBON DIOXIDE CONTENT OF ARTERIAL AND OF VENOUS BLOOD IN NORMAL INDIVIDUALS AND IN PATIENTS WITH ANEMIA AND HEART DISEASE

1919 ◽  
Vol 30 (3) ◽  
pp. 241-257 ◽  
Author(s):  
George A. Harrop
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Oxygen Content ◽  
Normal Values ◽  
Normal Individual ◽  
Venous Blood ◽  
Carbon Dioxide Content ◽  
Arterial Blood ◽  
Percentage Saturation ◽  
Normal Individuals

1. The oxygen content of venous and of arterial blood from fifteen essentially normal individuals at rest in bed has been determined. 2. The percentage saturation of the arterial blood has varied between 100 and 94.3. The average is 95.5 per cent. 3. The oxygen consumption has varied between 2.6 and 8.3 volumes per cent. 4. The oxygen content and the percentage saturation of arterial blood taken at close intervals from three different peripheral arteries of a normal individual have shown values agreeing within the limits of error. Analyses of the blood gases of a normal individual, at rest and after exercise, have shown a lowering of the percentage oxygen saturation of the arterial blood and a diminished carbon dioxide content after exercise. 5. In three persons with severe anemia the saturation of the arterial blood has not differed from the normal. Very low absolute values were found for the oxygen content of the venous blood, but the normal oxygen consumption has been maintained. 6. The carbon dioxide content of the arterial blood from ten normal individuals has varied between 54.7 and 44.6 volumes per cent. That of the venous blood has varied between 60.4 and 48.3 volumes per cent. 7. No deviations from the normal values for oxygen and carbon dioxide were found in venous and arterial blood from cardiac patients without arrhytiunias, well compensated, and at rest in bed. 8. A series of determinations has been made upon nine cardiac patients with varying degrees of decompensation. The percentage oxygen saturation of the arterial blood on admission was abnormally low in seven of these cases. With the return to compensation and with the clearing up of pulmonary symptoms, the percentage saturation of the arterial blood returned to normal in four of them. 9. In a case of long standing mitral endocarditis with auricular fibrillation it remained low over a period of I month of observation. 10. In a case of chronic myocarditis secondary to emphysema and chronic bronchitis, it remained low over the period of observation. 11. Normal values for the percentage saturation of the arterial blood were found in two individuals with decompensated aortic disease but without physical signs of extensive pulmonary involvement. 12. The oxygen consumption tended to be high in individuals with cardiac disease during the periods of marked decompensation and to be lower as compensation was regained. 13. The data presented indicate that at least in many circulatory diseases during decompensation, particularly when there are physical signs of pulmonary congestion, there is a disturbance of the pulmonary exchange, as indicated by the lowering of the percentage saturation of the arterial blood with oxygen.

Microbial efficiency in a meromictic reservoir

2008 ◽  
Vol 37 (2) ◽  
Author(s):  
Grażyna Mazurkiewicz-Boroń ◽  
Teresa Bednarz ◽  
Elżbieta Wilk-Woźniak
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Release Rate ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Metabolic Efficiency ◽  
Sulphur Compounds ◽  
Carbon Dioxide Release ◽  
Microbial Efficiency ◽  
Ion Contents

Microbial efficiency in a meromictic reservoirIndices of microbial efficiency (expressed as oxygen consumption and carbon dioxide release) were determined in the water column of the meromictic Piaseczno Reservoir (in an opencast sulphur mine), which is rich in sulphur compounds. Phytoplankton abundances were low in both the mixolimnion (up to 15 m depth) and monimolimnion (below 15 m depth). In summer and winter, carbon dioxide release was 3-fold and 5-fold higher, respectively, in the monimolimnion than in the mixolimnion. Laboratory enrichments of the sulphur substrate of the water resulted in a decrease in oxygen consumption rate of by about 42% in mixolimnion samples, and in the carbon dioxide release rate by about 69% in monimolimnion samples. Water temperature, pH and bivalent ion contents were of major importance in shaping the microbial metabolic efficiency in the mixolimnion, whilst in the monimolimnion these relationships were not evident.

CARDIORESPIRATORY SYSTEM UNDER BICYCLE ERGOMETER TEST IN SKIERS WITH DIFFERENT TRAINING STATUS (KOMI REPUBLIC)

2019 ◽  
pp. 76-84
Author(s):  
Yu.G. Solonin ◽  
T.P. Loginova ◽  
I.O. Garnov ◽  
A.L. Markov ◽  
A.A. Chernykh ◽  
...  
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Komi Republic ◽  
Rate Pressure Product ◽  
Training Status ◽  
Maximum Oxygen Consumption ◽  
Bicycle Ergometry ◽  
Cardiorespiratory System ◽  
Unit Pulse ◽  
Ski Racers

The aim of the study is to examine the impact of training status on ski racers (Komi Republic) at rest and under bicycle ergometry evaluating their cardiorespiratory system parameters. Materials and Methods. The authors examined male ski racers with different training status: 22 first-rank sportsmen, 22 candidates for Master of Sports and 22 Masters of Sports. Athletes underwent bicycle ergometry loads up to refusal. Oxycon Pro system (Germany) was used. Then authors studied the complex of cardiorespiratory parameters, calculating maximum oxygen consumption and unit physiological cost. Results. At rest and under standard physical load (200 W) Masters of Sports demonstrate significantly increased training status among ski racers in such cardiorespiratory system parameters as heart rate, rate pressure product and oxygen pulse. Under standard physical load (200 W) statistically significant differences between first-rank sportsmen and candidates for Master of Sports are detected by heart rate, rate pressure product, respiration rate, respiratory minute volume and oxygen utilization coefficient. Such deviations indicate differences in training status. Under maximum load, the highest training status is found in Masters of Sports: bicycle ergometry load power and duration; unit pulse, pressor and cardiac cost, bulk and unit values of maximum oxygen consumption. Heart rate values, unit pulse and heart-vent cost indicate a high training status in candidates for Master of Sports under load up to refusal, if compared with first-rank sportsmen. Athletes’ organism under load up to refusal works more efficiently than under moderate load (200 W). The training status in ski racers (Komi Republic) is manifested in the saving cardiorespiratory system functions, both at rest and under standard bicycle ergometry, as well as in parameters of unit physiological cost under loads up to refusal and increased values of maximum oxygen consumption. Keywords: ski racers, Komi Republic, training status, bicycle ergometry loads, cardiorespiratory system, maximum oxygen consumption.

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