Responses of the Respiratory Pumps to Hypoxia in the Rainbow Trout (Salmo Gairdneri)

1970 ◽  
Vol 53 (3) ◽  
pp. 529-545 ◽  
Author(s):  
G. M. HUGHES ◽  
R. L. SUNDERS
Keyword(s):  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Stroke Volume ◽  
Minute Volume ◽  
Differential Pressure ◽  
Salmo Gairdneri ◽  
Oxygen Cost ◽  
Volume Measurements ◽  
Overall Efficiency ◽  
Work Done

1. Unanaesthetized rainbow trout, when subjected to a lowered Po2 of the inspired water, show an increase in amplitude of pressures recorded from the buccal and opercular cavities. Pressure amplitudes were commonly found to be 0.5 cm of water in resting trout and increased 4- or 5-fold as inspired Po2 was reduced. Differential pressures across the gills also increased with hypoxia. 2. Typically the minute volume in a 400-600 g trout increased from about 0.2 to 0.6 l/kg/min when the inspired Po2 was lowered from 150 to 80 mm Hg, but rose to 1-5l/kg/min at lower Po2. Increased minute volumes are mainly due to increases in stroke volume; respiratory frequency remains fairly constant at Po2 's above about 8o mm Hg. 3. The relation between differential pressure and minute volume is fairly linear over much of the range, but minute volume increases more rapidly than differential pressure. 4. Oxygen consumption of the non-swimming fish increases during hypoxia and is related to the increased ventilation and differential pressure across the gills. 5. Estimates of the oxygen cost of breathing were made from the increased oxygen consumption during hyperventilation. Comparison of these estimates with estimates of the work done, using the pressure and volume measurements, gave figures for the overall efficiency of the pumping mechanism of about 10%.

Gill Irrigation and Pressure Relationships in Rainbow Trout (Salmo gairdneri)

1973 ◽  
Vol 30 (1) ◽  
pp. 99-104 ◽  
Author(s):  
John C. Davis ◽  
David J. Randall
Keyword(s):  
Rainbow Trout ◽  
Oxygen Uptake ◽  
Dead Space ◽  
Ventilation Rate ◽  
Differential Pressure ◽  
Salmo Gairdneri ◽  
Oxygen Cost ◽  
Low Area ◽  
Anatomical Dead Space ◽  
Marked Decline

In studies on 11 rainbow trout (Salmo gairdneri), 217.3 ± 6.5 g, 14.0 ± 0.5 C) fitted with rubber membranes for direct measurement of ventilatory water flow [Formula: see text], buccal, cleithral, and differential pressure traces increased in amptitude as [Formula: see text] rose from 40 to 160 ml/min. Ventilation rate remained steady at around 77 breaths/min in the [Formula: see text] range 40–120 ml/min and rose to 90 breaths/min at a [Formula: see text] of 175 ml/min. Oxygen uptake more than doubled as [Formula: see text] rose from 40 to 120 ml/min. Calculated utilization of oxygen from the inspired water declined only slightly over this [Formula: see text] range, indicating that large increases in nonrespiratory spillage of water (anatomical dead space) had not occurred. The calculated oxygen cost of breathing was low. Area mean differential pressure appeared closely related to [Formula: see text] over the [Formula: see text] range 40–160 ml/min. Area mean differential pressure increased from two- to four fold over this [Formula: see text] range, depending upon which individual fish was examined. Over the [Formula: see text] range 40–160 ml/min the calculated resistance of the gill sieve did not appear to decline although some variability was present and a variety of gill sieve resistances could be measured at a given [Formula: see text] for each fish. It is concluded that changes in [Formula: see text] are largely dependent on changes in mean differential pressures across the gills, with no marked decline in gill sieve resistance over the normal physiological range of [Formula: see text].

THE EFFECT OF TEMPERATURE AND PHOTOPERIOD ON THE RESPIRATORY METABOLISM OF RAINBOW TROUT (SALMO GAIRDNERI)

1962 ◽  
Vol 40 (1) ◽  
pp. 107-118 ◽  
Author(s):  
R. M. Evans ◽  
F. C. Purdie ◽  
C. P. Hickman Jr.
Keyword(s):  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Locomotor Activity ◽  
Temperature Compensation ◽  
Large Degree ◽  
Effect Of Temperature ◽  
Salmo Gairdneri ◽  
Respiratory Metabolism ◽  
Metabolic Rates ◽  
Metabolic Compensation

Mid-winter spawning rainbow trout (Salmo gairdneri) were acclimated for a minimum of 43 days to one of four temperature–photoperiod conditions: 16 °C–16L (hours daily photoperiod), 16 °C–8L, 8 °C–16L, 8 °C–8L. Oxygen consumption of the intact fish and of samples of liver, gill, and brain were measured at acclimation temperature.Brain showed complete metabolic compensation to temperature ([Formula: see text] at [Formula: see text] at 16 °C) and liver showed overcompensation ([Formula: see text] at [Formula: see text] at 16 °C). No compensation occurred in gill respiration. Total respiration showed partial temperature compensation. It is suggested that complete compensation in brain would maintain nervous co-ordination and motor conduction at optimal levels, thus permitting a large degree of temperature independence of locomotor activity.[Formula: see text] values of the tissue showed a trend for the 8L tissues to metabolize more rapidly than the 16L group, except for gill at 16 °C. Photoperiod did not significantly affect total metabolic rates, but in the larger fish (> 40 g) at 16 °C, the 8L group tended to show a higher metabolic rate than the 16L group.

DORSAL AORTIC BLOOD PRESSURES RECORDED FROM THE RAINBOW TROUT (SALMO GAIRDNERI)

1965 ◽  
Vol 43 (5) ◽  
pp. 863-872 ◽  
Author(s):  
D. J. Randall ◽  
L. S. Smith ◽  
J. R. Brett
Keyword(s):  
Blood Pressure ◽  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Systolic Blood Pressure ◽  
Salmo Gairdneri ◽  
Free Swimming ◽  
Aortic Blood ◽  
Cannulation Technique ◽  
Blood Pressures

Dorsal aortic blood pressures were recorded from unanesthetized, free-swimming intact fish by a previously described cannulation technique. Some cardiovascular and breathing changes during recovery from the operation and anesthesia are reported. Dorsal aortic systolic blood pressures of 38.7 ± 2.9 mm Hg were recorded from unrestrained intact trout (Salmo gairdneri). A limited study indicated that there were no variations in dorsal aortic systolic blood pressure with changes in oxygen consumption in quiescent fish.

Effects of exercise on heart output of the dog

1961 ◽  
Vol 16 (1) ◽  
pp. 107-111 ◽  
Author(s):  
Michael D. Bailie ◽  
Sid Robinson ◽  
Howard H. Rostorfer ◽  
Jerry L. Newton
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Carotid Artery ◽  
Stroke Volume ◽  
Minute Volume ◽  
Open Circuit ◽  
Work Rate ◽  
Left Carotid Artery ◽  
The Right ◽  
Oxygen Difference

Effects of varying rates of work on the heart output of healthy young dogs were determined by the direct Fick method. Blood was sampled simultaneously through a polyethylene catheter in the right ventricle and an inlying needle in the left carotid artery. Heart rates were determined from right ventricular pressure recordings. Oxygen consumption was determined by the open-circuit method. Oxygen consumption of the dog was linearly related to work rate in runs on the treadmill at 5.6, 9.6 and 12.9 km/hr. up an 18% grade. Minute volume of the heart, arteriovenous oxygen difference, heart rate and stroke volume were found to increase with increasing metabolic rate. The average stroke volume in the hardest work rate was 82% greater than the average resting value. An animal whose activity had been greatly restricted for 3 months showed a 62% increase in stroke volume from rest to running on the treadmill at 9.6 km/hr. up an 18% grade. The data show that a substantial increase in stroke volume in work must necessarily occur in order to account for the observed increase in minute volume. Submitted on May 10, 1960

scholarly journals Oxygen Consumption and Swimming Performance in Hypoxia-Acclimated Rainbow Trout Salmo Gairdneri

1984 ◽  
Vol 113 (1) ◽  
pp. 225-235 ◽  
Author(s):  
P. G. BUSHNELL ◽  
J. F. STEFFENSEN ◽  
K. JOHANSEN
Keyword(s):  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Swimming Performance ◽  
Relative Increase ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Swimming Velocity ◽  
Loading Capacity ◽  
Blood Oxygen ◽  
Normoxic Control

1. Swimming performance and oxygen consumption of normoxic (control) and hypoxia-acclimated (P002=40 mmHg) rainbow trout, Salmo gairdneri Richardson, were monitored at >145, 60 and 40mmHg. 2. Maximum swimming velocity at 40mmHg was reduced from >54.8cm s−1 to 41.4cm s1 in controls and to 40.6 cm s−1 in hypoxiaacclimated fish. 3. Normoxic oxygen consumption of control fish ranged from 97.5 mg O2 kg−1 h−1(5.5cm s−1) to 318.5 mg O2 kg−1 h−1 (54.8 cm s−1) and did not differ significantly from that of hypoxia-acclimated fish in normoxia. 4. Reduction of ambient P002 from normoxia to 60mmHg or 40mmHg did not significantly change oxygen consumption in control animals, although no fish (control or hypoxia acclimated) completed swimming trials at 54.8cm s−1 in 40mmHg. 5. Oxygen consumption of hypoxia-acclimated fish at 5.5cm s−1 and 40 mmHg was significantly higher than oxygen uptake in normoxia at the same speed. This relative increase was not maintained, however, as oxygen consumption at higher swimming speeds was similar to that in normoxia. 6. Blood studies showed that hypoxia-acclimated fish had lower ATP concentrations and P50 values. While these factors may increase the blood oxygen loading capacity, the change is apparently not enough markedly to improve swimming performance or oxygen consumption in hypoxia and/or exercise.

Water Flow and Gas Exchange at the Gills of Rainbow Trout, Salmo Gairdneri

1971 ◽  
Vol 54 (1) ◽  
pp. 1-18 ◽  
Author(s):  
JOHN C. DAVIS ◽  
JAMES N. CAMERON
Keyword(s):  
Rainbow Trout ◽  
Gas Exchange ◽  
Stroke Volume ◽  
Water Flow ◽  
Ventilation Rate ◽  
Salmo Gairdneri ◽  
Perfusion Rate ◽  
Rubber Membrane ◽  
Flow Rates ◽  
Arterial Blood

1. Ventilation volume was measured directly in rainbow trout using a rubber membrane attached to the mouth which separated inspired and expired water and allowed collection of the latter. 2. Mean ventilation volume at 8.6 °C for 18 trout weighing approximately 200 g was 37±1.8 ml/min/fish. Mean ventilation rate and ventilatory stroke volume averaged 74 breaths/min and 0.5 ml/breath respectively. 3. Ventilation volume could be increased nearly sevenfold during moderate, shortterm hypoxia as a result of a large increase in ventilatory stroke volume and a small increase in ventilation rate. 4. The ratio between the flow rates of water and blood through the gills was approximately 10. 5. Percentage utilization of oxygen from inspired water had a mean of 46±1.5% and ranged from 23 to 64%. 6. Artificial perfusion of the gills with water at different flow rates was achieved by tying a tube into the mouth of trout. 7. Perfused fish could not saturate their arterial blood with oxygen at a perfusion rate of 45 ml/min but could do so at rates ranging from 85 to 1200 ml/min. 8. Low arterial tensions at a perfusion rate approximating the mean V·G of fish with oral membranes are probably the result of a poor pattern of water flow over the gills during perfusion. 9. Opercular movements occurred only at perfusion rates below 700 ml/min and increased in frequency as perfusion rate dropped. This ventilatory activity may have resulted from receptors sensitive either to water flow over the gills or to arterial Po2. 10. As perfusion rate went up cardiac output and oxygen uptake increased. These changes were accompanied by a drop in dorsal aortic pressure which reflected vasodilation of the gills and peripheral circulation. This change in the pattern of blood flow through the gills contributed to a 50% increase in oxygen transfer factor across the gills. 11. At the highest perfusion rates there was no apparent impairment of gas exchange even though anatomical deadspace was probably high.

The effect of changes in blood oxygen-carrying capacity on ventilation volume in the rainbow trout (Salmo gairdneri)

1982 ◽  
Vol 97 (1) ◽  
pp. 325-334
Author(s):  
F. M. Smith ◽  
D. R. Jones
Keyword(s):  
Rainbow Trout ◽  
Stroke Volume ◽  
Oxygen Content ◽  
Carrying Capacity ◽  
Salmo Gairdneri ◽  
Blood Oxygen ◽  
Breathing Frequency ◽  
Ventilatory Responses ◽  
Low Levels ◽  
Oxygen Carrying Capacity

1. Changes in ventilation volume (Vg) of rainbow trout caused by hypercapnia, hypoxia and anaemia were measured directly by collection of expired water. 2. Exposure to hypercapnic water (PCO2 range 0.5-2 kPa) increased Vg (by up to four times) by augmenting ventilatory stroke volume; breathing frequency remained constant. O2 added to the inspired water in maintained hypercapnia reduced Vg at all but the highest level of PCO2. 3. Vg increased when blood oxygen content was decreased by exposure to normoxic hypercapnia, but addition of O2 to the water increased blood oxygen content and Vg decreased. 4. When blood oxygen-carrying capacity was depressed by hypoxia or anaemia, Vg increased as it did during normoxic hypercapnia. 5. We suggest that ventilatory responses to low levels of hypercapnia, to hyperoxic hypercapnia, to hypoxia, and to anaemia in trout are related to changes in levels of blood oxygen content under these conditions.

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