Exercising with and Without Lungs: II. Experimental Elimination of Pulmonary and Buccopharyngeal Gas Exchange in Individual Salamanders (Ambystoma Tigrinum)

1988 ◽  
Vol 138 (1) ◽  
pp. 487-497 ◽  
Author(s):  
MARTIN E. FEDER
Keyword(s):  
Oxygen Consumption ◽  
Gas Exchange ◽  
Ambystoma Tigrinum ◽  
Airway Closure ◽  
Diffusing Capacity ◽  
Oxygen Requirement ◽  
Aerobic Activity ◽  
Before And After ◽  
Rate Of Oxygen Consumption ◽  
Limited Scope

To ascertain whether the presence of lungs per se, or some other physiological feature, might account for the differences in oxygen consumption and stamina previously observed in an interspecific comparison (Full et al. 1988), individual salamanders (Ambystoma tigrinum) were exercised on a treadmill before and after their nares and mouth had been sealed. After airway closure, animals behaved normally and suffered no mortality. Airway closure reduced the routine MO2 (rate of oxygen consumption) by an average of 47% in six of seven individuals. Animals with open airways increased their MO2 2-to 4-fold during locomotion at 11 cm s−1, and did not fatigue in 22 min of exercise at this speed. Animals with closed airways managed only small increases above the routine MO2 during exercise at 11 cm s−1, and none could sustain activity for more than 10 min. Thus, exclusively skin-breathing Ambystoma cannot increase cutaneous gas exchange to compensate for the elimination of pulmonary and buccopharyngeal respiration; locomotor stamina suffers accordingly. Small salamanders can apparently increase cutaneous gas exchange during activity, although large salamanders cannot, because cutaneous diffusing capacity and the resting oxygen requirement approach one another with increasing body size; the skin of large salamanders apparently has a limited scope for aerobic activity.

Permeance to oxygen of detached Capsicum annuum fruit

2000 ◽  
Vol 40 (3) ◽  
pp. 457 ◽  
Author(s):  
J. Bower ◽  
B. D. Patterson ◽  
J. J. Jobling
Keyword(s):  
Oxygen Consumption ◽  
Gas Exchange ◽  
Capsicum Annuum ◽  
Oxygen Concentration ◽  
Concentration Gradient ◽  
Gas Diffusion ◽  
Major Barrier ◽  
Capsicum Annuum L ◽  
Rate Of Oxygen Consumption ◽  
Low Rate

The internal oxygen concentration and rate of oxygen consumption of detached capsicum fruits (Capsicum annuum L.) were monitored over several days. From this their overall permeance to oxygen was calculated. When wax was applied to the pedicel and its scar, permeance was reduced by 80–90%, indicating that most gas exchange occurred through this area. Readings from O2 sensors attached to the skins of the fruits were compared to those from O2 sensors inserted into the fruit cavity. These indicated that the cuticle was the major barrier to gas diffusion and that there was a concentration gradient through the capsicum flesh. Permeance of the cuticle was found to be about 0.64 x 10–4 mol O2/Pa.m2.s, while permeance to CO2 was 2–3 times higher. This suggests that the cuticle is composed of a coherent film. The low rate of gas diffusion through capsicum cuticle may allow recycling of respired CO2 by photosynthesis in the flesh before harvest.

scholarly journals Stimulation of Oxygen Consumption with Fluid Absorption in Insect Recta

1982 ◽  
Vol 101 (1) ◽  
pp. 233-254
Author(s):  
D.F. HOULIHAN ◽  
D. SELL
Keyword(s):  
Oxygen Consumption ◽  
Time Course ◽  
Fluid Injection ◽  
Fluid Absorption ◽  
Fluid Uptake ◽  
Local Osmosis ◽  
Before And After ◽  
Rate Of Oxygen Consumption ◽  
Stimulation Of

The oxygen consumption of excised abdomens of cockroaches and locusts has been measured before and after the injection of fluids into the ligated recta. Fluid injection caused a transient stimulation of oxygen consumption of up to 30% of the resting rate. The extra amount of oxygen consumed is positively correlated with the osmolality of the fluid injected and the amount of fluid absorbed. Parallel experiments were carried out on the time course of fluid uptake; these experiments revealed a correlation first between a rapid increase in fluid absorption and stimulation of oxygen consumption, and secondly between the final resting rate of oxygen consumption and a slower absorption of fluid. Locusts take up fluid at double the rate of cockroaches and have double the stimulation in oxygen consumption following fluid injection. In locusts the increases in oxygen consumption can also be correlated with the net movement of Na+, K+and Cl− from the rectum. The stimulation of oxygen consumption during fluid uptake is discussed in relation to the local osmosis model for fluid uptake.

scholarly journals Functional conflicts between feeding and gas exchange in suspension-feeding tadpoles, Xenopus laevis

1984 ◽  
Vol 110 (1) ◽  
pp. 91-98 ◽  
Author(s):  
M. E. Feder ◽  
D. B. Seale ◽  
M. E. Boraas ◽  
R. J. Wassersug ◽  
A. G. Gibbs
Keyword(s):  
Oxygen Consumption ◽  
Gas Exchange ◽  
Xenopus Laevis ◽  
Suspension Feeding ◽  
Air Breathing ◽  
Aerial Respiration ◽  
Metabolic Requirement ◽  
Rate Of Oxygen Consumption ◽  
Food Particles ◽  
Hypoxic Water

Air-breathing tadpoles of Xenopus laevis (Amphibia: Anura) use buccopharyngeal surfaces for both gas exchange and capture of food particles in the water. In dense food suspensions, tadpoles decrease ventilation of the buccopharynx and increase air breathing. The lung ventilatory frequency is elevated even though the rate of oxygen consumption is at or below resting levels, suggesting that the lung hyperventilation reflects compensation for decreased buccopharyngeal respiration rather than an increased metabolic requirement. If tadpoles in hypoxic water are prevented from breathing air, they increase buccopharyngeal respiration at the expense of feeding. Aerial respiration evidently permits the buccopharyngeal surfaces to be used primarily for food entrapment.

Cardiac effects of hypoxia in the neotenous tiger salamanderAmbystoma tigrinum

2002 ◽  
Vol 205 (12) ◽  
pp. 1725-1734 ◽  
Author(s):  
Tom McKean ◽  
Guolian Li ◽  
Kong Wei
Keyword(s):  
Cardiac Output ◽  
Oxygen Consumption ◽  
Oxygen Concentration ◽  
Mechanical Performance ◽  
Cardiac Mass ◽  
Differentially Expressed ◽  
Representational Difference Analysis ◽  
Ambystoma Tigrinum ◽  
Rate Of Oxygen Consumption ◽  
Aquatic Salamanders

SUMMARYThe aquatic form of the tiger salamander Ambystoma tigrinum lives in high-altitude ponds and is exposed to a hypoxic environment that may be either chronic or intermittent. In many animal species, exposure to hypoxia stimulates cardiac output and is followed by an increase in cardiac mass. The working hypothesis of the present study was that the hearts of these aquatic salamanders exposed to 10-14 days of 5 % oxygen in a laboratory setting would become larger and would differentially express proteins that would help confer tolerance to hypoxia. During exposure to hypoxia, cardiac output increased, as did hematocrit. Cardiac mass also increased, but mitotic figures were not detected in the cardiac myocytes of colchicine-injected animals. The mass increase was probably due to hypertrophy, although a very slow rate of hyperplasia cannot be ruled out. Representational difference analysis indicated that at least 14 mRNAs were expressed in hearts from the hypoxic animals that were not expressed in hearts from normoxic animals. The differentially expressed genes were cloned and sequenced and confirmed as coming from the ventricles of the hypoxic salamanders. Genes differentially expressed include mitochondrial genes and genes for elongation factor 2, a protein synthesis gene. The mechanical performance of buffer-perfused hearts isolated from normoxic and hypoxic animals did not differ. Acute responses to hypoxia were also measured. The rate of oxygen consumption of unanesthetized salamanders in metabolism chambers decreased when chamber oxygen concentration was reduced below 12 % oxygen. At a chamber oxygen concentration of 4-6 %, the rate of oxygen consumption of the salamanders was reduced to approximately one-third of the normoxic rate.

Diffusing capacity of the lung during hypoxia: role of capillary recruitment

1981 ◽  
Vol 50 (1) ◽  
pp. 165-171 ◽  
Author(s):  
R. L. Capen ◽  
L. P. Latham ◽  
W. W. Wagner
Keyword(s):  
Carbon Monoxide ◽  
Gas Exchange ◽  
Surface Area ◽  
Diffusing Capacity ◽  
Capillary Recruitment ◽  
Pulmonary Capillary ◽  
Hemoglobin Binding ◽  
Before And After

We have used in vivo microscopy to show that airway hypoxia caused pulmonary capillary recruitment. To determine whether the recruited capillaries add to the surface area for gas exchange, we measured the diffusing capacity of the lung for carbon monoxide before and after inducing recruitment with hypoxia. Diffusing capacity increased during hypoxia. However, some increase in diffusing capacity was expected, since there were fewer oxygen molecules to compete with carbon monoxide for hemoglobin-binding sites. To determine the effect of capillary recruitment alone on diffusing capacity, we held hypoxia constant while infusing a vasodilator to diminish recruitment. Diffusing capacity decreased concomitantly as recruitment diminished. These results indicate that our microscopic observations reflect a widespread recruitment that increases the gas exchange surface area.

scholarly journals THE EFFECTS OF CO AND LIGHT ON THE OXYGEN CONSUMPTION AND ON THE PRODUCTION OF CO2 BY GERMINATING SEEDS OF LUPINUS ALBUS

1932 ◽  
Vol 15 (6) ◽  
pp. 655-665 ◽  
Author(s):  
Pei-Sung Tang
Keyword(s):  
Oxygen Consumption ◽  
Gas Exchange ◽  
Lupinus Albus ◽  
Maximum Extent ◽  
Rate Of Oxygen Consumption ◽  
Germinating Seeds

The consumption of oxygen by germinating seeds of Lupinus albus can be reversibly inhibited by CO to a maximum extent of 36 per cent with a mixture of 24 per cent O2 and 76 per cent CO at 18°, in darkness. This inhibition is completely abolished when the seed is illuminated. On returning to air, after a period in the CO-O2 mixture, the rate of oxygen consumption is accelerated to as much as 68 per cent over what it had been previously, in air. The production of CO2 is apparently not inhibited by CO. The bearing of these findings on the study of the rates of gas exchange of the seeds as a function of temperature is discussed.

Oxygen requirement of renal Na-K-ATPase-dependent sodium reabsorption

1977 ◽  
Vol 232 (2) ◽  
pp. F152-F158 ◽  
Author(s):  
Ole M. Sejersted ◽  
Ȗystein Mathisen ◽  
Fredrik Kiil
Keyword(s):  
Oxygen Consumption ◽  
Transport System ◽  
Sodium Transport ◽  
Sodium Reabsorption ◽  
Oxygen Requirement ◽  
Aortic Constriction ◽  
Renal Oxygen Consumption ◽  
Wide Range ◽  
Before And After ◽  
Renal Oxygen

The oxygen requirement of the Na-K-ATPase-dependent sodium transport system was examined in anesthetized dogs infused with 15% mannitol-Ringer solutions at a rate of 35 ml/min. Because of renal vasodilatation and abolished autoregulation, filtered sodium (FNa) could be varied over a wide range by progressive aortic constriction. Sodium reabsorption.(RNa and renal oxygen consumption (RVo2) varied in proportion to FNa (r> 0.9). Ouabain, which inhibits Na-K-ATPases reduced RVo2 by 45 ± 6%. During subsequent aortic constriction, the ratio ΔRNa/ΔFNa averaged 0.45 (glomerulotubular balance) (r> 0.9), whereas RVo2 was not significantly altered. Comparisons of ΔRNa/ΔFNa before and after ouabain administration, indicate that about half of an increase in sodium delivery to the distal nephron is reabsorbed by the Na-K-ATPase-dependent sodium transport system and that ΔRNa/ΔRVo2 (Na/O2 ratio) of this system averages 14.5 ± 1.3. This Na/O2 ratio corresponds to 2.4 sodium ions transported per ATP dephosphorylated as found in other tissues. autoregulation; ATP; dog; glomerular filtration rate; mannitol; ouabain; renal blood flow; renal oxygen consumption Submitted on February 24, 1976

Effect of Intramuscular Administration of Antibiotics on the Oxygen Consumption of Normal and Hyperthyroid Rats

1957 ◽  
Vol 192 (1) ◽  
pp. 73-75 ◽  
Author(s):  
G. R. Vogel ◽  
S. M. Hauge ◽  
F. N. Andrews
Keyword(s):  
Oxygen Consumption ◽  
Oral Administration ◽  
Intramuscular Injection ◽  
Endocrine System ◽  
Penicillin G ◽  
Albino Rats ◽  
Stomach Tube ◽  
Procaine Penicillin ◽  
Before And After ◽  
Rate Of Oxygen Consumption

The oxygen consumption of normal and hyperthyroid albino rats was measured before and after the intramuscular injection of 1.2 mg (0.2 ml of solution) of procaine penicillin G, Aureomycin or Ilotycin. The final measurements were observed at either 1- or 3-hour intervals after the injection. The antibiotics caused a statistically significant decrease in the rate of oxygen consumption in both normal and hyperthyroid rats. This effect diminished with time. Similar effects were observed with procaine penicillin G after oral administration by stomach tube. It is suggested that antibiotics may somehow influence the endocrine system, possibly the level of circulating thyroxin. Such studies are in progress.

Oxygen Consumption in Platelets of Newborn Infants before and after Stimulation by Thrombin.

1976 ◽  
Vol 35 (03) ◽  
pp. 712-716 ◽  
Author(s):  
D. Del Principe ◽  
G Mancuso ◽  
A Menichelli ◽  
G Maretto ◽  
G Sabetta
Keyword(s):  
Oxygen Consumption ◽  
Cord Blood ◽  
Umbilical Cord ◽  
Newborn Infant ◽  
Umbilical Cord Blood ◽  
Newborn Infants ◽  
O2 Consumption ◽  
Adult Control ◽  
Healthy Newborn ◽  
Before And After

SummaryThe authors compared the oxygen consumption in platelets from the umbilical cord blood of 36 healthy newborn infants with that of 27 adult subjects, before and after thrombin addition (1.67 U/ml). Oxygen consumption at rest was 6 mμmol/109/min in adult control platelets and 5.26 in newborn infants. The burst in oxygen consumption after thrombin addition was 26.30 mμmol/109/min in adults and 24.90 in infants. Dinitrophenol did not inhibit the burst of O2 consumption in platelets in 8 out of 10 newborn infants, while the same concentration caused a decrease in 9 out of 10 adult subjects. Deoxyglucose inhibited the burst in O2 consumption in newborn infant and adult platelets by about 50%. KCN at the concentration of 10−4 M completely inhibited basal oxygen consumption but did not completely inhibit the burst after thrombin. At the concentration of 10−3 M, it inhibited both basal O2 consumption and the burst in infants and adult subjects.

Sign in / Sign up

Export Citation Format

Share Document