Exercise and forced submergence in the pond slider (Trachemys scripta) and softshell turtle (Apalone ferox): influence on bimodal gas exchange, diving behaviour and blood acid-base status

1999 ◽  
Vol 202 (3) ◽  
pp. 267-278 ◽  
Author(s):  
B. Bagatto ◽  
R.P. Henry
Keyword(s):  
Gas Exchange ◽  
Metabolic Stress ◽  
Respiratory Acidosis ◽  
Diving Behaviour ◽  
Trachemys Scripta ◽  
Acid Base ◽  
Aerial Respiration ◽  
Acid Base Status ◽  
Softshell Turtle ◽  
Apalone Ferox

The dynamics of bimodal respiration, diving behaviour and blood acid-base status in the softshell turtle Trachemys scripta and the pond slider Apalone ferox were investigated at rest and under conditions of stress induced by exercise and forced submergence. During periods of forced submergence, only A. ferox doubled its aquatic gas exchange rate. Both A. ferox and T. scripta increased their aerial gas exchange profoundly following exercise and forced submergence, a pattern indicative of increased anaerobic respiration. Emersion duration increased significantly in A. ferox following forced submergence, and mean apnoeic time decreased significantly in A. ferox following exercise, indicating that a larger proportion of time at the surface was spent ventilating. Also, A. ferox maintained a one-breath breathing bout regardless of treatment. Submergence produced a respiratory acidosis in the plasma of approximately 0.2 pH units in magnitude in T. scripta and a mixed respiratory/metabolic acidosis of 0.4 pH units in A. ferox. Exercise induced an acidosis of 0.2 pH units of primarily metabolic origin in both species. Intra-erythrocyte pH was also reduced in both species in response to submergence and exercise. Both intracellular and extracellular acidoses were more severe and longer lasting in A. ferox after each treatment. Plasma [HCO3-] decreased by 25 % in both species following exercise, but only in A. ferox following submergence. Plasma lactate concentrations increased by equal amounts in each species following exercise; however, they returned to resting concentrations sooner in T. scripta than in A. ferox. A. ferox had significantly higher lactate levels than T. scripta following forced submergence as well as a slower recovery time. A. ferox, which is normally a good bimodal gas exchanger at rest, utilizes aerial respiration to a greater extent when under respiratory and/or metabolic stress. T. scripta, although almost entirely dependent on aerial respiration, is physiologically better able to deal with the respiratory and metabolic stresses associated with both forced submergence and exercise.

Acid-base status and spiracular control during discontinuous ventilation in grasshoppers

1995 ◽  
Vol 198 (8) ◽  
pp. 1755-1763 ◽  
Author(s):  
J Harrison ◽  
N Hadley ◽  
M Quinlan
Keyword(s):  
Gas Exchange ◽  
Respiratory Physiology ◽  
Acid Base ◽  
Threshold Levels ◽  
Lubber Grasshopper ◽  
Open Phase ◽  
Internal Co2 ◽  
Acid Base Status

Many insects ventilate discontinuously when quiescent, exhibiting prolonged periods during which little or no gas exchange occurs. We investigated the consequences of discontinuous ventilation (DV) on haemolymph acid­base status and tested whether spiracular opening during DV is due to changes in internal gas tensions in the western lubber grasshopper Taeniopoda eques. At 15 °C, resting T. eques exhibited interburst periods of about 40 min. During the interburst period, haemolymph PCO2 rose from 1.8 to 2.26 kPa, with minimal acidification of haemolymph. Animals in atmospheres in which PCO2 was 2 kPa or below continued to exhibit DV, while atmospheres in which PCO2 was 2.9 kPa or above caused cessation of DV. These data indicate that accumulation of internal CO2 to threshold levels between 2 and 2.9 kPa induces spiracular opening in grasshoppers. In contrast to the situation in lepidopteran pupae, variation in atmospheric PO2 had no effect on interburst duration. Relative to lepidopteran pupae, the internal PCO2 of grasshoppers during DV is threefold lower, the PCO2 required for triggering spiracular opening is also threefold lower, and the open phase spiracular conductance is at least tenfold higher, demonstrating that considerable diversity exists in these aspects of insect respiratory physiology.

Anesthetic effects on liver and muscle glycogen concentrations: rest and postexercise

1989 ◽  
Vol 66 (6) ◽  
pp. 2895-2900 ◽  
Author(s):  
T. I. Musch ◽  
B. S. Warfel ◽  
R. L. Moore ◽  
D. R. Larach
Keyword(s):  
Skeletal Muscles ◽  
Respiratory Acidosis ◽  
Blood Gases ◽  
Arterial Blood Gases ◽  
Acid Base ◽  
Arterial Lactate ◽  
Arterial Pco2 ◽  
Arterial Blood ◽  
Acid Base Status ◽  
Gastrocnemius Muscles

We compared the effects of three different anesthetics (halothane, ketamine-xylazine, and diethyl ether) on arterial blood gases, acid-base status, and tissue glycogen concentrations in rats subjected to 20 min of rest or treadmill exercise (10% grade, 28 m/min). Results demonstrated that exercise produced significant increases in arterial lactate concentrations along with reductions in arterial Pco2 (PaCO2) and bicarbonate concentrations in all rats compared with resting values. Furthermore, exercise produced significant reductions in the glycogen concentrations in the liver and soleus and plantaris muscles, whereas the glycogen concentrations found in the diaphragm and white gastrocnemius muscles were similar to those found at rest. Rats that received halothane and ketamine-xylazine anesthesia demonstrated an increase in Paco2 and a respiratory acidosis compared with rats that received either anesthesia. These differences in arterial blood gases and acid-base status did not appear to have any effect on tissue glycogen concentrations, because the glycogen contents found in liver and different skeletal muscles were similar to one another cross all three anesthetic groups. These data suggest that even though halothane and ketamine-xylazine anesthesia will produce a significant amount of ventilatory depression in the rat, both anesthetics may be used in studies where changes in tissue glycogen concentrations are being measured and where adequate general anesthesia is required.

scholarly journals The effects of post-operative oxygen supply on blood oxygenation and acid-base status in rats anaesthetized with fentanyl/fluanisone and midazolam

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255829
Author(s):  
Leander Gaarde ◽  
Stefanie Kolstrup ◽  
Peter Bollen
Keyword(s):  
Oxygen Saturation ◽  
Oxygen Supply ◽  
Respiratory Acidosis ◽  
Blood Oxygenation ◽  
Acid Base ◽  
Blood Oxygen Saturation ◽  
Arterial Blood ◽  
Post Operative Period ◽  
Significant Difference ◽  
Acid Base Status

In anaesthetic practice the risk of hypoxia and arterial blood gas disturbances is evident, as most anaesthetic regimens depress the respiratory function. Hypoxia may be extended during recovery, and for this reason we wished to investigate if oxygen supply during a one hour post-operative period reduced the development of hypoxia and respiratory acidosis in rats anaesthetized with fentanyl/fluanisone and midazolam. Twelve Sprague Dawley rats underwent surgery and were divided in two groups, breathing either 100% oxygen or atmospheric air during a post-operative period. The peripheral blood oxygen saturation and arterial acid-base status were analyzed for differences between the two groups. We found that oxygen supply after surgery prevented hypoxia but did not result in a significant difference in the blood acid-base status. All rats developed respiratory acidosis, which could not be reversed by supplemental oxygen supply. We concluded that oxygen supply improved oxygen saturation and avoided hypoxia but did not have an influence on the acid-base status.

Evaluation of bicarbonate transport in rat distal tubule: effects of acid-base status

1982 ◽  
Vol 243 (4) ◽  
pp. F335-F341 ◽  
Author(s):  
M. S. Lucci ◽  
L. R. Pucacco ◽  
N. W. Carter ◽  
T. D. DuBose
Keyword(s):  
Metabolic Acidosis ◽  
Respiratory Acidosis ◽  
Distal Tubule ◽  
Bicarbonate Transport ◽  
Acid Base Balance ◽  
Acid Base ◽  
Bicarbonate Reabsorption ◽  
Base Balance ◽  
Acid Base Status ◽  
Acute Metabolic Acidosis

Previous micropuncture studies utilizing indirect methods to estimate bicarbonate transport in the rat superficial distal tubule have indicated that the distal bicarbonate reabsorptive process normally operates well below the saturation level. Recent studies from our laboratory failed to demonstrate a spontaneous acid disequilibrium pH in this segment, implying that the bicarbonate reabsorptive rate was less than previously estimated. The purpose of the present experiments were 1) to measure the rate of absolute bicarbonate reabsorption by the rat superficial distal tubule while controlling bicarbonate delivery, and 2) to examine the effects of alterations in acid-base status on the rate of bicarbonate reabsorption. Five groups of rats in different states of acid-base balance were studied. No significant bicarbonate reabsorption was detected in the control hydropenic, combined respiratory acidosis-metabolic alkalosis, acute respiratory acidosis, or acute metabolic acidosis groups. In contrast, metabolic acidosis of 3 days duration resulted in a significant bicarbonate reabsorptive rate of 52.6 +/- 13.9 pmol . mm-1 . min-1. The observation of significant bicarbonate reabsorption in the distal tubule only during chronic metabolic acidosis of 3 days duration is compatible with adaptation of this normally low-capacity segment to chronic changes in systemic acid-base states.

ADJUSTMENT OF VENTILATION, INTRAPULMONARY GAS EXCHANGE, AND ACID-BASE BALANCE DURING THE FIRST DAY OF LIFE

PEDIATRICS ◽  
1964 ◽  
Vol 33 (5) ◽  
pp. 682-693
Author(s):  
L. Samuel Prod'hom ◽  
Henry Levison ◽  
Ruth B. Cherry ◽  
James E. Drorbaugh ◽  
John P. Hubbell ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Respiratory Distress ◽  
Respiratory Acidosis ◽  
Acid Base Balance ◽  
Acid Base ◽  
Infants Of Diabetic Mothers ◽  
Arterial Blood ◽  
Physiologic Dead Space ◽  
Base Balance ◽  
Diabetic Mothers

Determinations of blood gases and of acid-base balance were done in umbilical vein and artery blood at birth and in arterial blood at the age of 20 minutes in 20 infants of diabetic mothers. All were born by cesarean section, 18 of them between 36 and 37 weeks gestation. None showed respiratory distress at any time. Ventilation, gaseous metabolism, functional residual capacity, intrapulmonary gas exchange, and acid-base balance were determined at the age of 1, 4, and 24 hours in these 20 infants. The results indicate the following conclusions with regard to infants of diabetic mothers. 1. Adjustment of ventilation to perfusion in the lung appears to be complete at 4 hours of life. 2. Throughout the first 24 hours there is a persistence of an over-all true right to left shunt of approximately 20-25% of the total cardiac output. The exact localization of this shunt is unknown. 3. Acid-base balance in cord blood and in arterial blood during the first day of life in infants of diabetic mothers differs only slightly from that of infants of nondiabetic mothers. At 1 and 4 hours of age there is some persistence of a slight respiratory acidosis. 4. At 24 hours infants of diabetic mothers have the usual low arterial Pco2 of other newborn infants, but a ventilation equivalent of 16.5, which is normal for adults. 5. Although 6 of the 17 infants studied at 4 hours have shown a respiratory rate above 60 without other signs of respiratory distress, these infants with high rates had small tidal volumes, high physiologic dead-space/tidal volume ratios, and relatively little increase in minute volume.

Acid-base status affects gas exchange in canine oleic acid pulmonary edema

1991 ◽  
Vol 260 (4) ◽  
pp. H1080-H1086 ◽  
Author(s):  
S. Brimioulle ◽  
J. L. Vachiery ◽  
P. Lejeune ◽  
M. Leeman ◽  
C. Melot ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Metabolic Acidosis ◽  
Gas Exchange ◽  
Pulmonary Edema ◽  
Sulfur Hexafluoride ◽  
Respiratory Acidosis ◽  
Pulmonary Gas Exchange ◽  
Intrapulmonary Shunt ◽  
Pulmonary Hemodynamics ◽  
Acid Base Status

The effects of acidosis and alkalosis on pulmonary gas exchange were studied in 32 pentobarbital sodium-anesthetized intact dogs after induction of oleic acid (0.06 ml/kg) pulmonary edema. Gas exchange was assessed at constant ventilation and constant cardiac output, by venous admixture calculations and by intrapulmonary shunt measurements using the sulfur hexafluoride (SF6) method. Metabolic acidosis (pH 7.20) and alkalosis (pH 7.60) were induced with HCl and Carbicarb (isosmolar Na2CO3 and NaHCO3), respectively. Hypercapnia was induced by adding inspiratory CO2, whereas pH was allowed to change (respiratory acidosis, pH 7.20) or maintained constant (isolated hypercapnia). Mean intrapulmonary shunt and pulmonary arterial minus wedge pressure difference, respectively, changed from 44 to 33% (P less than 0.05) and from 9 to 10 mmHg (P greater than 0.05) in metabolic acidosis, from 44 to 62% (P less than 0.001) and from 12 to 8 mmHg (P less than 0.01) in metabolic alkalosis, from 40 to 42% (P greater than 0.05) and from 13 to 16 mmHg (P less than 0.05) in respiratory acidosis, from 42 to 52% (P less than 0.05) and from 8 to 12 mmHg (P less than 0.01) in isolated hypercapnia. These results indicate that acidosis, alkalosis, and hypercapnia markedly influence pulmonary gas exchange and/or pulmonary hemodynamics in dogs with oleic acid pulmonary edema.

Roles of gill and red cell carbonic anhydrase in elasmobranch HCO3- and CO2 excretion

1987 ◽  
Vol 253 (3) ◽  
pp. R450-R458 ◽  
Author(s):  
E. R. Swenson ◽  
T. H. Maren
Keyword(s):  
Carbonic Anhydrase ◽  
Respiratory Acidosis ◽  
Red Cell ◽  
Acid Base ◽  
Terrestrial Vertebrates ◽  
Carbonic Anhydrase Inhibition ◽  
Normal Metabolism ◽  
Acid Base Status ◽  
Erythrocyte Carbonic Anhydrase ◽  
Co2 Elimination

We studied the roles of gill and erythrocyte carbonic anhydrase in normal CO2 transfer (metabolic CO2 elimination) and in HCO3- excretion during metabolic alkalosis in the resting and swimming dogfish shark, Squalus acanthias. Gill carbonic anhydrase was selectively inhibited (greater than 98.5%) by 1 mg/kg benzolamide, which caused no physiologically significant red cell carbonic anhydrase inhibition (approximately 40%). Enzyme in both tissues was inhibited by 30 mg/kg methazolamide (greater than 99%). Both drugs caused equivalent reductions in HCO3- excretion following an infusion of 9 mmol/kg NaHCO3 as measured by the rate of fall in plasma HCO3- and by transfer into seawater. Methazolamide (red cell and gill carbonic anhydrase inhibition) caused a respiratory acidosis in fish with normal acid-base status, whereas benzolamide (gill carbonic anhydrase inhibition) did not. The only effect observed with benzolamide in these fish was a small elevation in plasma HCO3-. These findings, taken together, suggest that red cell carbonic anhydrase is required for normal metabolic CO2 elimination by the gill. Although carbonic anhydrase is located in the respiratory epithelium, it appears to have no quantitative role in transfer of metabolic CO2 to the environment, a pattern similar to all terrestrial vertebrates. However, carbonic anhydrase in the gill is crucial to this organ's function in acid-base regulation, both in the excretion of H+ or HCO3- generated in normal metabolism and in various acid-base disturbances.

Relative effects of carbonic anhydrase infusion or inhibition on carbon dioxide transport and acid-base status in the sea lamprey Petromyzon marinus following exercise

1996 ◽  
Vol 199 (4) ◽  
pp. 933-940
Author(s):  
B Tufts ◽  
S Currie ◽  
J Kieffer
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Anhydrase ◽  
Venous Blood ◽  
Extracellular Fluid ◽  
Respiratory Acidosis ◽  
Acid Base ◽  
Carbon Dioxide Transport ◽  
Co2 Transport ◽  
Arterial Blood ◽  
Acid Base Status

In vivo experiments were carried out to determine the relative effects of carbonic anhydrase (CA) infusion or inhibition on carbon dioxide (CO2) transport and acid-base status in the arterial and venous blood of sea lampreys recovering from exhaustive exercise. Infusion of CA into the extracellular fluid did not significantly affect CO2 transport or acid-base status in exercised lampreys. In contrast, infusion of the CA inhibitor acetazolamide resulted in a respiratory acidosis in the blood of recovering lampreys. In acetazolamide-treated lampreys, the post-exercise extracellular pH (pHe) of arterial blood was significantly lower than that in the saline-infused (control) lampreys. The calculated arterial and venous partial pressure of carbon dioxide (PCO2) and the total CO2 concentration in whole blood (CCO2wb) and red blood cells (CCO2rbc) during recovery in the acetazolamide-infused lampreys were also significantly greater than those values in the saline-infused control lampreys. These results suggest that the CO2 reactions in the extracellular compartment of lampreys may already be in equilibrium and that the access of plasma bicarbonate to CA is probably not the sole factor limiting CO2 transport in these animals. Furthermore, endogenous red blood cell CA clearly has an important role in CO2 transport in exercising lampreys.

Acid-Base Relationships in the Blood of the Toad, Bufo Marinus: II. The Effects of Dehydration

1979 ◽  
Vol 82 (1) ◽  
pp. 345-355
Author(s):  
R. G. BOUTILIER ◽  
D. J. RANDALL ◽  
G. SHELTON ◽  
D. P. TOEWS
Keyword(s):  
Water Loss ◽  
Respiratory Acidosis ◽  
Acid Base ◽  
Arterial Blood ◽  
Blood Ph ◽  
Acid Base Status ◽  
Toad Bufo ◽  
Circulating Levels ◽  
Bladder Urine ◽  
Co2 Excretion

Cutaneous CO2 excretion is reduced as the skin dries during dehydration but an increase in breath frequency acts to regulate the arterial blood Pcoco2 and thus pHα. Moreover, the toad does not urinate and water is reabsorbed from the bladder to replace that lost by evaporation at the skin and lung surfaces. The animal does, however, produce a very acid bladder urine to conserve circulating levels of plasma [HCO3-] and this together with an increased ventilation effectively maintains the blood acid-base status for up to 48 h of dehydration in air. Water loss and acid production are presumably also reduced by the animal's behaviour; animals remain still, in a crouched position or in a pile if left in groups. Dehydrated toads are less able than hydrated toads to regulate blood pH during hypercapnia: they hyperventilate and mobilize body bicarbonate stores in much the same fashion as hydrated animals but due to the restrictions on cutaneous CO2 excretion and renal output, there is comparatively little reduction in the PCOCO2 difference between arterial blood and inspired gas thereby resulting in a more severe respiratory acidosis. These factors further contribute to the persistent acidosis which continues even when the animals are returned to air.

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