Metabolic and acid-base changes during selection of warmer water by cold-acclimated fish

1982 ◽  
Vol 242 (1) ◽  
pp. R157-R161
Author(s):  
L. I. Crawshaw ◽  
R. A. Ackerman ◽  
F. N. White ◽  
M. E. Heath

Largemouth bass (Micropterus salmoides) acclimated to 3 degrees C were placed in a thermal gradient. The bass selected the final thermal preferendum of 28 degrees C in about 18 h. The movement into warmer water was initially rapid but became progressively slower. 2) Other bass were acclimated to 8 degrees C, cannulated in the dorsal aorta, and placed in a temperature-controlled chamber. Oxygen uptake, blood pH, and total CO2 were measured as the chamber temperature was increased to 28 degrees C following a time course similar to that followed by bass in the gradient. 3) Oxygen uptake was always elevated above the resting level, and this elevation increased as higher temperatures were encountered. 4) Just prior to placement in the chamber the pH of the arterial blood was 7.98 +/- 0.05 (mean +/- SE). As the temperature was increased neither the pH nor the total CO2 content of the blood exhibited major changes. At temperatures between 26 and 28 degrees C, the pH (8.01 +/- 0.03) was about 0.3 pH units above predicted normal values. 5) During the return to the final thermal preferendum fish experience overall metabolic rates and extracellular acid-base levels that deviate progressively farther from normal resting levels. Neither factor appears likely to be the major determinant of the behavioral response.

1975 ◽  
Vol 38 (6) ◽  
pp. 1067-1072 ◽  
Author(s):  
H. V. Forster ◽  
J. A. Dempsey ◽  
L. W. Chosy

This study has assessed the regulation of arterial blood and cerebrospinal fluid acid-base status in seven healthy men, at 250 m altitude and after 5 and 10–11 days sojourn at 4,300 m altitude (PaO2 = 39 mmHg day 1 to 48 mmHg day 11). We assumed that observed changes in lumbar spinal fluid acid-base status paralleled those in cisternal CSF, under these relatively steady-state conditions. Ventilatory acclimatization during the sojourn (-14 mmHg PaCO2 at day 11) was accompanied by: 1) reductions in [HCO3-] (-5 to -7 meq/1) which were similar in arterial blood and CSF; 2) substantial, yet incomplete, compensation (70–75%) of both CSF and blood pH; and 3) a level of CSF pH which was maintained significantly alkaline (+0.05 +/- 0.01) to normoxic control values. These data at 4,300 m confirmed and extended our previous findings for more moderate conditions of chronic hypoxia. It was postulated that the magnitude and time course of pH compensation in the CSF during chronic hypoxia and/or hypocapnia are determined by corresponding changes in plasma [HCO2-].


PEDIATRICS ◽  
1980 ◽  
Vol 65 (5) ◽  
pp. 1006-1006

In the article "A Diagnostic Approach to Metabolic Acidosis in Children" by Kappy and Morrow (Pediatrics 65:351-356, 1980) on p 351 under "Normal Acid-Base Physiology" the normal arterial blood pH is maintained at 7.40 (H+ = 39.8 nEq/liter not mEq/liter.


1989 ◽  
Vol 141 (1) ◽  
pp. 407-418 ◽  
Author(s):  
Y. TANG ◽  
D. G. McDONALD ◽  
R. G. BOUTILIER

Blood acid-base regulation following exhaustive exercise was investigated in freshwater- (FW) and seawater- (SW) adapted rainbow trout (Salmo gairdneri) of the same genetic stock. Following exhaustive exercise at 10°C, both FW and SW trout displayed a mixed respiratory and metabolic blood acidosis. However, in FW trout the acidosis was about double that of SW trout and arterial blood pH took twice as long to correct. These SW/FW differences were related to the relative amounts of net H+ equivalent excretion to the environmental water, SW trout excreting five times as much as FW trout. The greater H+ equivalent excretion in SW trout may be secondary to changes in the gills that accompany the adaptation from FW to SW. It may also be related to the higher concentrations of HCO3− as well as other exchangeable counter-ions (Na+ and Cl−) in the external medium in SW compared to FW.


1980 ◽  
Vol 84 (1) ◽  
pp. 273-287
Author(s):  
D. G. McDonald ◽  
R. G. Boutilier ◽  
D. P. Toews

Strenuous exercise results in a marked blood acid-base disturbance which is accompanied by large increases in ventilation rate, heart rate and mean arterial blood pressure. Recovery to normal resting values follows an exponential time course with a half-time of approximately 2 h for all parameters except Pa, CO2 and ventilation rate. The latter return to normal by 30 min following the exercise period. Analysis reveals that there is initially a large discrepancy between the quantity of metabolic acids buffered in the blood and the blood lactate levels. The significance of this finding is discussed. Significant changes in the concentrations of chloride, bicarbonate and lactate, in both plasma and erythrocytes, accompany the blood acid-base disturbance. Chloride and bicarbonate appear to be passively distributed between the two compartments according to a Gibbs-Donnan equilibrium whereas lactate only slowly permeates the erythrocyte.


1964 ◽  
Vol 19 (2) ◽  
pp. 319-321 ◽  
Author(s):  
J. W. Severinghaus ◽  
A. Carceleń B.

CSF pH was shown in a prior report to remain essentially constant during 8 days of acclimatization to 3,800 m. In order to further evaluate the possible role of CSF acid-base equilibria in the regulation of respiration, 20 Peruvian Andean natives were studied at altitudes of 3,720–4,820 m. In ten subjects at 3,720 m, means were: CSF pH 7.327, Pco2 43, HCO3- 21.5, Na+ 136, K+ 2.6, Cl- 124, lactate 30 mg/100 ml. Arterial blood: pH 7.43, Pco2 32.5, HCO3- 21.3, Na+ 136, K+ 4.2, Cl- 107, hematocrit 49, SaOO2 89.6. In six subjects at 4,545 m and four at 4,820 m CSF values were not significantly different; mean arterial Pco2 was 32.6 and 32.3, respectively. The only significant variations with altitude were the expected lowering of PaOO2 to 47 and 43.5 mm Hg, and of SaOO2 to 84.2 and 80.7, and increase of hematocrit to 67% and 75%, respectively. The natives differed from recently acclimatized sea-level residents in showing less ventilation (higher Pco2) in response to the existing hypoxia, and less alkaline arterial blood. The difference appears to relate to peripheral chemoreceptor response to hypoxia rather than central medullary chemoreceptor. respiratory regulation at high altitude; chronic acclimatization to altitude; peripheral chemoreceptor response to hypoxia; CSF and medullary respiratory chemoreceptors Submitted on June 12, 1963


1994 ◽  
Vol 14 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Jacques J. Sennesael ◽  
Godelieve C. De Smedt ◽  
Patricia Van der Niepen ◽  
Dierik L. Verbeelen

Objective To assess the possible effects of peritonitis on peritoneal and systemic acid-base status. Design pH, pCO2, lactate, and total leukocyte and differential count were simultaneously determined in the overnight dwell peritoneal dialysis effluent (PDE) and arterial blood in noninfected patients (controls) and on days 1, 3, and 5 from the onset of peritonitis. Setting University multidisciplinary dialysis program. Patients Prospective analysis of 63 peritonitis episodes occurring in 30 adult CAPD patients in a single center. Results In controls, mean (±SD) acid-base parameters were pH 7.41 ±0.05, pCO2 43.5±2.6 mm Hg, lactate 2.5±1.5 mmol/L in the PDE, and pH 7.43±0.04, PaCO2 36.8±3.8 mm Hg, lactate 1.4±0.7 mmol/L in the blood. In sterile (n=6), gram-positive (n=34), and Staphylococcus aureus (n=9) peritonitis PDE pH's on day 1 were, respectively, 7. 29±0.07, 7. 32±0.07, and 7.30±0.08 (p<0.05 vs control). In gram -negative peritonitis (n=14) PDE pH was 7.21 ±0.08 (p<0.05 vs all other groups). A two-to-threefold increase in PDE lactate was observed in all peritonitis groups, but a rise in pCO2 was only seen in gram -negative peritonitis. Acid-base profile of PDE had returned to control values by day 3 in sterile, gram -positive and Staphylococcus aureus peritonitis and by day 5 in gramnegative peritonitis. Despite a slight increase in plasma lactate on the first day of peritonitis, arterial blood pH was not affected by peritonitis. Conclusion PDE pH is decreased in continuous ambulatory peritoneal dialysis (CAPD) peritonitis, even in the absence of bacterial growth. In gram-negative peritonitis, PDE acidosis is more pronounced and prolonged, and pCO2 is markedly increased. Arterial blood pH is not affected by peritonitis.


2007 ◽  
Vol 292 (3) ◽  
pp. G899-G904 ◽  
Author(s):  
Markus Sjöblom ◽  
Olof Nylander

When running in vivo experiments, it is imperative to keep arterial blood pressure and acid-base parameters within the normal physiological range. The aim of this investigation was to explore the consequences of anesthesia-induced acidosis on basal and PGE2-stimulated duodenal bicarbonate secretion. Mice (strain C57bl/6J) were kept anesthetized by a spontaneous inhalation of isoflurane. Mean arterial blood pressure (MAP), arterial acid-base balance, and duodenal mucosal bicarbonate secretion (DMBS) were studied. Two intra-arterial fluid support strategies were used: a standard Ringer solution and an isotonic Na2CO3 solution. Duodenal single perfusion was used, and DMBS was assessed by back titration of the effluent. PGE2 was used to stimulate DMBS. In Ringer solution-infused mice, isoflurane-induced acidosis became worse with time. The blood pH was 7.15–7.21 and the base excess was about −8 mM at the end of experiments. The continuous infusion of Na2CO3 solution completely compensated for the acidosis. The blood pH was 7.36–7.37 and base excess was about 1 mM at the end of the experiment. Basal and PGE2-stimulated DMBS were markedly greater in animals treated with Na2CO3 solution than in those treated with Ringer solution. MAP was slightly higher after Na2CO3 solution infusion than after Ringer solution infusion. We concluded that isoflurane-induced acidosis markedly depresses basal and PGE2-stimulated DMBS as well as the responsiveness to PGE2, effects prevented by a continuous infusion of Na2CO3. When performing in vivo experiments in isoflurane-anesthetized mice, it is recommended to supplement with a Na2CO3 infusion to maintain a normal acid-base balance.


1979 ◽  
Vol 82 (1) ◽  
pp. 357-365
Author(s):  
R. G. BOUTILIER ◽  
D. J. RANDALL ◽  
G. SHELTON ◽  
D. P. TOEWS

When Bufo marinus burrows, the skin becomes intimately surrounded by substrate but the nares always remain exposed to the surface air. Upon entering into a state of dormancy the animal hypoventilates and this together with the loss of the skin as a respiratory site results in a rise in arterial blood Pcoco2 despite a probable decline in metabolism. Even though lung ventilation falls, the toad regulates blood pH and the respiratory acidosis is progressively compensated for by a progressive increase in plasma [HCO3-] along the course of an elevated PCOCO2 isopleth. At steady state, the acidosis is fully compensated for by a new equilibrium ratio of HCO3- to PCOCO2 at the same pH as the non-burrowed animal. Arousal from the dormant state at this time results in a marked lung hyperventilation and a sharp decline in body CO2 stores


Author(s):  
Michael M. Tymko ◽  
Christopher K. Willie ◽  
Connor A. Howe ◽  
Ryan L. Hoiland ◽  
Rachel Stone ◽  
...  

High-altitude exposure results in a hyperventilatory-induced respiratory alkalosis followed by renal compensation (bicarbonaturia) to return arterial blood pH(a) toward sea-level values. However, acid-base balance has not been comprehensively examined in both lowlanders and indigenous populations - where the latter are thought to be fully adapted to high-altitude. The purpose of this investigation was to compare acid-base balance between acclimatizing lowlanders, and Andean and Sherpa highlanders at various altitudes (~3,800, ~4,300, and ~5,000 m). We compiled data collected across five independent high-altitude expeditions and report the following novel findings: 1) at 3,800 m, Andeans (n=7) had elevated pHa compared to Sherpas (n=12; P<0.01), but not to lowlanders (n=16; nine days acclimatized; P=0.09); 2) at 4,300 m, lowlanders (n=16; 21 days acclimatized) had elevated pHa compared to Andeans (n=32) and Sherpas (n=11; both P<0.01), and Andeans had elevated pHa compared to Sherpas (P=0.01); and 3) at 5,000 m, lowlanders (n=16; 14 days acclimatized) had higher pHa compared to both Andeans (n=66) and Sherpas (n=18; P<0.01, and P=0.03, respectively), and Andean and Sherpa highlanders had similar blood pHa (P=0.65). These novel data characterize acid-base balance acclimatization and adaptation to various altitudes in lowlanders and indigenous highlanders.


PEDIATRICS ◽  
1964 ◽  
Vol 34 (2) ◽  
pp. 192-197
Author(s):  
Gillian Gandy ◽  
Lotte Grann ◽  
Nicholas Cunningham ◽  
Karlis Adamsons ◽  
L. Stanley James

This study has demonstrated that in healthy newborn infants over 3 hours of age, pH aIld Pco2 of "arterialized" capillary samples reflect closely the values of arterial blood. Prior to this age and in infants with impaired cardiopulmonary function the agreement between samples from the two sources is less satisfactory. In these infants only limited conclusions regarding acid-base state and alveolar ventilation can be drawn from capillary blood pH and Pco2. The metabolic component of acid-base disturbances can be assessed with a fair degree of accuracy even if the capillary sample is "venous" in character.


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