scholarly journals Anaerobic Metabolism and Changes in Acid—Base Status: Quantitative Interrelationships and PH Regulation in the Marine Worm Sipunculus Nudus

1987 ◽  
Vol 131 (1) ◽  
pp. 89-105
Author(s):  
HANS-OTTO PÖRTNER
Keyword(s):  
Anaerobic Metabolism ◽  
Ph Value ◽  
Ph Regulation ◽  
Proton Exchange ◽  
Acid Base ◽  
Base Parameters ◽  
Sipunculus Nudus ◽  
Theoretical Predictions ◽  
Acid Base Status ◽  
Proton Generation

The quantitative influence of anaerobic metabolism on acid—base status and on acid-base regulation is investigated in Sipunculus nudus L. Proton generation by metabolism is calculated from theoretical predictions. The quantitative comparison of metabolic protons with non-respiratory protons found in the acid—base status is performed assuming a simplified model of the total animal. Taking the protonequivalent ion exchange between animals and ambient water into account, changes in the anaerobic acid—base status can be explained exclusively by proton generation in metabolism. It is concluded that the classical concept of acid—base physiology is adequate and that the consideration of strong ions is not required for a quantitative treatment of the acid—base status. The hypothesis that a quantitative correlation exists between metabolic and acid—base events is tested by comparing changes in acid—base status and in metabolism in animals exhibiting different metabolic rates. For this purpose, a method is developed for the calculation of intracellular pH from metabolite concentrations and extracellular acid—base parameters. Proton exchange between intra-and extracellular compartments, which is found to depend upon the total amount of accumulated non-respiratory protons, demonstrates that pHi is regulated even during anaerobiosis. The defended pH, value, however, is lower during anaerobiosis than during subsequent recovery. Note: Address for reprint requests

White Muscle Intracellular Acid-Base and Lactate Status Following Exhaustive Exercise: A Comparison between Freshwater- and Sea Water- Adapted Rainbow Trout

1991 ◽  
Vol 156 (1) ◽  
pp. 153-171 ◽  
Author(s):  
YONG TANG ◽  
ROBERT G. BOUTILIER
Keyword(s):  
Rainbow Trout ◽  
White Muscle ◽  
Sea Water ◽  
Ph Regulation ◽  
Recovery Period ◽  
Exhaustive Exercise ◽  
Acid Base ◽  
Post Exercise ◽  
Acid Base Status ◽  
Intracellular Acid

The intracellular acid-base status of white muscle of freshwater (FW) and seawater (SW) -adapted rainbow trout was examined before and after exhaustive exercise. Exhaustive exercise resulted in a pronounced intracellular acidosis with a greater pH drop in SW (0.82 pH units) than in FW (0.66 pH units) trout; this was accompanied by a marked rise in intracellular lactate levels, with more pronounced increases occurring in SW (54.4 mmoll−1) than in FW (45.7 mmoll−1) trout. Despite the more severe acidosis, recovery was faster in the SW animals, as indicated by a more rapid clearance of metabolic H+ and lactate loads. Compartmental analysis of the distribution of metabolic H+ and lactate loads showed that the more rapid recovery of pH in SW trout could be due to (1) their greater facility for excreting H+ equivalents to the environmental water [e.g. 15.5 % (SW) vs 5.0 % (FW) of the initial H+ load was stored in external water at 250 min post-exercise] and, to a greater extent, (2) the more rapid removal of H+, facilitated via lactate metabolism in situ (white muscle) and/or the Cori cycle (e.g. heart, liver). The slower pH recovery in FW trout may also be due in part to greater production of an ‘unmeasured acid’ [maximum approx. 8.5 mmol kg−1 fish (FW) vs approx. 6 mmol kg−1 fish (SW) at 70–130 min post-exercise] during the recovery period. Furthermore, the analysis revealed that H+-consuming metabolism is quantitatively the most important mechanism for the correction of an endogenously originating acidosis, and that extracellular pH normalization gains priority over intracellular pH regulation during recovery of acid-base status following exhaustive exercise.

scholarly journals Metabolic and volume status evaluation of hemodialysis patients with and without residual renal function in the long interdialytic interval

2019 ◽  
Vol 41 (4) ◽  
pp. 481-491 ◽  
Author(s):  
Lenina Ludimila Sampaio de Almeida ◽  
Luís Henrique Bezerra Cavalanti Sette ◽  
Fernando Luiz Affonso Fonseca ◽  
Leila Silveira Vieira da Silva Bezerra ◽  
Francisco Hélio Oliveira Júnior ◽  
...  
Keyword(s):  
Renal Function ◽  
Serum Potassium ◽  
Ph Value ◽  
Residual Renal Function ◽  
Acid Base ◽  
Serum Samples ◽  
Cross Sectional ◽  
Interdialytic Weight Gain ◽  
Base Disorder ◽  
Acid Base Status

Abstract Introduction: It is unclear whether residual renal function (RRF) in dialysis patients can attenuate the metabolic impact of the long 68-hour interdialytic interval, in which water, acid, and electrolyte accumulation occurs. Objective: to evaluate serum electrolyte levels, water balance, and acid-base status in dialytic patients with and without RRF over the long interdialytic interval (LII). Methodology: this was a single-center, cross-sectional, and analytical study that compared patients with and without RRF, defined by diuresis above 200 mL in 24 hours. Patients were weighed and serum samples were collected for biochemical and gasometric analysis at the beginning and at the end of the LII. Results: 27 and 24 patients with and without RRF were evaluated, respectively. Patients without RRF had a higher increase in serum potassium during the LII (2.67 x 1.14 mEq/L, p < 0.001), reaching higher values at the end of the study (6.8 x 5.72 mEq/L, p < 0.001) and lower pH value at the beginning of the interval (7.40 x 7.43, p = 0.018). More patients with serum bicarbonate < 18 mEq/L (50 x 14.8%, p = 0.007) and mixed acid-base disorder (57.7 x 29.2%, p = 0.042), as well as greater interdialytic weight gain (14.67 x 8.87 mL/kg/h, p < 0.001) and lower natremia (137 x 139 mEq/L, p = 0.02) at the end of the interval. Calcemia and phosphatemia were not different between the groups. Conclusion: Patients with RRF had better control of serum potassium, sodium, acid-base status, and volemia throughout the LII.

scholarly journals Metabolism and energetics in squid (Illex illecebrosus, Loligo pealei) during muscular fatigue and recovery

1993 ◽  
Vol 265 (1) ◽  
pp. R157-R165 ◽  
Author(s):  
H. O. Portner ◽  
D. M. Webber ◽  
R. K. O'Dor ◽  
R. G. Boutilier
Keyword(s):  
Energy Production ◽  
Detrimental Effect ◽  
Anaerobic Metabolism ◽  
Energy Status ◽  
Acid Base ◽  
Mantle Tissue ◽  
Anaerobic Energy ◽  
Acid Base Status ◽  
Postexercise Recovery ◽  
Loligo Pealei

The concentrations of intermediate and end products of anaerobic energy metabolism and of free amino acids were determined in mantle musculature and blood sampled from cannulated, unrestrained squid (Loligo pealei, Illex illecebrosus) under control conditions, after fatigue from increasing levels of exercise, and during postexercise recovery. Phosphagen depletion, accumulation of octopine (more so in Illex than in Loligo), and accumulation of succinate indicate that anaerobic metabolism contributes to energy production before fatigue. Proline was a substrate of metabolism in Loligo, as indicated by its depletion in the mantle. In both species, there was no evidence of catabolism of ATP beyond AMP. A comparison of the changes in the free and total levels of adenylates and the phosphagen indicates an earlier detrimental effect of fatigue on the energy status in Loligo. The acidosis provoked by octopine formation in Illex was demonstrated to promote the use of the phosphagen and to protect the free energy change of ATP such that the anaerobic scope of metabolism during swimming is extended and expressed more in Illex than in Loligo. In both species, there was no decrease in the sum of phospho-L-arginine, octopine, and L-arginine, and thus no release of octopine from the mantle, thereby supporting our earlier claim that octopine and associated protons are recycled in the mantle tissue. Overall, the metabolic strategy of Loligo is much less disturbing for the acid-base status. This strategy and the alternative strategy of Illex to keep acidifying protons in the tissue may be important for the protection of hemocyanin function in the two species.

Acid-base status of fish at different temperatures

1984 ◽  
Vol 246 (4) ◽  
pp. R452-R459 ◽  
Author(s):  
J. N. Cameron
Keyword(s):  
Ictalurus Punctatus ◽  
Ph Regulation ◽  
Water Channel ◽  
Strong Ion Difference ◽  
Acid Base ◽  
Practical Advantage ◽  
Co2 Partial Pressure ◽  
Different Temperatures ◽  
Acid Base Status ◽  
Future Work

In the water-breathing fishes, rising temperatures are accompanied by progressive reduction in pH, reductions in bicarbonate concentration, and slight rises in CO2 partial pressure. The pH-temperature slope of both intra- and extracellular compartments varies considerably, from -0.009 to -0.033/degrees C, with a rather consistent pattern of red muscle greater than white muscle greater than heart. Three different approaches to acid-base analysis, the imidazole-alphastat model, the strong-ion difference analysis, and the delta-bicarbonate approach, were applied to a set of data from the fresh-water channel catfish (Ictalurus punctatus). A principal difficulty encountered in using all three approaches was that assumptions were required regarding the chemical behavior of the intracellular buffers, but the delta-bicarbonate approach has the practical advantage of emphasizing parameters that can be measured directly. Closed-system models are not generally applicable to fish, and the interest for future work lies in deciphering the significance of tissue-to-tissue variations in pH regulation and in elucidating the mechanisms of the strong-ion transfers.

Discordant Twins: Acid-Base Status

1991 ◽  
Vol 40 (3-4) ◽  
pp. 373-381 ◽  
Author(s):  
S.A. Ordorica ◽  
F.J. Frieden ◽  
I.A. Hoskins ◽  
B.K. Young
Keyword(s):  
Birth Weight ◽  
Acid Base ◽  
Apgar Scores ◽  
Twin Birth ◽  
Umbilical Blood ◽  
Base Parameters ◽  
Acid Base Status ◽  
Discordant Twins ◽  
A Prospective Study ◽  
Paired T Test

AbstractA prospective study was undertaken to determine the effect of twin birth-weight discordancy on Apgar scores and umbilical blood acid-base parameters. Using the paired t-test, small but statistically significant differences were seen in these parameters favoring the heavier twin over its lighter sibling. These differences were also affected by birth order, with the first-born being favored.

scholarly journals The importance of metabolism in acid–base regulation and acid–base methodology

1989 ◽  
Vol 67 (12) ◽  
pp. 3005-3017 ◽  
Author(s):  
Hans-Otto Pörtner
Keyword(s):  
Integrated Control ◽  
Feedback Regulation ◽  
Urea Synthesis ◽  
Acid Base ◽  
Base Parameters ◽  
Recent Developments ◽  
Acid Base Status ◽  
The Relationship ◽  
Aerobic And Anaerobic

Metabolism not only affects the acid–base status of an animal by means of proton stoichiometries but, by feedback regulation, acid–base parameters (pH, [Formula: see text], bicarbonate) influence metabolic rates and the pathways used. This leads to a significant contribution of metabolism to acid–base regulation under both aerobic and anaerobic conditions. The relationship between amino acid metabolism, urea synthesis, and [Formula: see text] excretion is discussed as an example important for steady-state metabolic acid–base regulation during aerobiosis. Generally, acid–base relevant metabolism may be regulated through the effect of acid–base disturbances on hormonal mediation, allosteric modulation of enzyme proteins, pH optima, and the levels of substrates or products, some of these being acid–base relevant substances like bicarbonate, CO2, inorganic phosphate, and NH3. During functional or environmental anaerobiosis the same relationships prevail. Metabolic proton accumulation is counterbalanced by phosphagen depletion and ammonia accumulation in adenylate catabolism. In addition, in integrated control of metabolic and acid–base status, long-term (mitochondrial) anaerobiosis leads to reductions in metabolic rate and increased removal of acidic groups. The importance of metabolic processes in acid–base methodology is discussed in terms of traditional concepts and recent developments.

The effects of hypercapnia on intracellular and extracellular acid-base status in the toad Bufo marinus

1982 ◽  
Vol 97 (1) ◽  
pp. 79-86
Author(s):  
D. P. Toews ◽  
N. Heisler
Keyword(s):  
Extracellular Space ◽  
Environmental Water ◽  
Bufo Marinus ◽  
Acid Base ◽  
Relative Preference ◽  
Base Parameters ◽  
Initial Drop ◽  
Acid Base Status ◽  
Body Compartments ◽  
Induced Changes

Toads (Bufo marinus) were exposed to environmental hypercapnia of 5% CO2 in air, and extracellular and intracellular acid-base parameters were determined 1 and 24 h after the onset of hypercapnia. The initial drop in pH was compensated by the elevation of extracellular and intracellular bicarbonate. Relating the pH compensation to the pH drop that is expected to occur by increased PCO2 at constant bicarbonate concentration, the pH compensation in the extracellular space was 30% and reached the following values for intracellular body compartments: 65% in skeletal muscle, 77% in heart muscle and 44% in skin. The additional bicarbonate was partly produced by blood and intracellular non-bicarbonate buffers; the major portion of the remainder was related to the excretion of ammonia into the environmental water. The hypercapnia-induced changes of pH were considerably smaller in all tissue cells than in the extracellular space. Thus Bufo marinus exhibits the relative preference of intracellular over extracellular acid-base regulation that has been observed in other vertebrates.

scholarly journals Recovery from Anaerobiosis in the Intertidal Worm Sipunculus Nudus: II. Gas Exchange and Changes in the Intra- and Extracellular Acid-Base Status

1986 ◽  
Vol 122 (1) ◽  
pp. 51-64
Author(s):  
H. O. PÖRTNER ◽  
S. VOGELER ◽  
M. K. GRIESHABER
Keyword(s):  
Gas Exchange ◽  
Metabolic Rate ◽  
Time Course ◽  
The Body ◽  
Coelomic Fluid ◽  
Acid Base ◽  
Extracellular Acidosis ◽  
Sipunculus Nudus ◽  
Acid Base Status ◽  
Negative Base

Intra- and extracellular acid-base status and changes of coelomic PCOCO2 were investigated during recovery following 24 h of anaerobiosis in Sipunculus nudus L. Metabolism, gas exchange and acid-base status were compared in animals collected during March and October. Anaerobiosis led to an uncompensated metabolic acidosis, the degree of the acidosis depending on the metabolic rate of the animals. During initial recovery in March animals, the acidosis was transiently aggravated in the extracellular, but not in the intracellular, compartment, indicating an efficient regulation of intracellular pH as soon as oxygen was available in the coelomic fluid. The extracellular acidosis was predominantly of non-respiratory origin. The non-respiratory part of the acidosis is attributed to the repletion of the phospho-l-arginine pool. The proton yield calculated from phosphagen resynthesis was highly correlated in time and in quantity to the observed negative base excess in the extracellular compartment. In October animals, strombine accumulation may have contributed to the acidosis that develops during recovery. The amount of succinate, propionate, and acetate in the coelomic plasma had already decreased when the acidosis developed. This discrepancy supports the conclusion that protons move between the body compartments independent of the distribution of anionic metabolites. The respiratory part of the acidosis is attributed to the repayment of an oxygen debt. The increase of PCOCO2 is higher in October than in March animals, probably because of differences in metabolic rate The time course of acid-base disturbances and their compensation is discussed in relation to the time course of metabolic events during recovery and to the priorities of the different processes observed.

scholarly journals Acid-base regulation, metabolism and energetics in sipunculus nudus as a function of ambient carbon dioxide level

1998 ◽  
Vol 201 (1) ◽  
pp. 43-55 ◽  
Author(s):  
H O Pörtner ◽  
A Reipschläger ◽  
N Heisler
Keyword(s):  
Ammonium Excretion ◽  
Ion Transfer ◽  
Energy Status ◽  
Intracellular Acidosis ◽  
Acid Base ◽  
Sipunculus Nudus ◽  
Acid Base Status ◽  
Net Release

Changes in the rates of oxygen consumption and ammonium excretion, in intra- and extracellular acid-base status and in the rate of H+-equivalent ion transfer between animals and ambient water were measured during environmental hypercapnia in the peanut worm Sipunculus nudus. During exposure to 1 % CO2 in air, intracellular and coelomic plasma PCO2 values rose to levels above those expected from the increase in ambient CO2 tension. Simultaneously, coelomic plasma PO2 was reduced below control values. The rise in PCO2 also induced a fall in intra- and extracellular pH, but intracellular pH was rapidly and completely restored. This was achieved during the early period of hypercapnia at the expense of a non-respiratory increase in the extracellular acidosis. The pH of the extracellular space was only partially compensated (by 37 %) during long-term hypercapnia. The net release of basic equivalents under control conditions turned to a net release of protons to the ambient water before a net, albeit reduced, rate of base release was re-established after a new steady state had been achieved with respect to acid-base parameters. Hypercapnia also affected the mode and rate of metabolism. It caused the rate of oxygen consumption to fall, whereas the rate of ammonium excretion remained constant or even increased, reflecting a reduction of the O/N ratio in both cases. The transient intracellular acidosis preceded a depletion of the phosphagen phospho-l-arginine, an accumulation of free ADP and a decrease in the level of Gibbs free energy change of ATP hydrolysis, before replenishment of phosphagen and restoration of pHi and energy status occurred in parallel. In conclusion, long-term hypercapnia in vivo causes metabolic depression, a parallel shift in acid-base status and increased gas partial pressure gradients, which are related to a reduction in ventilatory activity. The steady-state rise in H+-equivalent ion transfer to the environment reflects an increased rate of production of protons by metabolism. This observation and the reduction of the O/N ratio suggest that a shift to protein/amino acid catabolism has taken place. Metabolic depression prevails, with completely compensated intracellular acidosis during long-term hypercapnia eliminating intracellular pH as a significant factor in the regulation of metabolic rate in vivo. Fluctuating levels of the phosphagen, of free ADP and in the ATP free energy change values independent of pH are interpreted as being correlated with oscillating ATP turnover rates during early hypercapnia and as reflecting a tight coupling of ATP turnover and energy status via the level of free ADP.

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