pH regulation of endogenous acid production in subjects with chronic ketoacidosis

1985 ◽  
Vol 249 (2) ◽  
pp. F220-F226 ◽  
Author(s):  
V. L. Hood
Keyword(s):  
Organic Acid ◽  
Acid Production ◽  
Ph Regulation ◽  
Acid Output ◽  
Hydrogen Ion ◽  
Significant Modification ◽  
Acid Base Balance ◽  
Acid Base ◽  
Effective Mechanism ◽  
Base Balance

In a previous study of starvation-induced acute ketoacidosis, net ketoacid production was inhibited by acid and facilitated by base ingestion. To determine whether hydrogen ion modifies net ketoacid production during chronic ketoacidosis, six over-weight volunteers ingested NaHCO3, NaCl, or NH4Cl (2 mmol X kg-1 X day-1), each for 7 days, during weeks 6-8 of ketogenic dieting. During days 4-7 of each phase, blood bicarbonate was stable but lower in the NH4Cl (19.6 +/- 0.7 mM) than the NaHCO3 (23.7 +/- 0.7 mM) phases. Throughout these periods, acid intake differed by 216 mmol/day, whereas acid output differed by 129 mmol/day between the NaHCO3 and the NH4Cl phases. The major contribution to this difference in acid balance was a difference in net organic acid (ketoacid) production. Although blood ketones were stable, ketoacid excretion, reflecting net ketoacid production, was decreased by 59% with acid and increased by 66% with base compared with NaCl (control) ingestion. Thus, in this state of chronic ketoacidosis, challenges to acid-base balance were countered by a rapidly occurring, sustained, reversible, and quantitatively significant modification of net acid production which acted as an effective mechanism for acid-base regulation.

Impact of hydrogen ion on fasting ketogenesis: feedback regulation of acid production

1982 ◽  
Vol 242 (3) ◽  
pp. F238-F245 ◽  
Author(s):  
V. L. Hood ◽  
E. Danforth ◽  
E. S. Horton ◽  
R. L. Tannen
Keyword(s):  
Acid Production ◽  
Metabolic Regulation ◽  
Feedback Regulation ◽  
Hydrogen Ion ◽  
Acid Excretion ◽  
Acid Base Balance ◽  
Acid Base ◽  
Urine Ph ◽  
Ion Production ◽  
Base Balance

To determine whether acid-base balance regulates hydrogen ion production, seven obese volunteers were given NaHCO3 and NH4Cl (2 mmol.kg-1.day-1) during two separate 7-day fasts. On days 5-7 plasma bicarbonate was lower in the NH4Cl fasts (14.0 +/- 1.4 mM) than in the NaHCO3 fasts (18.3 +/- 1.1 mM), while urine pH and net acid excretion did not differ. Acid production (acid excretion minus intake) was greater by 204 mmol/day in the NaHCO3 fasts (274 +/- 16 mmol/day) than in the NH4Cl fasts (70 +/- 19 mmol/day). Ketoacid excretion, which reflected net ketoacid production, paralleled acid production, decreasing from 213 +/- 24 mmol/day in the NaHCO3 fasts to 67 +/- 18 mmol/day in the NH4Cl fasts. Thus, during starvation, alterations in hydrogen ion intake and the associated changes in acid-base balance modify the net production of endogenous acid by influencing the synthesis or utilization of ketoacids. Although the specific site of this metabolic regulation is undefined, these results indicate that systemic acid-base status can exert feedback control over hydrogen ion production.

Whole body acid-base modeling revisited

2017 ◽  
Vol 312 (4) ◽  
pp. F647-F653 ◽  
Author(s):  
Troels Ring ◽  
Søren Nielsen
Keyword(s):  
Acid Production ◽  
Negative Charge ◽  
Whole Body ◽  
Acid Excretion ◽  
Acid Base Balance ◽  
Acid Base ◽  
Conventional Model ◽  
Renal Net Acid Excretion ◽  
Base Balance ◽  
Alkali Absorption

The textbook account of whole body acid-base balance in terms of endogenous acid production, renal net acid excretion, and gastrointestinal alkali absorption, which is the only comprehensive model around, has never been applied in clinical practice or been formally validated. To improve understanding of acid-base modeling, we managed to write up this conventional model as an expression solely on urine chemistry. Renal net acid excretion and endogenous acid production were already formulated in terms of urine chemistry, and we could from the literature also see gastrointestinal alkali absorption in terms of urine excretions. With a few assumptions it was possible to see that this expression of net acid balance was arithmetically identical to minus urine charge, whereby under the development of acidosis, urine was predicted to acquire a net negative charge. The literature already mentions unexplained negative urine charges so we scrutinized a series of seminal papers and confirmed empirically the theoretical prediction that observed urine charge did acquire negative charge as acidosis developed. Hence, we can conclude that the conventional model is problematic since it predicts what is physiologically impossible. Therefore, we need a new model for whole body acid-base balance, which does not have impossible implications. Furthermore, new experimental studies are needed to account for charge imbalance in urine under development of acidosis.

scholarly journals Extracellular Acid-Base Balance and Ion Transport Between Body Fluid Compartments

Physiology ◽  
2017 ◽  
Vol 32 (5) ◽  
pp. 367-379 ◽  
Author(s):  
Julian L. Seifter ◽  
Hsin-Yun Chang
Keyword(s):  
Ion Transport ◽  
Ph Regulation ◽  
Extracellular Fluid ◽  
Transport Processes ◽  
Electrolyte Balance ◽  
Ph Homeostasis ◽  
Acid Base Balance ◽  
Acid Base ◽  
Base Balance ◽  
Fluid Compartments

Clinical assessment of acid-base disorders depends on measurements made in the blood, part of the extracellular compartment. Yet much of the metabolic importance of these disorders concerns intracellular events. Intracellular and interstitial compartment acid-base balance is complex and heterogeneous. This review considers the determinants of the extracellular fluid pH related to the ion transport processes at the interface of cells and the interstitial fluid, and between epithelial cells lining the transcellular contents of the gastrointestinal and urinary tracts that open to the external environment. The generation of acid-base disorders and the associated disruption of electrolyte balance are considered in the context of these membrane transporters. This review suggests a process of internal and external balance for pH regulation, similar to that of potassium. The role of secretory gastrointestinal epithelia and renal epithelia with respect to normal pH homeostasis and clinical disorders are considered. Electroneutrality of electrolytes in the ECF is discussed in the context of reciprocal changes in Cl−or non Cl−anions and [Formula: see text].

Acid-Base Balance with Different Capd Solutions

1996 ◽  
Vol 16 (1_suppl) ◽  
pp. 126-129 ◽  
Author(s):  
Mariano Feriani ◽  
Claudio Ronco ◽  
Giuseppe La Greca
Keyword(s):  
Acid Production ◽  
Dwell Time ◽  
Lactate Concentration ◽  
The Body ◽  
Plasma Lactate ◽  
Acid Base Balance ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Plasma Bicarbonate ◽  
Base Balance

Our objective is to investigate transperitoneal buffer fluxes with solution containing lactate and bicarbonate, and to compare the final effect on body base balance of the two solutions. One hundred and four exchanges, using different dwell times, were performed in 52 stable continuous ambulatory peritoneal dialysis (CAPD) patients. Dialysate effluent lactate and bicarbonate and volumes were measured. Net dialytic base gain was calculated. Patients’ acid-base status and plasma lactate were determined. In lactate-buffered CAPD solution, lactate concentration in dialysate effluent inversely correlated with length of dwell time, but did not correlate with plasma lactate concentration and net ultrafiltration. Bicarbonate concentration in dialysate effluent correlated with plasma bicarbonate and dwell time but not with ultrafiltration. The arithmetic sum of the lactate gain and bicarbonate loss yielded the net dialytic base gain. Ultrafiltration was the most important factor affecting net dialytic base gain. A previous study demonstrated that in patients using a bicarbonate-buffered solution the net bicarbonate gain is a function of dwell time, ultrafiltration, and plasma bicarbonate. By combining the predicted data of the dialytic base gain with the calculated metabolic acid production, an approximate body base balance could be obtained with both lactate and bicarbonate-buffered CAPD solutions. The body base balance in CAPD patients is self-regulated by the feedback between plasma bicarbonate concentration and dialytic base gain. The level of plasma bicarbonate is determined by the dialytic base gain and the metabolic acid production. This can explain the large interpatient variability in acid-base correction. Bicarbonate-buffered CAPD solution is equal to lactate solution in correcting acid-base disorders of CAPD patients.

scholarly journals Transport Metabolons and Acid/Base Balance in Tumor Cells

Cancers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 899 ◽  
Author(s):  
Holger M. Becker ◽  
Joachim W. Deitmer
Keyword(s):  
Cancer Cells ◽  
Tumor Cells ◽  
Drug Targets ◽  
Ph Regulation ◽  
Host Cells ◽  
Bicarbonate Transport ◽  
Carbonic Anhydrases ◽  
Acid Base Balance ◽  
Acid Base ◽  
Base Balance

Solid tumors are metabolically highly active tissues, which produce large amounts of acid. The acid/base balance in tumor cells is regulated by the concerted interplay between a variety of membrane transporters and carbonic anhydrases (CAs), which cooperate to produce an alkaline intracellular, and an acidic extracellular, environment, in which cancer cells can outcompete their adjacent host cells. Many acid/base transporters form a structural and functional complex with CAs, coined “transport metabolon”. Transport metabolons with bicarbonate transporters require the binding of CA to the transporter and CA enzymatic activity. In cancer cells, these bicarbonate transport metabolons have been attributed a role in pH regulation and cell migration. Another type of transport metabolon is formed between CAs and monocarboxylate transporters, which mediate proton-coupled lactate transport across the cell membrane. In this complex, CAs function as “proton antenna” for the transporter, which mediate the rapid exchange of protons between the transporter and the surroundings. These transport metabolons do not require CA catalytic activity, and support the rapid efflux of lactate and protons from hypoxic cancer cells to allow sustained glycolytic activity and cell proliferation. Due to their prominent role in tumor acid/base regulation and metabolism, transport metabolons might be promising drug targets for new approaches in cancer therapy.

scholarly journals Ventilation and acid-base balance during graded activity in lizards

1981 ◽  
Vol 240 (1) ◽  
pp. R29-R37 ◽  
Author(s):  
G. S. Mitchell ◽  
T. T. Gleeson ◽  
A. F. Bennett
Keyword(s):  
Treadmill Exercise ◽  
Control Level ◽  
Hydrogen Ion ◽  
Co2 Production ◽  
Acid Base Balance ◽  
Acid Base ◽  
Lizard Species ◽  
Arterial Pco2 ◽  
Base Balance ◽  
Graded Activity

Arterial PCO2, hydrogen ion ([H+]a), and lactate ([L]a) concentrations, rates of metabolic CO2 production (VCO2) and O2 consumption (VO2), and effective alveolar ventilation (Veff) were determined in the lizards Varanus exanthematicus and Iguana iguana at rest and during steady-state treadmill exercise at 35 degrees C. In Varanus, VCO2 increased ninefold and VO2 sixfold without detectable rise in [L]a at running speeds below 1.0 to 1.5 km x h-1. In this range, Veff increased 12-fold resulting in decreased levels of PaCO2 and [H+]a. At higher speeds [L]a rose. Increments of 5 mM [L]a were accompanied by hyperventilation, reducing PaCO2 and thus maintaining [H+]a near its resting level. When [L]a increased further, [H+]a increased. Sustainable running speeds (0.3-0.5 km x h-1 and below) were often associated with increased VO2, VCO2, and [L]a in Iguana. Sixfold increases in VCO2 and 9-mM increments in [L]a were accompanied by sufficient increase in Veff (9-fold) to maintain [H+]a at or below its control level. When [L]a increased further, [H+]a increased. These results indicate that both lizard species maintain blood acid-base homeostasis rather effectively via ventilatory adjustments at moderate exercise intensities.

scholarly journals The 100th anniversary of pH (1909-2009). Negative logarithms for measuring hydrogen ions: are they essential in medicine? Part I

2013 ◽  
pp. 147-155
Author(s):  
Francesco Sgambato ◽  
Sergio Prozzo ◽  
Ester Sgambato ◽  
Rosa Sgambato ◽  
Luca Milano
Keyword(s):  
Human Life ◽  
100Th Anniversary ◽  
Hydrogen Ion ◽  
Hydrogen Ions ◽  
Acid Base Balance ◽  
Acid Base ◽  
The Past ◽  
Scientific Papers ◽  
Base Balance ◽  
Ph Scale

Introduction: It has been 100 years since the concept of pH (1909-2009) was ‘‘invented’’ by the Danish chemist-mathematician Søren Peter Lauritz Sørensen (1868-1939) in the chemistry laboratories of the Carlsberg Brewery in Copenhagen. The anniversary provides an opportunity to examine the crucial importance in human life of acid-base balance. Materials and methods: The authors review the historical process that led to the creation of the pH scale, with citation of passages from the original work of Sørensen published 100 years ago. This is followed by a critical analysis of the debate regarding the use of logarithmstomeasure hydrogen ion concentrations based on data from scientific papers published over the past 50 years (1960-2010). Results and discussion: The authors conclude that the concept of acid-base balance can be approached and taught in a simpler, more exciting, and even pleasant fashion without using the infamous and abstruse Henderson-Hasselbalch equation. The whole rationale underlying the understanding and clinical application of this vital topic is clearly and unquestionably inherent simpler, more manageable formula introduced by Henderson (without logs), which is useful and quite adequate for use in medical education.

scholarly journals pH-regulation: the role of the hepatorenal system

1987 ◽  
Vol 6 (3) ◽  
pp. 115-117
Author(s):  
M. J. Pitout ◽  
G. T. Willemse
Keyword(s):  
Ph Regulation ◽  
Buffer System ◽  
Urea Synthesis ◽  
Ph Homeostasis ◽  
Acid Base Balance ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Base Balance ◽  
The Relationship

The regulation of the acid-base balance is generally regarded as a well entrenched area. However, a number of confusing views on pH-homeostasis, especially with reference to the relationship between the kidney and the ammonium buffer system, appear regularly in textbooks. One reason is that the correct stoichiometry of acid-base regulation is not mentioned. Recently the rote of the liver in pH regulation by controlling the bicarbonate concentration through urea synthesis is proposed. In this paper the role of the liver and kidneys as a team is discussed.

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