Regulation of Hydrogen Ion Concentration (Acid–Base Balance)

2009 ◽  
pp. 325-335
Author(s):  
MH Dominiczak ◽  
M Szczepanska-Konkel
Keyword(s):  
Hydrogen Ion ◽  
Ion Concentration ◽  
Acid Base Balance ◽  
Acid Base ◽  
Hydrogen Ion Concentration ◽  
Base Balance

Role of peripheral chemoreceptors and central chemosensitivity in the regulation of respiration and circulation.

1982 ◽  
Vol 100 (1) ◽  
pp. 23-40 ◽  
Author(s):  
R G O'Regan ◽  
S Majcherczyk
Keyword(s):  
The Body ◽  
Ion Concentration ◽  
Regulation Of Respiration ◽  
Acid Base Balance ◽  
Acid Base ◽  
Vascular Effects ◽  
Peripheral Chemoreceptor ◽  
Hydrogen Ion Concentration ◽  
Central Chemosensitivity ◽  
Base Balance

Adjustments of respiration and circulation in response to alterations in the levels of oxygen, carbon dioxide and hydrogen ions in the body fluids are mediated by two distinct chemoreceptive elements, situated peripherally and centrally. The peripheral arterial chemoreceptors, located in the carotid and aortic bodies, are supplied with sensory fibres coursing in the sinus and aortic nerves, and also receive sympathetic and parasympathetic motor innervations. The carotid receptors, and some aortic receptors, are essential for the immediate ventilatory and arterial pressure increases during acute hypoxic hypoxaemia, and also make an important contribution to respiratory compensation for acute disturbances of acid-base balance. The vascular effects of peripheral chemoreceptor stimulation include coronary vasodilation and vasoconstriction in skeletal muscle and the splanchnic area. The bradycardia and peripheral vasoconstriction during carotid chemoreceptor stimulation can be lessened or reversed by effects arising from a concurrent hyperpnoea. Central chemoreceptive elements respond to changes in the hydrogen ion concentration in the interstitial fluid in the brain, and are chiefly responsible for ventilatory and circulatory adjustments during hypercapnia and chronic disturbances of acid-base balance. The proposal that the neurones responsible for central chemoreception are located superficially in the ventrolateral portion of the medulla oblongata is not universally accepted, mainly because of a lack of convincing morphological and electrophysiological evidence. Central chemosensitive structures can modify peripheral chemoreceptor responses by altering discharges in parasympathetic and sympathetic nerves supplying these receptors, and such modifications could be a factor contributing to ventilatory unresponsiveness in mild hypoxia. Conversely, peripheral chemoreceptor drive can modulate central chemosensitivity during hypercapnia.

Disorders of acid–base balance

2018 ◽  
Author(s):  
Aron Chakera ◽  
William G. Herrington ◽  
Christopher A. O’Callaghan
Keyword(s):  
The Body ◽  
Ion Concentration ◽  
Acid Base Balance ◽  
Acid Base ◽  
Compensatory Mechanisms ◽  
Urine Ph ◽  
Hydrogen Ion Concentration ◽  
Normal Metabolism ◽  
Base Balance ◽  
Ph Scale

Normal metabolism results in a net acid production of approximately 1 mmol/kg day−1. Physiological pH is regulated by excretion of this acid load (as carbon dioxide) by the kidneys and the lungs. A series of buffers in the body reduces the effects of metabolic acids on body and urine pH. For acid–base disorders to occur, there must be excessive intake (or loss) of acid (or base) or, alternatively, an inability to excrete acid. For these changes to result in a substantially abnormal pH, the various buffer systems must been overwhelmed. The pH scale is logarithmic, so relatively small changes in pH signify large differences in hydrogen ion concentration. Most minor perturbations in acid–base balance are asymptomatic, as small changes in acid or base levels are rapidly controlled through consumption of buffers or through changes in respiratory rate. Alterations in renal acid excretion take some time to occur. Only when these compensatory mechanisms are overwhelmed do symptoms related to changes in pH develop. This chapter reviews the causes and consequences of acid–base disorders.

Physicochemical analysis of phasic menstrual cycle effects on acid-base balance

2001 ◽  
Vol 280 (2) ◽  
pp. R481-R487 ◽  
Author(s):  
Robert J. Preston ◽  
Aaron P. Heenan ◽  
Larry A. Wolfe
Keyword(s):  
Menstrual Cycle ◽  
Ventilatory Threshold ◽  
Physicochemical Analysis ◽  
Carbon Dioxide Tension ◽  
Weak Acid ◽  
Ion Concentration ◽  
Strong Ion Difference ◽  
Acid Base Balance ◽  
Hydrogen Ion Concentration ◽  
Base Balance

In accordance with Stewart's physicochemical approach, the three independent determinants of plasma hydrogen ion concentration ([H+]) were measured at rest and during exercise in the follicular (FP) and luteal phase (LP) of the human menstrual cycle. Healthy, physically active women with similar physical characteristics were tested during either the FP ( n = 14) or LP ( n = 14). Arterialized blood samples were obtained at rest and after 5 min of upright cycling at both 70 and 110% of the ventilatory threshold (TVent). Measurements included plasma [H+], arterial carbon dioxide tension (PaCO2 ), total weak acid ([ATot]) as reflected by total protein, and the strong-ion difference ([SID]). The transition from rest to exercise in both groups resulted in a significant increase in [H+] at 70% TVentversus rest and at 110% TVent versus both rest and 70% TVent. No significant between-group differences were observed for [H+] at rest or in response to exercise. At rest in the LP, [ATot] and PaCO2 were significantly lower (acts to decrease [H+]) compared with the FP. This effect was offset by a reduction in [SID] (acts to increase [H+]). After the transition from rest to exercise, significantly lower [ATot] during the LP was again observed. Although the [SID] and PaCO2 were not significantly different between groups, trends for changes in these two variables were similar to changes in the resting state. In conclusion, mechanisms regulating [H+] exhibit phase-related differences to ensure [H+] is relatively constant regardless of progesterone-mediated ventilatory changes during the LP.

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.

scholarly journals Effect of Simulated Matches on Post-Exercise Biochemical Parameters in Women’s Indoor and Beach Handball

2020 ◽  
Vol 17 (14) ◽  
pp. 5046
Author(s):  
Joanna Kamińska ◽  
Tomasz Podgórski ◽  
Jakub Kryściak ◽  
Maciej Pawlak
Keyword(s):  
Blood Parameters ◽  
Ion Concentration ◽  
Electrolyte Balance ◽  
Acid Base Balance ◽  
Acid Base ◽  
Urine Ph ◽  
Physically Active ◽  
Post Exercise ◽  
Before And After ◽  
Base Balance

This study assesses the status of hydration and the acid-base balance in female handball players in the Polish Second League before and after simulated matches in both indoor (hall) and beach (outdoor) conditions. The values of biochemical indicators useful for describing water-electrolyte management, such as osmolality, hematocrit, aldosterone, sodium, potassium, calcium, chloride and magnesium, were determined in the players’ fingertip capillary blood. Furthermore, the blood parameters of the acid-base balance were analysed, including pH, standard base excess, lactate and bicarbonate ion concentration. Additionally, the pH and specific gravity of the players’ urine were determined. The level of significance was set at p < 0.05. It was found that both indoor and beach simulated matches caused post-exercise changes in the biochemical profiles of the players’ blood and urine in terms of water-electrolyte and acid-base balance. Interestingly, the location of a simulated match (indoors vs. beach) had a statistically significant effect on only two of the parameters measured post-exercise: concentration of calcium ions (lower indoors) and urine pH (lower on the beach). A single simulated game, regardless of its location, directly affected the acid-base balance and, to a smaller extent, the water-electrolyte balance, depending mostly on the time spent physically active during the match.

Changes in blood gases and acid-base balance in the exercising dog

1962 ◽  
Vol 17 (4) ◽  
pp. 656-660 ◽  
Author(s):  
Ronald L. Wathen ◽  
Howard H. Rostorfer ◽  
Sid Robinson ◽  
Jerry L. Newton ◽  
Michael D. Bailie
Keyword(s):  
Venous Blood ◽  
Blood Gases ◽  
Respiratory Alkalosis ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Mixed Venous Blood ◽  
Acid Base Balance ◽  
Hydrogen Ion Concentration ◽  
Arterial Blood ◽  
Mixed Venous

Effects of varying rates of treadmill work on blood gases and hydrogen ion concentrations of four healthy young dogs were determined by analyses of blood for O2 and CO2 contents, Po2, Pco2, and pH. Changes in these parameters were also observed during 30-min recovery periods from hard work. Arterial and mixed venous blood samples were obtained simultaneously during work through a polyethylene catheter in the right ventricle and an indwelling needle in an exteriorized carotid artery. Mixed venous O2 content, Po2 and O2 saturation fell with increased work, whereas arterial values showed little or no change. Mixed venous CO2 content, Pco2, and hydrogen ion concentration exhibited little change from resting levels in two dogs but increased significantly in two others during exercise. These values always decreased in the arterial blood during exercise, indicating the presence of respiratory alkalosis. On cessation of exercise, hyperventilation increased the degree of respiratory alkalosis, causing it to be reflected on the venous side of the circulation. Submitted on January 8, 1962

A physiological approach to acid–base disorders: The roles of ion transport and body fluid compartments

2020 ◽  
pp. 2182-2198
Author(s):  
Julian Seifter
Keyword(s):  
Metabolic Acidosis ◽  
Gas Analysis ◽  
Hydrogen Ion ◽  
Anion Gap ◽  
Ion Concentration ◽  
Hydrogen Ions ◽  
Acid Base ◽  
Hydrogen Ion Concentration ◽  
Arterial Blood Gas ◽  
Fluid Compartments

The normal pH of human extracellular fluid is maintained within the range of 7.35 to 7.45. The four main types of acid–base disorders can be defined by the relationship between the three variables, pH, Pco2, and HCO3 –. Respiratory disturbances begin with an increase or decrease in pulmonary carbon dioxide clearance which—through a shift in the equilibrium between CO2, H2O, and HCO3 –—favours a decreased hydrogen ion concentration (respiratory alkalosis) or an increased hydrogen ion concentration (respiratory acidosis) respectively. Metabolic acidosis may result when hydrogen ions are added with a nonbicarbonate anion, A−, in the form of HA, in which case bicarbonate is consumed, or when bicarbonate is removed as the sodium or potassium salt, increasing hydrogen ion concentration. Metabolic alkalosis is caused by removal of hydrogen ions or addition of bicarbonate. Laboratory tests usually performed in pursuit of diagnosis, aside from arterial blood gas analysis, include a basic metabolic profile with electrolytes (sodium, potassium, chloride, bicarbonate), blood urea nitrogen, and creatinine. Calculation of the serum anion gap, which is determined by subtracting the sum of chloride and bicarbonate from the serum sodium concentration, is useful. The normal value is 10 to 12 mEq/litre. An elevated value is diagnostic of metabolic acidosis, helpful in the differential diagnosis of the specific metabolic acidosis, and useful in determining the presence of a mixed metabolic disturbance. Acid–base disorders can be associated with (1) transport processes across epithelial cells lining transcellular spaces in the kidney, gastrointestinal tract, and skin; (2) transport of acid anions from intracellular to extracellular spaces—anion gap acidosis; and (3) intake.

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