The Time Course of Acid-Base Balance While on FBM Submarine Patrol

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.

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Regulatory processes of metabolic and respiratory acid-base disturbances in embryos

Journal of Applied Physiology ◽

10.1152/jappl.1982.53.6.1449 ◽

1982 ◽

Vol 53 (6) ◽

pp. 1449-1454 ◽

Cited By ~ 17

Author(s):

H. Tazawa

Keyword(s):

Renal Function ◽

Time Course ◽

Total Blood Volume ◽

Acid Base Balance ◽

Acid Base ◽

Total Blood ◽

Regulatory Processes ◽

Base Balance ◽

The Individual ◽

Control State

First, preliminary experiments were designed in the 16-day-old individual chick embryo to elucidate the effect of electrolyte infusion and blood samplings on hemodilution, which might influence the acid-base balance. Three kinds of hemodilution were observed: 1) hemodilution caused by four repetitive samplings, which had no influence on acid-base balance; 2) hypervolumic hemodilution caused by infusion of solution whose volume equaled about 5–6% of total blood volume, which induced dilution acidosis; and 3) hypertonic hemodilution caused by hypertonic electrolyte infusion, which also induced dilution acidosis. The embryo recovered from the hypertonic dilution acidosis in 6 h after infusion, but it did not recover from hypervolumic acidosis. Second, the time course of changes in metabolic and respiratory acid-base disturbances was studied in the individual embryo. Metabolic acid-base disturbances made by hypertonic NaHCO3 infusion were restored to control state in 6 h. Respiratory acid-base disturbances were also regulated in terms of changes in plasma[HCO-3] and pH. The renal function and redistribution of HCO-3 may in part be responsible for the regulation.

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Acid-base balance during repeated cycling sprints in boys and men

Journal of Applied Physiology ◽

10.1152/japplphysiol.00495.2001 ◽

2002 ◽

Vol 92 (2) ◽

pp. 479-485 ◽

Cited By ~ 56

Author(s):

S. Ratel ◽

P. Duche ◽

A. Hennegrave ◽

E. Van Praagh ◽

M. Bedu

Keyword(s):

Partial Pressure ◽

Time Course ◽

Base Excess ◽

Acid Base Balance ◽

Acid Base ◽

Arterial Partial Pressure ◽

Significant Relationships ◽

Base Balance ◽

Repeated Cycling ◽

Rest Intervals

The aim of this study was to investigate the acid-base balance during repeated cycling sprints in children and adults. Eleven boys (9.6 ± 0.7 yr) and ten men (20.4 ± 0.8 yr) performed ten 10-s sprints on a cycle ergometer separated by 30-s passive recovery intervals. To measure the time course of lactate ([La]), hydrogen ions ([H+]), bicarbonate ions ([HCO[Formula: see text]]), and base excess concentrations and the arterial partial pressure of CO2, capillary blood samples were collected at rest and after each sprint. Ventilation and CO2output were continuously measured. After the 10th sprint, concentrations of boys vs. men were as follows: [La], 8.5 ± 2.1 vs. 15.4 ± 2.0 mmol/l; [H+], 43.8 ± 1.3 vs. 66.9 ± 9.9 nmol/l ( P < 0.001). Significant correlations showed that, for a given [La], [H+] was lower in the boys compared with the men ( P < 0.001). Significant relationships also indicated that, for a given [La], [HCO[Formula: see text]] and base excess concentration were similar in the boys compared with the men. Moreover, significant relationships revealed that, for a given [H+] or [HCO[Formula: see text]], arterial partial pressure of CO2was lower in the boys compared with the men ( P < 0.001). The ventilation-to-CO2output ratio was higher in the boys during the first five rest intervals and was then higher in the men during the last five sprints. To conclude, during repeated sprints, the ventilatory regulation related to the change in acid-base balance induced by lactic acidosis was more important during the first rest intervals in the boys compared with the men.

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The acid-base balance during the time course of endotoxin fever and sodium salicylate antipyresis in the rabbit

Pharmacological Research Communications ◽

10.1016/0031-6989(86)90156-6 ◽

1986 ◽

Vol 18 (1) ◽

pp. 17-30

Author(s):

I.T. Gad ◽

E.E. Hac´

Keyword(s):

Time Course ◽

Sodium Salicylate ◽

Acid Base Balance ◽

Acid Base ◽

Base Balance

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Acid-base balance and blood and urine electrolytes of man during acclimatization to CO2

Journal of Applied Physiology ◽

10.1152/jappl.1964.19.1.48 ◽

1964 ◽

Vol 19 (1) ◽

pp. 48-58 ◽

Cited By ~ 17

Author(s):

K. E. Schaefer ◽

G. Nichols ◽

C. R. Carey

Keyword(s):

Cation Exchange ◽

Time Course ◽

Respiratory Acidosis ◽

Acid Base Balance ◽

Acid Base ◽

Low Concentration ◽

Base Balance ◽

Urine Electrolytes ◽

Two Phases ◽

Sodium And Potassium

Acid-base balance regulation and changes in electrolyte metabolism have been studied in 20 subjects exposed to 1.5% CO2 over a period of 42 days with control periods preceding and subsequent to exposure. During exposure to CO2 a slight uncompensated respiratory acidosis was present during the first 23 days followed by a compensated respiratory acidosis. Deacclimatization was incomplete, even after 4 weeks of recovery on air. Arterial CO2 tension increased 5 mm Hg during exposure and remained at this elevated level during the first 9 days of recovery on air. In chronic respiratory acidosis the concentration of chloride in the red cells and in plasma remains practically normal, indicating that the chloride shift does not operate. Cation exchange was observed under these conditions. Sodium increased while potassium showed an approximately equivalent decrease. Sodium and potassium balance studies indicated that only sodium exhibits a pattern paralleling the two phases of acid-base balance regulation, retention being followed by increased excretion. Body weight was maintained throughout the experiment in spite of a 24–30% reduction in food intake. mild respiratory acidosis and compensation; 1.5% CO2 exposure and recovery; arterial pCO2, chloride shift, and cation exchange; sodium and potassium excretion; sodium potassium and nitrogen balance; acid-base regulation in chronic hypercapnia; time course in acid-base regulations during chronic exposure to low concentration of CO2; acclimatization and deacclimatization to low concentration of CO2 Submitted on July 22, 1963

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Blood Acid-Base Balance in the Lugworm Arenicola Marina Ventilating in Hypo- or Hyperoxic Sea Water

Journal of Experimental Biology ◽

10.1242/jeb.142.1.143 ◽

1989 ◽

Vol 142 (1) ◽

pp. 143-153

Author(s):

ANDRÉ TOULMOND ◽

CATHERINE TCHERNIGOVTZEFF

Keyword(s):

Time Course ◽

Sea Water ◽

Acid Base Balance ◽

Acid Base ◽

Arenicola Marina ◽

Base Balance

The time course of variation in blood acid-base balance was examined in lugworms, Arenicola marina (L.), experimentally acclimated for up to 72 h in hypoxic (PO2 = 80 mmHg) (1 mmHg = 133.3 Pa), normoxic (PO2 = 160 mmHg) or hyperoxic (PO2 = 500 mmHg) sea water. In hyperoxic animals, a blood acidosis is entirely compensated 12 h after the beginning of the acclimation. In hypoxic animals, a blood alkalosis develops very quickly, persists and increases, reaching a maximum 72h after the beginning of the acclimation. In both cases, variation in blood acid-base balance is mainly of respiratory origin. These data are consistent with previous results showing that the lugworm hypoventilates in hyperoxic sea water and hyperventilates in hypoxic sea water.

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Higher Dietary Acidity is Associated with Lower Bone Mineral Density in Postmenopausal Iranian Women, Independent of Dietary Calcium Intake

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000207 ◽

2014 ◽

Vol 84 (3-4) ◽

pp. 0206-0217 ◽

Cited By ~ 8

Author(s):

Seyedeh-Elaheh Shariati-Bafghi ◽

Elaheh Nosrat-Mirshekarlou ◽

Mohsen Karamati ◽

Bahram Rashidkhani

Keyword(s):

Calcium Intake ◽

Dietary Calcium ◽

Dietary Calcium Intake ◽

Dietary Intakes ◽

Iranian Women ◽

Acid Base Balance ◽

Mineral Density ◽

Acid Base ◽

Base Balance ◽

Dietary Acid

Findings of studies on the link between dietary acid-base balance and bone mass are relatively mixed. We examined the association between dietary acid-base balance and bone mineral density (BMD) in a sample of Iranian women, hypothesizing that a higher dietary acidity would be inversely associated with BMD, even when dietary calcium intake is adequate. In this cross-sectional study, lumbar spine and femoral neck BMDs of 151 postmenopausal women aged 50 - 85 years were measured using dual-energy x-ray absorptiometry. Dietary intakes were assessed using a validated food frequency questionnaire. Renal net acid excretion (RNAE), an estimate of acid-base balance, was then calculated indirectly from the diet using the formulae of Remer (based on dietary intakes of protein, phosphorus, potassium, and magnesium; RNAERemer) and Frassetto (based on dietary intakes of protein and potassium; RNAEFrassetto), and was energy adjusted by the residual method. After adjusting for potential confounders, multivariable adjusted means of the lumbar spine BMD of women in the highest tertiles of RNAERemer and RNAEFrassetto were significantly lower than those in the lowest tertiles (for RNAERemer: mean difference -0.084 g/cm2; P=0.007 and for RNAEFrassetto: mean difference - 0.088 g/cm2; P=0.004). Similar results were observed in a subgroup analysis of subjects with dietary calcium intake of >800 mg/day. In conclusion, a higher RNAE (i. e. more dietary acidity), which is associated with greater intake of acid-generating foods and lower intake of alkali-generating foods, may be involved in deteriorating the bone health of postmenopausal Iranian women, even in the context of adequate dietary calcium intake.

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