scholarly journals Arteriovenous differences for amino acids and lactate across kidneys of normal and acidotic rats

1976 ◽  
Vol 160 (1) ◽  
pp. 125-128 ◽  
Author(s):  
E J Squires ◽  
D E Hall ◽  
J T Brosnan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Blood Lactate ◽  
Blood Concentration ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Arterial Blood

1. Arteriovenous differences fro amino acids across kidneys of normal and chronically acidotic rats were measured. Glutamine was the only amino acid extracted in increased amounts in acidosis. There was a considerable production of serine by kidneys from both normal and acidotic rats. 2. The arterial blood concentration of glutamine was significantly decreased in acidotic animals. 3. The glutamine extracted by kidneys of acidotic rats was largely and probably exclusively derived from the plasma. 4. The blood lactate concentration was unchanged in acidosis, as was the uptake of lactate by the kidney.

Lactic acid infusion in dogs: effects of varying infusate pH

1983 ◽  
Vol 54 (5) ◽  
pp. 1254-1260 ◽  
Author(s):  
L. B. Gladden ◽  
J. W. Yates
Keyword(s):  
Lactic Acid ◽  
Blood Lactate ◽  
Muscle Blood Flow ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Weak Acid ◽  
Muscle Lactate ◽  
Acid Infusion ◽  
Arterial Blood ◽  
Arterial Ph

This study had two purposes: 1) to determine the effects of varying the pH of lactic acid infusion solutions on the acid-base status of anesthetized dogs, and 2) to determine the effect of elevated blood lactate concentration on muscle lactate concentration. The experiments were performed on the in situ gastro cnemius-plantaris muscle group in 14 mongrel dogs. The infusions increased the arterial blood lactate concentration to 11.0 +/- 0.5 (SE) mM after 20 min. Above an infusate pH of 4.4, the arterial pH increased by 0.118–0.167 during infusion; the arterial pH was unchanged when the infusate pH was between 3.4 and 4.0; and the arterial pH decreased as infusate pH decreased below 3.0. The effect of lactic acid infusion on blood pH appears to be the result of two opposing effects: 1) an acidifying effect due to its weak acid properties, and 2) an alkalinizing effect due to the metabolism of sodium lactate. The estimated ratio between intracellular muscle lactate and venous plasma water lactate averaged 0.647 +/- 0.038, indicative of a substantial gradient between blood and muscle. The infusion produced a significant change from lactate output to lactate uptake by the muscles. The infusion also transiently increased muscle blood flow and oxygen uptake.

Effect of the blood lactate concentration on renal glutamine metabolism in dogs with chronic metabolic acidosis

1985 ◽  
Vol 63 (12) ◽  
pp. 1570-1576
Author(s):  
Mitchell L. Halperin ◽  
Ching B. Chen ◽  
Surinder Cheema-Dhadli
Keyword(s):  
Metabolic Acidosis ◽  
Blood Lactate ◽  
Filtration Rate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Glutamine Metabolism ◽  
Chronic Metabolic Acidosis ◽  
Arterial Blood ◽  
Constant Rate ◽  
Ammonium Metabolism

It appears that glutamine and lactate are the principal substrates for the kidney in dogs with chronic metabolic acidosis. Accordingly, the purpose of this study was to determine if a higher or lower rate of renal lactate extraction would influence the rate of glutamine extraction at a constant rate of renal ATP turnover. The blood lactate concentration was 0.9 ± 0.01 mM in 15 acidotic dogs. However, eight dogs with chronic metabolic acidosis had a spontaneous blood lactate concentration of 0.5 mM or lower. The kidneys of these dogs extracted considerably less lactate from the arterial blood (19 vs. 62 μmol/100 mL glomerular filtration rate (GFR)). Nevertheless, glutamine, alanine, citrate, and ammonium metabolism were not significantly different in these two groups of dogs. Renal ATP balance in acidotic dogs with a low blood lactate could only be achieved if a substrate other than additional glutamine were oxidized in that segment of the nephron which normally oxidized lactate; presumably a fat-derived substrate and (or) lactate derived from glucose was now the metabolic fuel at these more distal sites. When the blood lactate concentration was greater than 1.9 mM, lactate extraction rose to 219 μmol/100 mL GFR. Glutamine, alanine, citrate, and ammonium metabolism were again unchanged; in this case, ATP balance required substrate flux to products other than carbon dioxide, presumably, gluconeogenesis. It appears that renal ammoniagenesis is a proximal event and is independent of the rate of renal lactate extraction.

scholarly journals Evaluation of a Lactate Sensor for Rapid Repeated Measurements of Blood Lactate Concentration

1998 ◽  
Vol 26 (2) ◽  
pp. 184-188 ◽  
Author(s):  
J. V. Divatia ◽  
T. Jacques ◽  
P. Day ◽  
D. J. Bihari
Keyword(s):  
Blood Lactate ◽  
Coefficient Of Variation ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Laboratory Method ◽  
Repeated Measurements ◽  
Arterial Blood ◽  
Lactate Levels ◽  
Lactate Sensor ◽  
Serial Measurements

In critically ill patients, serial measurements of blood lactate may indicate adequacy of therapy and predict development of multi-organ failure. We studied the accuracy, precision, and repeatability of the newly developed 800 Series Lactate Sensor (Ciba Corning Diagnostic Corp., Medfield, U.S.A.). Lactate levels determined with the sensor were compared with the standard laboratory method (Abbott TDX) in 75 paired arterial blood samples from 20 patients. Agreement between methods was determined and the mean coefficient of variation calculated for repeated measurements. The bias of the sensor was -0.38 mmol/l (CI -0.23 to -0.53), and the precision ±0.67. The coefficient of variation for repeated measurements was 1.95% with the sensor, and 11.5% with the TDX (P=0.007). The new sensor offers a more reproducible, rapid method of measuring lactate, vital for serial measurements. The relatively wide limits of agreement between the methods reflect the greater variability of the TDX assay.

scholarly journals Lactate Arterial-Central Venous Gradient among COVID-19 Patients in ICU: A Potential Tool in the Clinical Practice

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Giuseppe Nardi ◽  
Gianfranco Sanson ◽  
Lucia Tassinari ◽  
Giovanna Guiotto ◽  
Antonella Potalivo ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Venous Blood ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Mitochondrial Metabolism ◽  
Lung Cells ◽  
Central Venous ◽  
Central Venous Blood ◽  
Arterial Blood ◽  
Anti Inflammatory

Objective. In physiological conditions, arterial blood lactate concentration is equal to or lower than central venous blood lactate concentration. A reversal in this rate (i.e., higher lactate concentration in central venous blood), which could reflect a derangement in the mitochondrial metabolism of lung cells induced by inflammation, has been previously reported in patients with ARDS but has been never explored in COVID-19 patients. The aim of this study was to explore if the COVID-19-induced lung cell damage was mirrored by an arterial lactatemia higher than the central venous one; then if the administration of anti-inflammatory therapy (i.e., canakinumab 300 mg subcutaneous) could normalize such abnormal lactate a-cv difference. Methods. A prospective cohort study was conducted, started on March 25, 2020, for a duration of 10 days, enrolling 21 patients affected by severe COVID-19 pneumonia undergoing mechanical ventilation consecutively admitted to the ICU of the Rimini Hospital, Italy. Arterial and central venous blood samples were contemporarily collected to calculate the difference between arterial and central venous lactate (Delta a-cv lactate) concentrations within 24 h from tracheal intubation (T0) and 24 hours after canakinumab administration (T1). Results. At T0, 19 of 21 (90.5%) patients showed a pathologic Delta a-cv lactate (median 0.15 mmol/L; IQR 0.07–0.25). In the 13 patients undergoing canakinumab administration, at T1, Delta a-cv lactate decreased in 92.3% of cases, the decrease being statistically significant (T0: median 0.24, IQR 0.09–0.31 mmol/L; T1: median −0.01, IQR −0.08–0.04 mmol/L; p=0.002). Conclusion. A reversed Delta a-cv lactate might be interpreted as one of the effects of COVID-19-related cytokine storm, which could reflect a derangement in the mitochondrial metabolism of lung cells induced by severe inflammation or other uncoupling mediators. In addition, Delta a-cv lactate decrease might also reflect the anti-inflammatory activity of canakinumab. Our preliminary findings need to be confirmed by larger outcome studies.

Changes in Acid-Base Balance during Peritoneal Dialysis with Fluid Containing Lactate Ions

1970 ◽  
Vol 39 (1) ◽  
pp. 51-60 ◽  
Author(s):  
S. R. Dixon ◽  
W. I. McKean ◽  
J. E. Pryor ◽  
R. O. H. Irvine
Keyword(s):  
Renal Failure ◽  
Peritoneal Dialysis ◽  
Metabolic Acidosis ◽  
Blood Lactate ◽  
Peritoneal Cavity ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Bicarbonate Concentration ◽  
Bicarbonate Ions ◽  
Arterial Blood

1. Twenty-three peritoneal dialyses with fluid containing 45 mEq lactate per litre were carried out on six patients with acute or chronic renal failure. During dialysis arterial blood pH and base excess rose. 2. The lactate ions were rapidly and almost completely absorbed from the fluid in the peritoneal cavity. Blood lactate concentration rose, but in patients with adequate liver function it did not exceed the normal range. One patient with poor hepatic function and renal failure showed abnormally high blood lactate levels after peritoneal dialysis, but metabolic acidosis was still corrected. 3. The concentration of bicarbonate ions in the fluid drained from the peritoneal cavity rose as the dialysis progressed. A significant positive correlation was found between the arterial blood bicarbonate concentration and the bicarbonate concentration in the fluid drained from the peritoneal cavity. 4. If the lactate ions absorbed from the peritoneal cavity had not been metabolized the loss of bicarbonate ions in the fluid drained from the peritoneal cavity would have increased the metabolic acidosis.

scholarly journals Comparison of Physiological and Perceptual Responses Between Continuous and Intermittent Cycling

2011 ◽  
Vol 29A (Special-Issue) ◽  
pp. 59-68 ◽  
Author(s):  
Roxana Brasil ◽  
Ana Barreto ◽  
Leandro Nogueira ◽  
Edil Santos ◽  
Jefferson Novaes ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Lactate ◽  
Arterial Blood Pressure ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Double Product ◽  
Arterial Blood ◽  
Rate Of Perceived Exertion

Comparison of Physiological and Perceptual Responses Between Continuous and Intermittent CyclingThe present study tested the hypothesis that the exercise protocol (continuous vs. intermittent) would affect the physiological response and the perception of effort during aquatic cycling. Each protocol was divided on four stages. Heart rate, arterial blood pressure, blood lactate concentration, central and peripheral rate of perceived exertion were collected in both protocols in aquatic cycling in 10 women (values are mean ± SD): age=32.8 ± 4.8 years; height=1.62 ± 0.05 cm; body mass=61.60 ± 5.19 kg; estimated body fat=27.13 ± 4.92%. Protocols were compared through two way ANOVA with Scheffé's post-hoc test and the test of Mann- Whitney for rate of perceived exertion with α=0.05. No systematic and consistent differences in heart rate, arterial blood pressure, double product and blood lactate concentration were found between protocols. On the other hand, central rate of perceived exertion was significantly higher at stage four during continuous protocol compared with intermittent protocol (p=0.01), while the peripheral rate of perceived exertion presented higher values at stages three (p=0.02) and four (p=0.00) in the continuous protocol when compared to the results found in intermittent protocol. These findings suggest that although the aquatic cycling induces similar physiologic demands in both protocols, the rate of perceived exertion may vary according to the continuous vs. intermittent nature of the exercise.

Maximal lactic capacity at altitude: effect of bicarbonate loading

1993 ◽  
Vol 75 (3) ◽  
pp. 1070-1074 ◽  
Author(s):  
B. Kayser ◽  
G. Ferretti ◽  
B. Grassi ◽  
T. Binzoni ◽  
P. Cerretelli
Keyword(s):  
Sea Level ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Altitude Effect ◽  
Arterial Blood ◽  
Arterial Ph ◽  
Arterial Blood Lactate ◽  
Arterial Blood Lactate Concentration ◽  
Blood Lactate Accumulation

The aim of the present study was to test the hypothesis that the net maximal blood lactate accumulation ([La]max) during heavy exercise in lowlanders acclimatized to chronic hypoxia may be limited by the reduced bicarbonate stores. Six men [age 32 +/- 4 (SD) yr] performed supramaximal exercise until voluntary exhaustion at sea level (204 +/- 54 W) and after sojourning for 1 mo at 5,050 m (175 +/- 23 W), without (C) and with (B) oral sodium-bicarbonate loading (0.3 g/kg body wt). Exhaustion time, arterial blood lactate concentration, arterial pH (pHa), arterial PCO2, and intramuscular pH were measured at rest and after exercise. At sea level, exhaustion time increased from 6.5 +/- 2.8 min in C to 7.5 +/- 2.7 min in B (P < 0.05). At altitude, exhaustion times were similar to the sea level C values and the same in C and B. At sea level, resting pHa increased from 7.41 +/- 0.02 in C to 7.46 +/- 0.03 in B (P < 0.001); the corresponding values at altitude were 7.46 +/- 0.04 and 7.55 +/- 0.03 (P < 0.001). Postexercise pHa at sea level was 7.22 +/- 0.02 in C and 7.25 +/- 0.08 in B (NS). After exercise at altitude, pHa was 7.32 +/- 0.04 and 7.44 +/- 0.03 in C and B, respectively (P < 0.001). [La]max increased from 12.86 +/- 1.45 mM in C to 16.63 +/- 1.76 mM in B (P < 0.01) at sea level and from 6.85 +/- 1.40 mM in C to 7.95 +/- 1.74 mM in B (NS) at altitude.(ABSTRACT TRUNCATED AT 250 WORDS)

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