Bone and shell contribution to lactic acid buffering of submerged turtles Chrysemys picta bellii at 3°C

2000 ◽  
Vol 278 (6) ◽  
pp. R1564-R1571 ◽  
Author(s):  
Donald C. Jackson ◽  
Carlos E. Crocker ◽  
Gordon R. Ultsch
Keyword(s):  
Lactic Acid ◽  
Lactate Concentration ◽  
Plasma Lactate ◽  
Acid Base ◽  
Bone Ash ◽  
Chrysemys Picta Bellii ◽  
Bone Water ◽  
Plasma Lactate Concentration ◽  
Plasma Calcium Concentration ◽  
Acid Base Status

To evaluate shell and bone buffering of lactic acid during acidosis at 3°C, turtles were submerged in anoxic or aerated water and tested at intervals for blood acid-base status and plasma ions and for bone and shell percent water, percent ash, and concentrations of lactate, Ca2+, Mg2+, Pi, Na+, and K+. After 125 days, plasma lactate concentration rose from 1.6 ± 0.2 mM (mean ± SE) to 155.2 ± 10.8 mM in the anoxic group but only to 25.2 ± 6.4 mM in the aerated group. The acid-base state of the normoxic animals was stable after 25 days of submergence. Plasma calcium concentration ([Ca2+]) rose during anoxia from 3.2 ± 0.2 to 46.0 ± 0.6 mM and [Mg2+] from 2.7 ± 0.2 to 12.2 ± 0.6 mM. Both shell and bone accumulated lactate to concentrations of 135.6 ± 35.2 and 163.6 ± 5.1 mmol/kg wet wt, respectively, after 125 days anoxia. Shell and bone [Na+] both fell during anoxia but the fate of this Na+ is uncertain because plasma [Na+] also fell. No other shell ions changed significantly in concentration, although the concentrations of both bone calcium and bone potassium changed significantly. Control shell water (27.8 ± 0.6%) was less than bone water (33.6 ± 1.1%), but neither changed during submergence. Shell ash (44.7 ± 0.8%) remained unchanged, but bone ash (41.0 ± 1.0%) fell significantly. We conclude that bone, as well as shell, accumulate lactate when plasma lactate is elevated, and that both export sodium carbonate, as well as calcium and magnesium carbonates, to supplement ECF buffering.

scholarly journals Contribution of net ion transfer mechanisms to acid-base regulation after exhausting activity in the larger spotted dogfish (Scyliorhinus stellaris)

1983 ◽  
Vol 103 (1) ◽  
pp. 31-46 ◽  
Author(s):  
G. F. Holeton ◽  
N. Heisler
Keyword(s):  
Lactic Acid ◽  
Lactate Concentration ◽  
Distribution Patterns ◽  
Environmental Water ◽  
Anaerobic Exercise ◽  
Acid Base ◽  
Acid Processing ◽  
Acid Base Status ◽  
Time Courses ◽  
Net Transfer

Specimens of the larger spotted dogfish (Scyliorhinus stellaris) were electrically stimulated to exhaustion in a closed seawater recirculation system. The production of large quantities of lactic acid by anaerobic metabolism and the resultant efflux of the dissociation products, H+ and lactate, from the white musculature resulted in severe acid-base disturbances and in increases in plasma lactate concentration, the two effects having extremely different time courses. Plasma pH and bicarbonate were maximally depressed 15–30 min after exercise, whereas peak lactate concentrations of up to 30 mM were not attained before 4–8 h after exercise. The acid-base status were restored to normal 10–14 h after exercise, long before the aerobic processing of surplus lactic acid was complete 22–30 h after exercise. This behaviour can be explained on the basis of an interaction of transfer rates, buffer values and equilibria between intracellular and extracellular compartments with the transient net transfer of surplus H+ ions to the environmental water. About half of the original quantity of H+ was transferred net to the environment via the branchial epithelium during the first 8–10 h, and it was later taken up again at the rate of aerobic lactic acid processing in the metabolism of the fish, whereas a transfer of lactate was not observed at any time during the experiment. As a result, the distribution patterns of H+ and lactate differed from each other and varied with time elapsed after anaerobic exercise, leading to the apparent ‘H+ ion deficit’ which has been observed in the blood of several fish species during lactacidosis. Net transfer of H+ ions to the environment facilitates rapid normalization of the acid-base status long before the original stress, lactic acid, is removed from the organism and thus represents an effective regulatory mechanism for the defence of the internal milieu in fish.

Glucose and lactate kinetics after endotoxin administration in dogs.

1977 ◽  
Vol 232 (2) ◽  
pp. E180 ◽  
Author(s):  
R R Wolfe ◽  
D Elahi ◽  
J J Spitzer
Keyword(s):  
Lactate Concentration ◽  
Constant Infusion ◽  
Glucose Turnover ◽  
Metabolic Clearance ◽  
Plasma Lactate ◽  
Metabolic Clearance Rate ◽  
Metabolic Substrate ◽  
E Coli ◽  
Lactate Kinetics ◽  
Plasma Lactate Concentration

We studied the effects of E. coli endotoxin on the glucose and lactate kinetics in dogs by means of the primed constant infusion of [6(-3)H] glucose and Na-L-(+)-[U-14C] lactate. The infusion of endotoxin induced a transient hyperglycemic level, followed by a steady fall in plasma glucose to hypoglycemic levels. The rate of appearance (Ra) and the rate of disappearance (Rd) of glucose were both significantly elevated (P less than .05) for 150 min after endotoxin, after which neither differed from the preinfusion value. The metabolic clearance rate of glucose was significantly elevated at all times 30 min postendotoxin. By 30 min postendotoxin, Ra and Rd of lactate, plasma lactate concentration, and the percent of glucose turnover originating from lactate were significantly elevated and remained so for the duration of the experiment. We concluded that after endotoxin hypoglycemia developed because of an enhanced peripheral uptake of glucose and a failure of the liver to maintain an increased Ra of glucose. We also concluded that lactate became an important precursor for gluconeogenesis and an important metabolic substrate.

scholarly journals Effects of exercise on plasma lactic acid and body temperature in man, following a standardized meal

2018 ◽  
Vol 17 (2) ◽  
pp. 270-274
Author(s):  
Tesleem K Babalola ◽  
Udoh Utibe Abasi
Keyword(s):  
Lactic Acid ◽  
Body Temperature ◽  
Statistical Tests ◽  
Medical Science ◽  
Lactate Concentration ◽  
Bicycle Ergometer ◽  
Mean Value ◽  
Plasma Lactate ◽  
Post Exercise ◽  
Before And After

Background: The effects of exercise on plasma lactic acid level and body temperature following a standardized meal were carried out on 20 healthy young individuals (aged between 18 and 29 yrs.), consisting of 10 males and 10 females. The physical fitness of the subjects was determined measuring their blood pressure, pulse rate and other physical examinations.Methodology: Each subject was made to ride the bicycle ergometer for 6mins, at a rhythmic cadence of 50revolution/ min via 100beats metronome counts. Blood samples were collected before and after the exercise to analyze for the pre and post exercise plasma lactate levels. Pre and post-exercise values for body temperature were also measured. Statistical tests were carried out at 95% CI (P=0.05).Result: The result obtained showed that exercise causes a statistically significant increase (p< 0.05) in both plasma lactate concentration (from a pre-exercise mean value of 0.98 ±0.07mmol/L to post- exercise mean value of 2.84 ±0.21mmol/L) and body temperature (from a mean value of 36.45 ±0.130C before exercise to a mean value of 36.91 ±0.190C after exercise).Conclusion: There was a statistically significant increase in plasma lactateand body temperature because of exposure to exercise which is in line with findings from most previous studies.Bangladesh Journal of Medical Science Vol.17(2) 2018 p.270-274

Adrenergic blockade prevents endotoxin-induced increases in glucose metabolism

1988 ◽  
Vol 255 (5) ◽  
pp. E629-E635 ◽  
Author(s):  
D. M. Hargrove ◽  
G. J. Bagby ◽  
C. H. Lang ◽  
J. J. Spitzer
Keyword(s):  
Plasma Insulin ◽  
Lactate Concentration ◽  
Insulin Concentration ◽  
Adrenergic Blockade ◽  
Plasma Lactate ◽  
Glucose Kinetics ◽  
Plasma Insulin Concentration ◽  
Beta Adrenergic ◽  
Plasma Lactate Concentration ◽  
Adrenergic Antagonists

Combined alpha- and beta-adrenergic blockade was used to investigate the role of catecholamines in endotoxin-induced elevations in glucose kinetics. Glucose kinetics were measured before and for 4 h after the injection of endotoxin [100 micrograms/100 g body wt iv, 30% lethal dose (LD30) at 24 h]. Adrenergic blockade was achieved by the bolus injection of phentolamine and propranolol followed by their continuous infusion. Endotoxin-treated rats exhibited a transient hyperglycemia and sustained (greater than 4 h) increase in plasma lactate concentration, as well as elevated rates of glucose appearance (Ra, 83%), disappearance (Rd, 58%), recycling (160%), and metabolic clearance (23%). Adrenergic blockade prevented endotoxin-induced increases in plasma glucose concentration, Ra, Rd, and recycling but not glucose clearance. The increase in plasma lactate concentration was blunted by 35%. After 2 h, endotoxic animals infused with adrenergic antagonists developed hypoglycemia, which may have resulted from an increased plasma insulin concentration. The attenuation of elevated glucose turnover by adrenergic blockade in the endotoxin-treated animals was not due to a reduction in plasma glucagon level or differences in plasma insulin concentration. Administration of the alpha- or beta-adrenergic antagonists separately blunted but did not prevent endotoxin-induced changes in glucose kinetics, and therefore the efficacy of the adrenergic blockade could not be assigned to a single receptor class. These results indicate that catecholamines are important contributory factors to many of the early alterations in carbohydrate metabolism observed during endotoxemia.

Plasma lactate and ventilation thresholds in trained and untrained cyclists

1986 ◽  
Vol 60 (3) ◽  
pp. 777-781 ◽  
Author(s):  
J. Simon ◽  
J. L. Young ◽  
D. K. Blood ◽  
K. R. Segal ◽  
R. B. Case ◽  
...  
Keyword(s):  
Lactate Threshold ◽  
Minute Ventilation ◽  
Lactate Concentration ◽  
Work Rate ◽  
Plasma Lactate ◽  
Vo2 Max ◽  
Trained Subjects ◽  
Leg Cycling ◽  
Plasma Lactate Concentration ◽  
Removal Processes

Six trained male cyclists and six untrained sedentary men were studied to determine whether the plasma lactate threshold (PLT) and ventilation threshold (VT) occur at the same work rate in both fit and unfit populations. The PLT was determined from a marked increase in plasma lactate concentration ([La]) and VT from a nonlinear increase in expired minute ventilation (VE) during incremental leg-cycling tests; work rate was increased 30 W every 2 min until volitional exhaustion. The trained subjects' mean VO2 max (63.8 ml O2 X kg-1 X min-1) and VT (65.8% VO2 max) were significantly higher (P less than 0.05) than the untrained subjects' mean VO2max (35.5 ml O2 X kg-1 X min-1) and VT (51.4% VO2 max). The trained subjects' mean PLT (68.8% VO2 max) and VT did not differ significantly, but the untrained subjects' mean PLT (61.6% VO2 max) was significantly higher than their VT. The trained subjects' mean peak [La] (10.5 mmol X l-1) did not differ significantly from the untrained subjects' mean peak [La] (11.5 mmol X l-1). However, the time of appearance of the peak [La] during passive recovery was inversely related to VO2 max. These results suggest that variance in lactate diffusion and/or removal processes between the trained and untrained subjects may account in part for the different relationships between the VT and PLT in each population.

Diving and swimming performance of white whales, Delphinapterus leucas: an assessment of plasma lactate and blood gas levels and respiratory rates.

1997 ◽  
Vol 200 (24) ◽  
pp. 3091-3099 ◽  
Author(s):  
S A Shaffer ◽  
D P Costa ◽  
T M Williams ◽  
S H Ridgway
Keyword(s):  
High Speed ◽  
Swimming Performance ◽  
Lactate Concentration ◽  
Delphinapterus Leucas ◽  
Breath Hold ◽  
Plasma Lactate ◽  
Post Exercise ◽  
Test Platform ◽  
Plasma Lactate Concentration ◽  
Breath Hold Duration

The white whale Delphinapterus leucas is an exceptional diver, yet we know little about the physiology that enables this species to make prolonged dives. We studied trained white whales with the specific goal of assessing their diving and swimming performance. Two adult whales performed dives to a test platform suspended at depths of 5-300 m. Behavior was monitored for 457 dives with durations of 2.2-13.3 min. Descent rates were generally less than 2 m s-1 and ascent rates averaged 2.2-3 m s-1. Post-dive plasma lactate concentration increased to as much as 3.4 mmol l-1 (4-5 times the resting level) after dives of 11 min. Mixed venous PO2 measured during voluntary breath-holds decreased from 79 to 20 mmHg within 10 min; however, maximum breath-hold duration was 17 min. Swimming performance was examined by training the whales to follow a boat at speeds of 1.4-4.2 m s-1. Respiratory rates ranged from 1.6 breaths min-1 at rest to 5.5 breaths min-1 during exercise and decreased with increasing swim speed. Post-exercise plasma lactate level increased to 1.8 mmol l-1 (2-3 times the resting level) following 10 min exercise sessions at swimming speeds of 2.5-2.8 m s-1. The results of this study are consistent with the calculated aerobic dive limit (O2 store/metabolic rate) of 9-10 min. In addition, white whales are not well adapted for high-speed swimming compared with other small cetaceans.

The Effect of Long-Term Aerial Exposure on Heart Rate, Ventilation, Respiratory Gas Exchange and Acid-Base Status in the Crayfish Austropotamobius Pallipes

1981 ◽  
Vol 92 (1) ◽  
pp. 109-124
Author(s):  
E. W. TAYLOR ◽  
MICHÈLE G. WHEATLY
Keyword(s):  
Heart Rate ◽  
Lactic Acid ◽  
O2 Consumption ◽  
Aerial Exposure ◽  
Acid Base ◽  
Bicarbonate Buffer ◽  
Content Difference ◽  
Acid Base Status ◽  
Lactate Levels

1. When first removed into air, crayfish showed transient increases in heart rate (fH) and scaphognathite rate (fR) which rapidly recovered to submerged levels and were unchanged for 24 h. The rate of O2 consumption(Moo2) increased from an initially low level and was then maintained for 24 h in air at the same level as in settled submerged animals. 2. There was an initial acidosis in the haemolymph which was both respiratory and metabolic due to the accumulation of CO2 and lactate. Progressive compensation by elevation of the levels of bicarbonate buffer in the haemolymph and reduction of circulating lactate levels returned pH towards submerged levels after 24 h in air. 3. Exposure to air resulted in a marked internal hypoxia with haemolymph O2, tensions, both postbranchial Pa, oo2 and prebranchial Pv, oo2, remaining low throughout the period of exposure. The oxygen content or the haemolymph was initially reduced, with a - vOO2 content difference close to zero. Within 24 h both Ca, oo2 and Cv, OO2 had returned towards their levels in submerged animals. These changes are explained by the Bohr shift on the haemocyanin consequent upon the measured pH changes. 4. After 48 h in air, MO2 and fH were significantly reduced and ventilation became intermittent. There was a slight secondary acidosis, increase in lactic acid levels and reduction in a - vO2 content difference in the haemolymph. 5. When crayfish were returned to water after 24 h in air, MOO2, fHfR were initially elevated by disturbance and there was a period of hyperventilation. In the haemolymph there was an initial slight alkalosis, and an increase in Ca, OO2 lactic acid. All variables returned to their settled submerged levels within 8 h.

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.

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