scholarly journals Metabolism and energetics in squid (Illex illecebrosus, Loligo pealei) during muscular fatigue and recovery

1993 ◽  
Vol 265 (1) ◽  
pp. R157-R165 ◽  
Author(s):  
H. O. Portner ◽  
D. M. Webber ◽  
R. K. O'Dor ◽  
R. G. Boutilier
Keyword(s):  
Energy Production ◽  
Detrimental Effect ◽  
Anaerobic Metabolism ◽  
Energy Status ◽  
Acid Base ◽  
Mantle Tissue ◽  
Anaerobic Energy ◽  
Acid Base Status ◽  
Postexercise Recovery ◽  
Loligo Pealei

The concentrations of intermediate and end products of anaerobic energy metabolism and of free amino acids were determined in mantle musculature and blood sampled from cannulated, unrestrained squid (Loligo pealei, Illex illecebrosus) under control conditions, after fatigue from increasing levels of exercise, and during postexercise recovery. Phosphagen depletion, accumulation of octopine (more so in Illex than in Loligo), and accumulation of succinate indicate that anaerobic metabolism contributes to energy production before fatigue. Proline was a substrate of metabolism in Loligo, as indicated by its depletion in the mantle. In both species, there was no evidence of catabolism of ATP beyond AMP. A comparison of the changes in the free and total levels of adenylates and the phosphagen indicates an earlier detrimental effect of fatigue on the energy status in Loligo. The acidosis provoked by octopine formation in Illex was demonstrated to promote the use of the phosphagen and to protect the free energy change of ATP such that the anaerobic scope of metabolism during swimming is extended and expressed more in Illex than in Loligo. In both species, there was no decrease in the sum of phospho-L-arginine, octopine, and L-arginine, and thus no release of octopine from the mantle, thereby supporting our earlier claim that octopine and associated protons are recycled in the mantle tissue. Overall, the metabolic strategy of Loligo is much less disturbing for the acid-base status. This strategy and the alternative strategy of Illex to keep acidifying protons in the tissue may be important for the protection of hemocyanin function in the two species.

scholarly journals Acid-base regulation in exercising squid (Illex illecebrosus, Loligo pealei)

1991 ◽  
Vol 261 (1) ◽  
pp. R239-R246 ◽  
Author(s):  
H. O. Portner ◽  
D. M. Webber ◽  
R. G. Boutilier ◽  
R. K. O'Dor
Keyword(s):  
Venous Blood ◽  
Vena Cava ◽  
Arterial Oxygen ◽  
High Pco2 ◽  
Oxygen Binding ◽  
Intracellular Acidosis ◽  
Acid Base ◽  
Classical Function ◽  
Acid Base Status ◽  
Loligo Pealei

Squid (Illex illecebrosus, Loligo pealei) were cannulated in the vena cava and swum in a Beamish-type respirometer. Gas tensions and acid-base variables as well as octopine levels were estimated in samples of the mantle and of venous blood collected from quiescent, exercised, and recovered animals. When exhausted, both species exhibited a decrease in vena cava oxygen tensions and a slight alkalosis. With high swimming speeds prior to exhaustion in Illex a slight acidosis developed in the blood, which was linked to a severe intracellular acidosis. Generally, the drop in intracellular pH was linearly correlated with octopine accumulation in this species. Metabolic proton (and end-product) release from the mantle, however, was minimal, thus protecting arterial oxygen binding. High PCO2 values in the mantle of both species lead to the conclusion that the vena cava values analyzed in this and all literature studies on unrestrained cephalopods may not reflect the scope of respiratory acid-base changes in venous blood. Although metabolic changes in blood acid-base status are negligible, the respiratory acidification of venous mantle blood may allow for a classical function of Bohr and Haldane effects in these animals.

scholarly journals Anaerobic Metabolism and Changes in Acid—Base Status: Quantitative Interrelationships and PH Regulation in the Marine Worm Sipunculus Nudus

1987 ◽  
Vol 131 (1) ◽  
pp. 89-105
Author(s):  
HANS-OTTO PÖRTNER
Keyword(s):  
Anaerobic Metabolism ◽  
Ph Value ◽  
Ph Regulation ◽  
Proton Exchange ◽  
Acid Base ◽  
Base Parameters ◽  
Sipunculus Nudus ◽  
Theoretical Predictions ◽  
Acid Base Status ◽  
Proton Generation

The quantitative influence of anaerobic metabolism on acid—base status and on acid-base regulation is investigated in Sipunculus nudus L. Proton generation by metabolism is calculated from theoretical predictions. The quantitative comparison of metabolic protons with non-respiratory protons found in the acid—base status is performed assuming a simplified model of the total animal. Taking the protonequivalent ion exchange between animals and ambient water into account, changes in the anaerobic acid—base status can be explained exclusively by proton generation in metabolism. It is concluded that the classical concept of acid—base physiology is adequate and that the consideration of strong ions is not required for a quantitative treatment of the acid—base status. The hypothesis that a quantitative correlation exists between metabolic and acid—base events is tested by comparing changes in acid—base status and in metabolism in animals exhibiting different metabolic rates. For this purpose, a method is developed for the calculation of intracellular pH from metabolite concentrations and extracellular acid—base parameters. Proton exchange between intra-and extracellular compartments, which is found to depend upon the total amount of accumulated non-respiratory protons, demonstrates that pHi is regulated even during anaerobiosis. The defended pH, value, however, is lower during anaerobiosis than during subsequent recovery. Note: Address for reprint requests

Squid (Lolliguncula brevis) life in shallow waters: oxygen limitation of metabolism and swimming performance.

1996 ◽  
Vol 199 (4) ◽  
pp. 911-921 ◽  
Author(s):  
E Finke ◽  
H O Pörtner ◽  
P G Lee ◽  
D M Webber
Keyword(s):  
Anaerobic Threshold ◽  
Energy Production ◽  
Anaerobic Metabolism ◽  
Swimming Performance ◽  
Transport Cost ◽  
Energy Requirements ◽  
Swimming Velocity ◽  
Anaerobic Energy ◽  
Mean Pressure ◽  
Lolliguncula Brevis

Squid (Lolliguncula brevis) were exercised in a tunnel respirometer during a stepwise increase in water velocity in order to evaluate the anaerobic threshold, i.e. the critical swimming speed above which anaerobic metabolism contributes to energy production. The average anaerobic threshold was found at speeds of 1.5-2 mantle lengths s-1. Above this velocity, alpha-glycerophosphate, succinate and octopine started to accumulate in the mantle tissue. ATP levels fell and phospho-L-arginine was progressively depleted, while the levels of glucose 6-phosphate and inorganic phosphate rose. The finding of a simultaneous onset of anaerobic metabolism in the cytosol and the mitochondria indicates that a limited oxygen supply to the mitochondria elicits anaerobic energy production. This finding is opposite to the situation found in many other vertebrate and invertebrate species, in which energy requirements in excess of aerobic energy production are covered by anaerobic metabolism, with mitochondria remaining aerobic. In L. brevis, swimming at higher speeds is associated with a small factorial increase in metabolic rate based on a high resting rate of oxygen consumption. Pressure recordings in the mantle cavity support this finding, indicating a high basal level of spontaneous activity at rest and a small rise in mean pressure at higher swimming velocity. Bursts of higher pressures from the jet support elevated swimming speeds and may explain the early transition to anaerobic energy production which occurs when pressure amplitudes exceed 1.2-1.5 kPa or when mean pressure rises above 0.22-0.25 kPa. The finding of mitochondrial hypoxia at a low critical speed in these squid is interpreted to be related to their life in shallow coastal and bay waters, which limits the necessity to maintain high swimming velocities. At increased swimming velocities, the animals oscillate between periods of high and low muscular activity. This behaviour is interpreted to reduce transport cost and to permit a longer-term net use of anaerobic resources when speed exceeds the critical value or when the squid dive into hypoxic waters. The simultaneous onset of anaerobic metabolism in the cytosol and the mitochondria emphasizes that squid generally make maximal use of available oxygen under resting conditions, when their energy requirements are the highest among marine invertebrates.

Conservation of phosphorylation state of cardiac phosphofructokinase during in vitro hypothermic hypoxia

2000 ◽  
Vol 279 (5) ◽  
pp. H2151-H2158 ◽  
Author(s):  
Randy P. Pulis ◽  
Beatrice M. Wu ◽  
Norman M. Kneteman ◽  
Thomas A. Churchill
Keyword(s):  
Posttranslational Modification ◽  
Energy Production ◽  
Anaerobic Metabolism ◽  
Energy Charge ◽  
Metabolic Effects ◽  
Adenylate Energy Charge ◽  
Three Solutions ◽  
University Of Wisconsin ◽  
Anaerobic Energy

We investigated the metabolic effects of buffering agents α-amino-4-imidazole-propionic acid (Histidine), N,N-bis(2-hydroxyethyl)glycine (bicine), N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES) on anaerobic energy production (via glycolysis) and conservation of key regulatory enzyme activity, and phosphofructokinase (PFK) throughout prolonged hypothermic hypoxia in porcine hearts. Hearts from 35 to 40 kg pigs were flushed with one of the following five solutions: St. Thomas' Hospital solution (STHS); modified University of Wisconsin (UW) solution; and three solutions containing modified UW plus 90 mM of histidine, bicine, or BES. The hearts were then stored at 4°C for 10 h. After 10 h of hypothermic hypoxia, lactate values were 6.7–12.9 μmol/g higher than control; this reflected an increase in anaerobic end product of 35–67%. The consequences of enhanced anaerobic metabolism were higher ATP, total adenylate, Energy Charge, and ATP/ADP ratios in most of the buffered groups after 4–10 h cold storage; effectiveness of the buffers employed correlated with buffering capacity (BES proved to be the most effective). PFK remained activated throughout most of the 10-h period in hearts stored with buffers and did not undergo the rapid inactivation experienced by hearts stored in STHS. Conservation of PFK integrity with buffering agents was not related to a pH-mediated event; changes in kinetic parameters suggested that this protection was due to an irreversible posttranslational modification, specifically a dephosphorylation event.

scholarly journals Human muscle net K+ release during exercise is unaffected by elevated anaerobic metabolism, but reduced after prolonged acclimatization to 4,100 m

2010 ◽  
Vol 299 (1) ◽  
pp. R306-R313 ◽  
Author(s):  
Nikolai B. Nordsborg ◽  
José A. L. Calbet ◽  
Mikael Sander ◽  
Gerrit van Hall ◽  
Carsten Juel ◽  
...  
Keyword(s):  
Exercise Intensity ◽  
Energy Production ◽  
Anaerobic Metabolism ◽  
Hypoxic Exposure ◽  
Bicycle Exercise ◽  
Hypoxic Conditions ◽  
Anaerobic Energy ◽  
K Release ◽  
Bicycle Exercise Test ◽  
Venous Plasma

It was investigated whether skeletal muscle K+ release is linked to the degree of anaerobic energy production. Six subjects performed an incremental bicycle exercise test in normoxic and hypoxic conditions prior to and after 2 and 8 wk of acclimatization to 4,100 m. The highest workload completed by all subjects in all trials was 260 W. With acute hypoxic exposure prior to acclimatization, venous plasma [K+] was lower ( P < 0.05) in normoxia (4.9 ± 0.1 mM) than hypoxia (5.2 ± 0.2 mM) at 260 W, but similar at exhaustion, which occurred at 400 ± 9 W and 307 ± 7 W ( P < 0.05), respectively. At the same absolute exercise intensity, leg net K+ release was unaffected by hypoxic exposure independent of acclimatization. After 8 wk of acclimatization, no difference existed in venous plasma [K+] between the normoxic and hypoxic trial, either at submaximal intensities or at exhaustion (360 ± 14 W vs. 313 ± 8 W; P < 0.05). At the same absolute exercise intensity, leg net K+ release was less ( P < 0.001) than prior to acclimatization and reached negative values in both hypoxic and normoxic conditions after acclimatization. Moreover, the reduction in plasma volume during exercise relative to rest was less ( P < 0.01) in normoxic than hypoxic conditions, irrespective of the degree of acclimatization (at 260 W prior to acclimatization: −4.9 ± 0.8% in normoxia and −10.0 ± 0.4% in hypoxia). It is concluded that leg net K+ release is unrelated to anaerobic energy production and that acclimatization reduces leg net K+ release during exercise.

scholarly journals Acid-base regulation, metabolism and energetics in sipunculus nudus as a function of ambient carbon dioxide level

1998 ◽  
Vol 201 (1) ◽  
pp. 43-55 ◽  
Author(s):  
H O Pörtner ◽  
A Reipschläger ◽  
N Heisler
Keyword(s):  
Ammonium Excretion ◽  
Ion Transfer ◽  
Energy Status ◽  
Intracellular Acidosis ◽  
Acid Base ◽  
Sipunculus Nudus ◽  
Acid Base Status ◽  
Net Release

Changes in the rates of oxygen consumption and ammonium excretion, in intra- and extracellular acid-base status and in the rate of H+-equivalent ion transfer between animals and ambient water were measured during environmental hypercapnia in the peanut worm Sipunculus nudus. During exposure to 1 % CO2 in air, intracellular and coelomic plasma PCO2 values rose to levels above those expected from the increase in ambient CO2 tension. Simultaneously, coelomic plasma PO2 was reduced below control values. The rise in PCO2 also induced a fall in intra- and extracellular pH, but intracellular pH was rapidly and completely restored. This was achieved during the early period of hypercapnia at the expense of a non-respiratory increase in the extracellular acidosis. The pH of the extracellular space was only partially compensated (by 37 %) during long-term hypercapnia. The net release of basic equivalents under control conditions turned to a net release of protons to the ambient water before a net, albeit reduced, rate of base release was re-established after a new steady state had been achieved with respect to acid-base parameters. Hypercapnia also affected the mode and rate of metabolism. It caused the rate of oxygen consumption to fall, whereas the rate of ammonium excretion remained constant or even increased, reflecting a reduction of the O/N ratio in both cases. The transient intracellular acidosis preceded a depletion of the phosphagen phospho-l-arginine, an accumulation of free ADP and a decrease in the level of Gibbs free energy change of ATP hydrolysis, before replenishment of phosphagen and restoration of pHi and energy status occurred in parallel. In conclusion, long-term hypercapnia in vivo causes metabolic depression, a parallel shift in acid-base status and increased gas partial pressure gradients, which are related to a reduction in ventilatory activity. The steady-state rise in H+-equivalent ion transfer to the environment reflects an increased rate of production of protons by metabolism. This observation and the reduction of the O/N ratio suggest that a shift to protein/amino acid catabolism has taken place. Metabolic depression prevails, with completely compensated intracellular acidosis during long-term hypercapnia eliminating intracellular pH as a significant factor in the regulation of metabolic rate in vivo. Fluctuating levels of the phosphagen, of free ADP and in the ATP free energy change values independent of pH are interpreted as being correlated with oscillating ATP turnover rates during early hypercapnia and as reflecting a tight coupling of ATP turnover and energy status via the level of free ADP.

To Manage Infantile Hypertrophic Pyloric Stenosis by "Double-Y Pyloromyotomy" is a better Surgical Approach

2014 ◽  
Vol 1 (2) ◽  
pp. 143-147
Author(s):  
Md. Ansar Ali ◽  
Kaniz Hasina ◽  
Shahnoor Islam ◽  
Md. Ashraf Ul Huq ◽  
Md. Mahbub-Ul Alam ◽  
...  
Keyword(s):  
Weight Gain ◽  
Pyloric Stenosis ◽  
Hypertrophic Pyloric Stenosis ◽  
Treatment Modalities ◽  
Infantile Hypertrophic Pyloric Stenosis ◽  
Postoperative Vomiting ◽  
Acid Base ◽  
Feeding Regimes ◽  
Acid Base Status ◽  
Postoperative Feeding

Background: Different treatment modalities and procedures have been tried for the management of infantile hypertrophic pyloric stenosis. But surgery remains the mainstay for management of IHPS. Ramstedt’s pyloromyotomy was described almost over a hundred years ago and to date remains the surgical technique of choice. An alternative and better technique is the double-Y pyloromyotomy, which offer better results for management of this common condition.Methods: A prospective comparative interventional study of 40 patients with IHPS was carried out over a period of 2 years from July 2008 to July 2010. The patients were divided into 2 equal groups of 20 patients in each. The study was designed that all patients selected for study were optimized preoperatively regarding to hydration, acid-base status and electrolytes imbalance. All surgeries were performed after obtaining informed consent. Standard preoperative preparation and postoperative feeding regimes were used. The patients were operated on an alternate basis, i.e., one patient by Double-Y Pyloromyotomy(DY) and the next by aRamstedt’s Pyloromyotomy (RP). Data on patient demographics, operative time, anesthesia complications, postoperative complications including vomiting and weight gain were collected. Patients were followed up for a period of 3 months postoperatively. Statistical assessments were done by using t test.Results: From July 2008 through July 2010, fourty patients were finally analyzed for this study. Any statistical differences were observed in patient population regarding age, sex, weight at presentation, symptoms and clinical condition including electrolytes imbalance and acid-base status were recorded. Significant differences were found in postoperative vomiting and weight gain. Data of post operative vomiting and weight gain in both groups were collected. Vomiting in double-Y(DY) pyloromyotomy group (1.21 ± 0.45days) vs Ramstedt’s pyloromyotomy (RP) group(3.03 ± 0.37days) p= 0.0001.Weight gain after 1st 10 days DY vs RP is ( 298 ± 57.94 gm vs193±19.8 gm p=0.0014), after 1 month (676.67±149.84 gm vs 466.67 ± 127.71 gm, p=0.0001), after 2months (741.33± 278.74 gm vs 490±80.62 gm, p=0.002) and after 3 months (582±36.01gm vs 453.33±51.64 gm, p=0.0001).No long-term complications were reported and no re-do yloromyotomy was needed.Conclusion: The double-Y pyloromyotomy seems to be a better technique for the surgical management of IHPS. It may offer a better functional outcome in term of postoperative vomiting and weight gain.DOI: http://dx.doi.org/10.3329/jpsb.v1i2.19532

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