Studies on the extra- and intracellular acid-base status and its role on metabolic depression in the land snail Helix lucorum (L.) during estivation

2002 ◽  
Vol 172 (4) ◽  
pp. 347-354 ◽  
Author(s):  
Michaelidis B.
1999 ◽  
Vol 202 (12) ◽  
pp. 1667-1675
Author(s):  
B. Michaelidis ◽  
A. Pallidou ◽  
P. Vakouftsi

The aims of the present study were to describe a possible correlation between the regulation of the key glycolytic enzyme pyruvate kinase and the acid-base status in the haemolymph and in several other tissues of land snails during anoxia. To illustrate whether such a relationship exists, we determined (i) the acid-base variables in the haemolymph and tissues of the land snail Helix lucorum, (ii) the kinetic properties of pyruvate kinase from several tissues and (iii) the levels of the anaerobic end-products d-lactate and succinate in the haemolymph and tissues of aerobic and anoxic Helix lucorum. The results showed that the pH of haemolymph (pHe) decreased significantly over the first 20 h of anoxia and then recovered slowly towards control values. A similar pattern was observed for intracellular pH (pHi), which decreased significantly over the first 16 h of anoxia and slowly returned towards control levels. The reduction and recovery of pHi and pHe seem to reflect the rate of anaerobic metabolism. The main anaerobic end-products, d-lactate and succinate, accumulated rapidly during the initial stages of anoxia and more slowly as anoxia progressed. The decrease in the rate of accumulation of anaerobic end-products during prolonged anoxia was due to the conversion of tissue pyruvate kinase to a less active form. The results demonstrate a correlation between pyruvate kinase down-regulation and the recovery of acid-base status in the haemolymph and the tissues of land snails during anoxia.


1991 ◽  
Vol 156 (1) ◽  
pp. 153-171 ◽  
Author(s):  
YONG TANG ◽  
ROBERT G. BOUTILIER

The intracellular acid-base status of white muscle of freshwater (FW) and seawater (SW) -adapted rainbow trout was examined before and after exhaustive exercise. Exhaustive exercise resulted in a pronounced intracellular acidosis with a greater pH drop in SW (0.82 pH units) than in FW (0.66 pH units) trout; this was accompanied by a marked rise in intracellular lactate levels, with more pronounced increases occurring in SW (54.4 mmoll−1) than in FW (45.7 mmoll−1) trout. Despite the more severe acidosis, recovery was faster in the SW animals, as indicated by a more rapid clearance of metabolic H+ and lactate loads. Compartmental analysis of the distribution of metabolic H+ and lactate loads showed that the more rapid recovery of pH in SW trout could be due to (1) their greater facility for excreting H+ equivalents to the environmental water [e.g. 15.5 % (SW) vs 5.0 % (FW) of the initial H+ load was stored in external water at 250 min post-exercise] and, to a greater extent, (2) the more rapid removal of H+, facilitated via lactate metabolism in situ (white muscle) and/or the Cori cycle (e.g. heart, liver). The slower pH recovery in FW trout may also be due in part to greater production of an ‘unmeasured acid’ [maximum approx. 8.5 mmol kg−1 fish (FW) vs approx. 6 mmol kg−1 fish (SW) at 70–130 min post-exercise] during the recovery period. Furthermore, the analysis revealed that H+-consuming metabolism is quantitatively the most important mechanism for the correction of an endogenously originating acidosis, and that extracellular pH normalization gains priority over intracellular pH regulation during recovery of acid-base status following exhaustive exercise.


1987 ◽  
Vol 130 (1) ◽  
pp. 13-25 ◽  
Author(s):  
R. G. BOUTILIER ◽  
M. L. GLASS ◽  
N. HEISLER

Blood gases, and parameters of the extracellular and intracellular acid-base status, were measured in the anuran amphibians Bufo marinus and Xenopus laevis acclimated to temperatures of 10, 20 and 30°C for 12 days. Arterial POO2 rose with temperature so that approximately constant oxygen saturation of the blood was maintained, a phenomenon explained on the basis of models for O2 transport in animals with central vascular shunts and temperature-dependent shifts in O2 equilibrium characteristics. Arterial plasma pH of both species varied inversely with temperature, the pH/temperature coefficient being not significantly different from that required for constant relative alkalinity or dissociation of imidazole. The change in plasma pH was brought about mainly by changes in PCOCO2 although plasma bicarbonate concentration also changed significantly. Intracellular pH/temperature relationships were found to be non-linear in most of the tissues. There was considerable variability among body tissue compartments and between the two species. These data confirm that the various tissue compartments in ectotherms maintain unique ΔpH/Δt relationships, and indicate that measurement of extracellular pH as a function of temperature is not a good indicator for alphastat-type, temperature-dependent, acid-base regulation.


2014 ◽  
Vol 1 (2) ◽  
pp. 143-147
Author(s):  
Md. Ansar Ali ◽  
Kaniz Hasina ◽  
Shahnoor Islam ◽  
Md. Ashraf Ul Huq ◽  
Md. Mahbub-Ul Alam ◽  
...  

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


Sign in / Sign up

Export Citation Format

Share Document