scholarly journals Compensation of progressive hypercapnia in the toad (Bufo marinus) and the bullfrog (Rana catesbeiana)

1990 ◽  
Vol 148 (1) ◽  
pp. 293-302
Author(s):  
D. P. Toews ◽  
D. F. Stiffler
Keyword(s):  
Ion Transport ◽  
Rana Catesbeiana ◽  
Bufo Marinus ◽  
Extracellular Ph ◽  
Ion Flux ◽  
Acid Base Balance ◽  
Acid Base ◽  
Base Balance ◽  
Co2 Level ◽  
Toad Bufo

Toads (Bufo marinus L.) and bullfrogs (Rana catesbeiana Shaw) were subjected to a series of 24 h step increases in aerial CO2 (2, 4, 6 and 8%) to assess the degree of extracellular pH compensation at each CO2 level and to ascertain the importance of cutaneous ion transport in this process. Elevation of plasma [HCO3-] occurs during the 24 h period, with the bullfrogs showing a greater ability to compensate at each step. There was no indication that a [HCO3-] threshold of 30 mmol l-1 existed in either species, although bullfrogs appeared to have a greater compensatory potential when exposed to the higher levels of CO2. The results of the ion flux experiments suggest that neither the terrestrial Bufo nor the semi-aquatic Rana use their skin to any great extent for acid-base balance during hypercapnia.

Renal function and acid-base balance in the toad Bufo marinus during short-term dehydration

1986 ◽  
Vol 64 (5) ◽  
pp. 1054-1057 ◽  
Author(s):  
B. L. Tufts ◽  
D. P. Toews
Keyword(s):  
Renal Function ◽  
Bufo Marinus ◽  
Ambient Water ◽  
Acid Base Balance ◽  
Acid Base ◽  
Short Term ◽  
Base Balance ◽  
Toad Bufo ◽  
Normal Acid ◽  
Tubular Component

Specimens of Bufo marinus (L.) were cannulated in both ureters to partition between the regulatory contributions of the kidney and urinary bladder. These bladder-bypassed animals were then exposed to 10 h of dehydration in air and renal function and acid–base balance were assessed. The results indicated that the kidney showed an almost immediate response to dehydration which consisted of a large glomerular and smaller tubular component. Bypassing and emptying of the bladder and the removal of the ambient water had no effect on the animal's ability to maintain normal acid–base balance.

scholarly journals Extracellular Acid-Base Balance and Ion Transport Between Body Fluid Compartments

Physiology ◽  
2017 ◽  
Vol 32 (5) ◽  
pp. 367-379 ◽  
Author(s):  
Julian L. Seifter ◽  
Hsin-Yun Chang
Keyword(s):  
Ion Transport ◽  
Ph Regulation ◽  
Extracellular Fluid ◽  
Transport Processes ◽  
Electrolyte Balance ◽  
Ph Homeostasis ◽  
Acid Base Balance ◽  
Acid Base ◽  
Base Balance ◽  
Fluid Compartments

Clinical assessment of acid-base disorders depends on measurements made in the blood, part of the extracellular compartment. Yet much of the metabolic importance of these disorders concerns intracellular events. Intracellular and interstitial compartment acid-base balance is complex and heterogeneous. This review considers the determinants of the extracellular fluid pH related to the ion transport processes at the interface of cells and the interstitial fluid, and between epithelial cells lining the transcellular contents of the gastrointestinal and urinary tracts that open to the external environment. The generation of acid-base disorders and the associated disruption of electrolyte balance are considered in the context of these membrane transporters. This review suggests a process of internal and external balance for pH regulation, similar to that of potassium. The role of secretory gastrointestinal epithelia and renal epithelia with respect to normal pH homeostasis and clinical disorders are considered. Electroneutrality of electrolytes in the ECF is discussed in the context of reciprocal changes in Cl−or non Cl−anions and [Formula: see text].

The effects of enforced activity on ventilation, circulation and blood acid-base balance in the aquatic gill-less urodele, Cryptobranchus alleganiensis; a comparison with the semi-terrestrial anuran, Bufo marinus

1980 ◽  
Vol 84 (1) ◽  
pp. 289-302
Author(s):  
R. G. Boutilier ◽  
D. G. McDonald ◽  
D. P. Toews
Keyword(s):  
Recovery Period ◽  
Respiratory Acidosis ◽  
Bufo Marinus ◽  
Acid Base Balance ◽  
Acid Base ◽  
Post Exercise ◽  
Arterial Blood ◽  
Cryptobranchus Alleganiensis ◽  
Base Balance ◽  
Lower Magnitude

A combined respiratory and metabolic acidosis occurs in the arterial blood immediately following 30 min of strenuous activity in the predominantly skin-breathing urodele, Cryptobranchus alleganiensis, and in the bimodal-breathing anuran, Bufo marinus, at 25 degrees C. In Bufo, the bulk of the post-exercise acidosis is metabolic in origin (principally lactic acid) and recovery is complete within 4-8 h. In the salamander, a lower magnitude, longer duration, metabolic acid component and a more pronounced respiratory acidosis prolong the recovery period for up to 22 h post-exercise. It is suggested that fundamental differences between the dominant sites for gas exchange (pulmonary versus cutaneous), and thus in the control of respiratory acid-base balance, may underline the dissimilar patterns of recovery from exercise in these two species.

Interactions between cutaneous ion-exchange mechanisms and acid–base balance in amphibians

1989 ◽  
Vol 67 (12) ◽  
pp. 3070-3077 ◽  
Author(s):  
Daniel F. Stiffler
Keyword(s):  
Ion Exchange ◽  
Ion Transport ◽  
Extracellular Fluid ◽  
Ambystoma Tigrinum ◽  
Acid Base Balance ◽  
Acid Base ◽  
Homeostatic Process ◽  
Base Balance ◽  
Net Flux ◽  
Exercise Induced

It has been suspected for over 50 years that amphibian ion exchange involves independent transport of Na+ and Cl− in an inward direction across the skin in exchange for acidic cations and basic anions, respectively. Although a role for such exchange mechanisms has obvious utility in acid–base balance, their participation in this homeostatic process has only recently been documented. We now know that in aquatic Ambystoma tigrinum, the presence of NaCl in the water bathing the skin is required for acid–base regulatory responses to hypercapnia and exercise-induced lactacidosis. Acidotic and alkalotic conditions in the animals' extracellular fluid cause changes in both Na+ and Cl− influx and net flux which are consistent with a role for ion transport in acid–base balance. These processes appear to be under the control of both catecholamines and interrenal steroids.

scholarly journals Switch from Metabolic to Ventilatory Compensation of Extracellular pH in Crayfish

1988 ◽  
Vol 137 (1) ◽  
pp. 411-420 ◽  
Author(s):  
B. Burtin ◽  
J.-C. Massabuau
Keyword(s):  
Metabolic Acidosis ◽  
Partial Pressure ◽  
Ph Regulation ◽  
Extracellular Ph ◽  
Hypercapnic Acidosis ◽  
Acid Base Balance ◽  
Acid Base ◽  
Astacus Leptodactylus ◽  
Partial Pressure Of Co2 ◽  
Base Balance

The mechanisms of extracellular pH regulation were studied in crayfish Astacus leptodactylus under conditions that were either favourable or unfavourable for ionoregulation. Animals in intermoult or premoult stages were kept in normoxic artificial waters at 13°C. In intermoult, acid—base balance (ABB) and ionoregulatory disturbances were induced by increasing the ambient partial pressure of CO2 (PwCOCO2), by decreasing the concentration of NaCl in the water ([NaCl]w) or by associating both changes. In premoult we took advantage of the spontaneously occurring endogenous problems of ionoregulation which are linked to shell shedding. In intermoult, an increase of PwCOCO2 alone induced a hypercapnic acidosis compensated by metabolic means, whereas in association with a decrease of [NaCl]w (which induced a decrease of [NaCl] in the haemolymph) it led to a ventilatory compensation. In intermoult a decrease of [NaCl]w alone induced a metabolic acidosis that was compensated by metabolic means, whereas in premoult it was compensated by ventilatory adjustments. It is concluded that when water breathers are facing experimentally induced or spontaneous ionoregulatory problems, compensation for superimposed ABB disturbances can be made by ventilatory adjustments instead of by metabolic means.

Effects of feeding on metabolism, gas transport, and acid-base balance in the bullfrog Rana catesbeiana

2000 ◽  
Vol 278 (1) ◽  
pp. R185-R195 ◽  
Author(s):  
Morten Busk ◽  
Frank B. Jensen ◽  
Tobias Wang
Keyword(s):  
Rana Catesbeiana ◽  
Sartorius Muscle ◽  
Acid Base Balance ◽  
Acid Base ◽  
Arterial Blood ◽  
Arterial Ph ◽  
Integrative Study ◽  
Base Balance ◽  
Arterial Blood Oxygen ◽  
Lactate Levels

Massive feeding in ectothermic vertebrates causes changes in metabolism and acid-base and respiratory parameters. Most investigations have focused on only one aspect of these complex changes, and different species have been used, making comparison among studies difficult. The purpose of the present study was, therefore, to provide an integrative study of the multiple physiological changes taking place after feeding. Bullfrogs ( Rana catesbeiana) partly submerged in water were fed meals (mice or rats) amounting to ∼[Formula: see text] of their body weight. Oxygen consumption increased and peaked at a value three times the predigestive level 72–96 h after feeding. Arterial[Formula: see text] decreased slightly during digestion, whereas hemoglobin-bound oxygen saturation was unaffected. Yet, arterial blood oxygen content was pronouncedly elevated because of a 60% increase in hematocrit, which appeared mediated via release of red blood cells from the spleen. Gastric acid secretion was associated with a 60% increase in plasma [Formula: see text]concentration[Formula: see text]]) 48 h after feeding. Arterial pH only increased from 7.86 to 7.94, because the metabolic alkalosis was countered by an increase in[Formula: see text] from 10.8 to 13.7 mmHg. Feeding also induced a small intracellular alkalosis in the sartorius muscle. Arterial pH and [Formula: see text] returned to control values 96–120 h after feeding. There was no sign of anaerobic energy production during digestion as plasma and tissue lactate levels remained low and intracellular ATP concentration stayed high. However, phosphocreatine was reduced in the sartorius muscle and ventricle 48 h after feeding.

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

2014 ◽  
Vol 84 (3-4) ◽  
pp. 0206-0217 ◽  
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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