Extracellular Acid-Base Balance in Aquatic Animals as a Function of the Ionic Composition and the Acid-Base Balance of the Ambient Water

Author(s):  
Jean-Paul Truchot
1986 ◽  
Vol 64 (5) ◽  
pp. 1054-1057 ◽  
Author(s):  
B. L. Tufts ◽  
D. P. Toews

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.


1989 ◽  
Vol 67 (2) ◽  
pp. 563-569 ◽  
Author(s):  
S. Javaheri ◽  
J. F. Freidel ◽  
P. J. Davis

The purpose of this study was to investigate the effects of furosemide, an inhibitor of NaCl cotransport, on cisternal cerebrospinal fluid (CSF) acid-base balance during acute respiratory acidosis (ARA). We measured blood and CSF acid-base variables in two groups (n = 7 in each) of anesthetized, paralyzed, and mechanically ventilated dogs with bilateral ligation of renal pedicles (to eliminate saluresis). After base-line samples were obtained (-1 h), furosemide (50 mg/kg) was administered intravenously within 15 min (group II); group I received an equal volume of half-normal saline. ARA was induced 1 h later (0 h) and arterial CO2 tension was maintained between 55 and 60 Torr for 5 h. Mean cisternal CSF PCO2 was 42.8 +/- 2.6 and 39.5 +/- 1.7 Torr, respectively in groups I and II and rose approximately 20 Torr during ARA. In group I, CSF [HCO3-] was 22.0 +/- 1.0, 24.8 +/- 0.6, and 25.4 +/- 1.6 meq/l, respectively at 0, 2.5, and 5 h. Respective values for group II were 22.2 +/- 1.3, 24.3 +/- 1.8, and 24.6 +/- 1.0 meq/l. These values were not significantly different from each other. In each group, CSF [Na+-Cl-] increased significantly during ARA, but the changes were not significantly different when the two groups were compared. We conclude that furosemide at the dose used in the present study does not change ionic composition and acid-base balance of cisternal CSF compared with control. Because changes in CSF [Na+-Cl-] during ARA were similar in both groups, any inhibition of Cl- influx into CSF by furosemide should have been proportional to that of Na+.


2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
María M. Adeva-Andany ◽  
Natalia Carneiro-Freire ◽  
Cristóbal Donapetry-García ◽  
Eva Rañal-Muíño ◽  
Yosua López-Pereiro

Human plasma is an aqueous solution that has to abide by chemical rules such as the principle of electrical neutrality and the constancy of the ionic product for water. These rules define the acid-base balance in the human body. According to the electroneutrality principle, plasma has to be electrically neutral and the sum of its cations equals the sum of its anions. In addition, the ionic product for water has to be constant. Therefore, the plasma concentration of hydrogen ions depends on the plasma ionic composition. Variations in the concentration of plasma ions that alter the relative proportion of anions and cations predictably lead to a change in the plasma concentration of hydrogen ions by driving adaptive adjustments in water ionization that allow plasma electroneutrality while maintaining constant the ionic product for water. The accumulation of plasma anions out of proportion of cations induces an electrical imbalance compensated by a fall of hydroxide ions that brings about a rise in hydrogen ions (acidosis). By contrast, the deficiency of chloride relative to sodium generates plasma alkalosis by increasing hydroxide ions. The adjustment of plasma bicarbonate concentration to these changes is an important compensatory mechanism that protects plasma pH from severe deviations.


1976 ◽  
Vol 64 (1) ◽  
pp. 159-171
Author(s):  
F. B. Eddy

1. The respiratory properties of rainbow-trout blood were investigated in acid-stressed fish. In the first group acid was introduced into the bloodstream and in the second the carbon dioxide content of the ambient water was increased. 2. Initially the introduction of acid to the blood caused a decrease in blood pH and bicarbonate, and increases in oxygen uptake and ventilation volume. After 2–3 h these values had returned to the control levels. 3. Trout subjected to high ambient CO2 (about 10 mmHg) showed a decrease in blood pH while PCO2 and bicarbonate increased. After 8 h the trout began to show signs of compensation to the acidosis. 4. In each experiment the blood PO2 was little changed but blood O2 content was decreased and tended not to resume the control value even after several hours. 5. The results are discussed in terms of the various acid-base mechanisms thought to be available to the fish. These include branchial ion exchanges and the possible buffering roles of the extracellular and intracellular fluids.


1983 ◽  
Vol 54 (1) ◽  
pp. 3-12 ◽  
Author(s):  
E. E. Nattie

This review emphasizes the importance of strong ions in the regulation of cerebrospinal fluid (CSF) acid-base balance. In a solution like CSF that is devoid of nonbicarbonate buffers. [H+] and [HCO-3] are dependent variables, the independent variables being the CO2 partial pressure (PCO2) and the strong ion difference. Any measureable changes in CSF [HCO-3] and any change in [H+] that occur independent of changes in PCO2 must be accompanied by, if not caused by, changes in strong ions. The role of H+ and HCO-3 vs. strong ions in the ionic mechanisms of CSF acid-base regulation is unknown. For example, these mechanisms could depend only on changes in strong ions that accompany acid-base disorders, or they could be triggered by changes in [H+] or PCO2. These ideas are presented within the context of current concepts concerning the relationship of CSF to brain interstitial fluid (ISF) and the importance of choroid plexus and blood-brain barrier mechanisms in determining CSF and ISF ionic composition. Studies concerning CSF strong ions in normal and abnormal acid-base states are reviewed.


2014 ◽  
Vol 84 (3-4) ◽  
pp. 0206-0217 ◽  
Author(s):  
Seyedeh-Elaheh Shariati-Bafghi ◽  
Elaheh Nosrat-Mirshekarlou ◽  
Mohsen Karamati ◽  
Bahram Rashidkhani

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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