scholarly journals Acid-Base Balance in Callinectes Sapidus During Acclimation from High to Low Salinity

1982 ◽  
Vol 101 (1) ◽  
pp. 255-264 ◽  
Author(s):  
RAYMOND P. HENRY ◽  
JAMES N. CAMERON

When transferred from 865 to 250 m-osmol salinity, the blue crab C. sapidus maintains its blood Na+ and Cl− concentrations significantly above those in the medium. When branchial carbonic anhydrase is inhibited by acetazolamide, ion regulation fails and the animals do not survive the transfer. An alkalosis occurs in the blood at low salinity, indicated by an increase in HCO3− and pH at constant PCO2. The alkalosis is closely correlated with an increase in the Na+-Cl− difference, a convenient indicator of the overall strong ion difference. The contribution of changes in PCO2 to acid-base changes was negligible, but the change in the total weak acid (proteins) may be important. It is suggested that the change in blood acidbase status with salinity is related to an increase in the strong ion difference, which changes during the transition from osmoconformity to osmoregulation in the blue crab, and which is related to both carbonic anhydrase and ionactivated ATPases. Note:

1985 ◽  
Vol 5 (2) ◽  
pp. 188-206 ◽  
Author(s):  
C. P. Mangum ◽  
B. R. McMahon ◽  
P. L. deFur ◽  
M. G. Wheatly

1987 ◽  
Vol 252 (2) ◽  
pp. R348-R352 ◽  
Author(s):  
M. Shimizu ◽  
D. R. Jones

Measurements of all the major independent variables [arterial CO2 tension (PaCO2); strong-ion difference ([SID]), and total protein content, which approximate total weak acid concentration in plasma] are essential for understanding changes in acid-base balance in plasma. During involuntary submergence of 1, 2, or 4 min, PaCO2 in ducks increased and arterial pH (pHa) decreased. During 1-min dives there were no significant changes in any strong ions. In both 2- and 4-min dives, there was a significant increase in [lactate-], but because of an increase in equal magnitude of [Na+], [SID] did not change. During recovery from all dives the plasma remained acidotic for several minutes, although PaCO2 fell below predive levels in less than 1 min. [Lactate-] increased in the recovery period. There were no changes in total protein content during submergence or recovery. Breathing 100% O2 before 2-min dives caused a reduction in [lactate-] production and release during and after the dive, although due to a marked increased in PaCO2, pHa fell as low as in 4-min dives after breathing air. After 1 min of recovery, pHa returned to normal along with the restoration of the predive level of PaCO2. We conclude that the acidosis during involuntary submergence is due solely to an increase in PaCO2, whereas in recovery it is caused by decreased [SID].


2001 ◽  
Vol 280 (2) ◽  
pp. R481-R487 ◽  
Author(s):  
Robert J. Preston ◽  
Aaron P. Heenan ◽  
Larry A. Wolfe

In accordance with Stewart's physicochemical approach, the three independent determinants of plasma hydrogen ion concentration ([H+]) were measured at rest and during exercise in the follicular (FP) and luteal phase (LP) of the human menstrual cycle. Healthy, physically active women with similar physical characteristics were tested during either the FP ( n = 14) or LP ( n = 14). Arterialized blood samples were obtained at rest and after 5 min of upright cycling at both 70 and 110% of the ventilatory threshold (TVent). Measurements included plasma [H+], arterial carbon dioxide tension (PaCO2 ), total weak acid ([ATot]) as reflected by total protein, and the strong-ion difference ([SID]). The transition from rest to exercise in both groups resulted in a significant increase in [H+] at 70% TVentversus rest and at 110% TVent versus both rest and 70% TVent. No significant between-group differences were observed for [H+] at rest or in response to exercise. At rest in the LP, [ATot] and PaCO2 were significantly lower (acts to decrease [H+]) compared with the FP. This effect was offset by a reduction in [SID] (acts to increase [H+]). After the transition from rest to exercise, significantly lower [ATot] during the LP was again observed. Although the [SID] and PaCO2 were not significantly different between groups, trends for changes in these two variables were similar to changes in the resting state. In conclusion, mechanisms regulating [H+] exhibit phase-related differences to ensure [H+] is relatively constant regardless of progesterone-mediated ventilatory changes during the LP.


2019 ◽  
Vol 33 (S1) ◽  
Author(s):  
Christian Damsgaard ◽  
Monica McGrath ◽  
Chris M. Wood ◽  
Jeffrey G. Richards ◽  
Colin J. Brauner

2007 ◽  
Vol 177 (6) ◽  
pp. 597-608 ◽  
Author(s):  
Josi R. Taylor ◽  
Jonathan M. Whittamore ◽  
Rod W. Wilson ◽  
Martin Grosell

2015 ◽  
Author(s):  
Muhammad Yousuf Ali ◽  
Ana Pavasovic ◽  
Peter B Mather ◽  
Peter J Prentis

Osmoregulation and systemic acid-base balance in decapod crustaceans are largely controlled by a set of transport-related enzymes including carbonic anhydrase (CA), Na + /K + -ATPase (NKA) and V-type- H + -ATPase (HAT). Variable pH levels and changes in osmotic pressure can have a significant impact on the physiology and behaviour of crustaceans. Therefore, it is crucial to understand the mechanisms via which an animal can maintain its internal pH balance and regulate the movement of ions into and out of its cells. Here, we examined expression patterns of the cytoplasmic (CAc) and membrane-associated form (CAg) of CA, NKA α subunit and HAT subunit a in gills of the freshwater crayfish Cherax quadricarinatus. Expression levels of the genes were measured at three pH levels, pH 6.2, 7.2 (control) and 8.2 over a 24 hour period. All genes showed significant differences in expression levels, either among pH treatments or over time. Expression levels of CAc were significantly increased at low pH and decreased at high pH conditions 24 h after transfer to these treatments. Expression increased in low pH after 12 h, and reached their maximum level by 24 h. The membrane-associated form CAg showed changes in expression levels more quickly than CAc. Expression increased for CAg at 6 h post transfer at both low and high pH conditions, but expression remained elevated only at low pH (6.2) at the end of the experiment. Expression of CqNKA significantly increased at 6 h after transfer to pH 6.2 and remained elevated up to 24 h. Expression for HAT and NKA showed similar patterns, where expression significantly increased 6 h post transfer to the low pH conditions and remained significantly elevated throughout the experiment. The only difference in expression between the two genes was that HAT expression decreased significantly 24 h post transfer to high pH conditions. Overall, our data suggest that CAc, CAg, NKA and HAT gene expression is induced at low pH conditions in freshwater crayfish. Further research should examine the physiological underpinnings of these changes in expression to better understand systemic acid/base balance in freshwater crayfish.


1961 ◽  
Vol 201 (6) ◽  
pp. 980-986 ◽  
Author(s):  
Hisato Yoshimura ◽  
Masateru Yata ◽  
Minoru Yuasa ◽  
Robert A. Wolbach

Renal mechanisms for the maintenance of acid-base balance were studied in the normal bullfrog, during metabolic and respiratory acidosis, and after carbonic anhydrase inhibition. Following intravenous administration of 0.3–12 mmole HCl/ kg, as 0.1 n HCl, urinary pH (initially pH 6.3–7.7) did not change significantly. However, urinary ammonia excretion increased more than twofold, and within 3–5 days the cumulative increase was equivalent to the acid load given. Despite the increased ammonia excretion, chloride excretion did not increase after acid loading. In both normal and acidotic bullfrogs ammonia excretion was correlated with an increase in urinary pH. Respiratory acidosis in the small frog, Rana limnocharis, produced by exposure to 6.4% CO2 in air, induced neither urinary acidification nor increased ammonia excretion; both urinary sodium and bicarbonate excretion increased. When renal carbonic anhydrase was inhibited by acetazoleamide injection, urine flow, sodium excretion, and bicarbonate excretion increased markedly, urinary pH increased slightly, and urinary ammonia excretion remained unchanged. These renal responses to acidosis are compared with those of the acidotic dog.


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