Histochemical and biochemical studies of carbonic anhydrase activity in the opercular epithelium of the euryhaline teleost,Fundulus heteroclitus

1983 ◽  
Vol 166 (1) ◽  
pp. 19-39 ◽  
Author(s):  
Eric R. Lacy
Keyword(s):  
Carbonic Anhydrase ◽  
Fundulus Heteroclitus ◽  
Carbonic Anhydrase Activity ◽  
Biochemical Studies ◽  
Euryhaline Teleost

Carbonic Anhydrase Activity in Early Developing Chick Embryos

Development ◽  
1962 ◽  
Vol 10 (2) ◽  
pp. 191-201
Author(s):  
Thomas H. Shepard
Keyword(s):  
Carbonic Anhydrase ◽  
Sexual Differentiation ◽  
Cellular Differentiation ◽  
Fundulus Heteroclitus ◽  
Culture Media ◽  
Neural Tissue ◽  
Carbonic Anhydrase Activity ◽  
Chick Embryos ◽  
Co2 Gas ◽  
Minute Period

Changes in tension of environmental CO2 gas have been shown to affect cellular differentiation. In the presence of increased partial pressure of dissolved CO2(pCO2) Loomis (1957) has demonstrated an increase in sexual differentiation of hydra and Flickinger (1958) has caused explanted frog ectoderm to differentiate into neural tissue. Loomis was able to show that the substance which stimulates sexual differentiation in crowded cultures of Hydra littoralis is dissolved CO2 gas. Flickinger could produce a definite increase of neural tissue induction by bubbling CO2 gas through the culture media for a 10–20-minute period. Trinkaus & Drake (1959) have reported an analysis of the stimulating effect of PCO2 on development of the embryo of Fundulus heteroclitus. For these reasons it seemed important to study an enzyme which utilizes CO2 as a substrate. The appearance of carbonic anhydrase activity in early developing embryos which are producing CO2 might lead to a reduced CO2 tension (H2O+CO2⇆H2CO3).

1123: Renal Oxalate Transport Depends on Local Carbonic Anhydrase Activity in the Proximal Tubule

2004 ◽  
Vol 171 (4S) ◽  
pp. 296-296
Author(s):  
Michael Straub ◽  
Joséphine Befolo-Elo ◽  
Richard E Hautmann ◽  
Edgar Braendle
Keyword(s):  
Carbonic Anhydrase ◽  
Proximal Tubule ◽  
Carbonic Anhydrase Activity ◽  
Oxalate Transport

RENAL CARBONIC ANHYDRASE IN PREMATURE AND MATURE INFANTS

PEDIATRICS ◽  
1951 ◽  
Vol 7 (2) ◽  
pp. 182-185
Author(s):  
RICHARD DAY ◽  
JANE FRANKLIN
Keyword(s):  
Carbonic Anhydrase ◽  
Premature Infants ◽  
Carbonic Anhydrase Activity ◽  
Renal Carbonic Anhydrase

The carbonic anhydrase activity in the kidneys of premature infants was studied because it was thought that if the renal enzyme is as deficient as that in the blood, inefficiency in acidification of urine might result. In contrast with the blood, postmortem specimens of kidneys of premature infants were found to exhibit carbonic anhydrase activity similar to that found in the case of kidneys from older infants and adults.

The Effect of Cholera Toxin on Choroid Plexus Carbonic Anhydrase Activity In Vitro

1980 ◽  
Vol 1 (4) ◽  
pp. 333-339
Author(s):  
Arthur M. Feldman ◽  
Mel H. Epstein ◽  
Fallon Maylack ◽  
Saul W. Brusilow
Keyword(s):  
Carbonic Anhydrase ◽  
Choroid Plexus ◽  
Cholera Toxin ◽  
Carbonic Anhydrase Activity

scholarly journals The Periplasmic α-Carbonic Anhydrase Activity of Helicobacter pylori Is Essential for Acid Acclimation

2005 ◽  
Vol 187 (2) ◽  
pp. 729-738 ◽  
Author(s):  
Elizabeth A. Marcus ◽  
Amiel P. Moshfegh ◽  
George Sachs ◽  
David R. Scott
Keyword(s):  
Helicobacter Pylori ◽  
Membrane Potential ◽  
Carbonic Anhydrase ◽  
Membrane Integrity ◽  
Carbonic Anhydrase Activity ◽  
Knockout Mutant ◽  
Inner Membrane ◽  
Acid Acclimation

ABSTRACT The role of the periplasmic α-carbonic anhydrase (α-CA) (HP1186) in acid acclimation of Helicobacter pylori was investigated. Urease and urea influx through UreI have been shown to be essential for gastric colonization and for acid survival in vitro. Intrabacterial urease generation of NH3 has a major role in regulation of periplasmic pH and inner membrane potential under acidic conditions, allowing adequate bioenergetics for survival and growth. Since α-CA catalyzes the conversion of CO2 to HCO3 −, the role of CO2 in periplasmic buffering was studied using an α-CA deletion mutant and the CA inhibitor acetazolamide. Western analysis confirmed that α-CA was bound to the inner membrane. Immunoblots and PCR confirmed the absence of the enzyme and the gene in the α-CA knockout. In the mutant or in the presence of acetazolamide, there was an ∼3 log10 decrease in acid survival. In acid, absence of α-CA activity decreased membrane integrity, as observed using membrane-permeant and -impermeant fluorescent DNA dyes. The increase in membrane potential and cytoplasmic buffering following urea addition to wild-type organisms in acid was absent in the α-CA knockout mutant and in the presence of acetazolamide, although UreI and urease remained fully functional. At low pH, the elevation of cytoplasmic and periplasmic pH with urea was abolished in the absence of α-CA activity. Hence, buffering of the periplasm to a pH consistent with viability depends not only on NH3 efflux from the cytoplasm but also on the conversion of CO2, produced by urease, to HCO3 − by the periplasmic α-CA.

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