In vivo effects of radioactive properties of Tl-201 on human carbonic anhydrase activity

2017 ◽  
Author(s):  
Ali Sahin ◽  
Murat Senturk
Keyword(s):  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Activity ◽  
Human Carbonic Anhydrase ◽  
In Vivo Effects

scholarly journals The Carbonic Anhydrase Inhibitor Ethoxzolamide Inhibits the Mycobacterium tuberculosis PhoPR Regulon and Esx-1 Secretion and Attenuates Virulence

2015 ◽  
Vol 59 (8) ◽  
pp. 4436-4445 ◽  
Author(s):  
Benjamin K. Johnson ◽  
Christopher J. Colvin ◽  
David B. Needle ◽  
Felix Mba Medie ◽  
Patricia A. DiGiuseppe Champion ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Carbonic Anhydrase ◽  
Regulatory System ◽  
Carbonic Anhydrase Activity ◽  
Carbonic Anhydrase Inhibitor ◽  
Fluorescent Reporter ◽  
Content Type ◽  
Pathogen Virulence ◽  
Mutant Phenotypes

ABSTRACTMycobacterium tuberculosismust sense and adapt to host environmental cues to establish and maintain an infection. The two-component regulatory system PhoPR plays a central role in sensing and responding to acidic pH within the macrophage and is required forM. tuberculosisintracellular replication and growthin vivo. Therefore, the isolation of compounds that inhibit PhoPR-dependent adaptation may identify new antivirulence therapies to treat tuberculosis. Here, we report that the carbonic anhydrase inhibitor ethoxzolamide inhibits the PhoPR regulon and reduces pathogen virulence. We show that treatment ofM. tuberculosiswith ethoxzolamide recapitulatesphoPRmutant phenotypes, including downregulation of the core PhoPR regulon, altered accumulation of virulence-associated lipids, and inhibition of Esx-1 protein secretion. Quantitative single-cell imaging of a PhoPR-dependent fluorescent reporter strain demonstrates that ethoxzolamide inhibits PhoPR-regulated genes in infected macrophages and mouse lungs. Moreover, ethoxzolamide reducesM. tuberculosisgrowth in both macrophages and infected mice. Ethoxzolamide inhibitsM. tuberculosiscarbonic anhydrase activity, supporting a previously unrecognized link between carbonic anhydrase activity and PhoPR signaling. We propose that ethoxzolamide may be pursued as a new class of antivirulence therapy that functions by modulating expression of the PhoPR regulon and Esx-1-dependent virulence.

scholarly journals Effect of NaHS on carbonic anhydrase activity of human erythrocyte

2016 ◽  
Vol 7 (3) ◽  
pp. 23-27 ◽  
Author(s):  
Abhijit Bhakta ◽  
Maitreyi Bandyopadhyay ◽  
Sayantan Dasgupta ◽  
Santanu Sen ◽  
Arun Kumar ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Normal Saline ◽  
Carbonic Anhydrase Activity ◽  
Experimental Models ◽  
Test Tube ◽  
Dependent Manner ◽  
Carbonic Anhydrases ◽  
Medical Sciences ◽  
First Time

Background: In contrast to its role as poison, hydrogen sulfide (H2S) is recently considered as a gaso-transmitter which mediates important physiologic functions in humans. Evidence is accumulating to demonstrate that inhibitors of H2S production or therapeutic H2S donor compounds exert significant effects in various experimental models. Carbonic anhydrases (CA) are a group of zinc-containing metalloenzymes that catalyse the reversible hydration of carbon dioxide. CAs activity in erythrocytes (CAI and CAII) has recently been observed to be associated with various pathological conditions especially in diabetes mellitus, hypertension and lipid disorders. Alteration of this enzyme activity has been reported by the effect of advanced glycation end products methylglyoxal and reduced glutathione.   Aims and Objectives: As H2S, being a mediator of many physiological functions and synthesized in vivo, may affect functions of many intracellular proteins like carbonic anhydrase, the objective of this study is to find out if there is any change in the carbonic anhydrase activity under the effect of H2S- donor NaHS in dose dependant manner using RBC model in vitro.Materials and Methods: Blood sample was collected from forty (40) numbers of healthy volunteers of 18-40 years of in heparin containing vials and packed cells were prepared immediately by centrifugation  The packed erythrocytes were washed three times with normal saline and  diluted (1:10) with the normal saline. One ml each of diluted packed cells was taken in eight test tubes. Serial dilutions of NaHS (1to 250 µMol/L) was added to all the test tubes except for the first test tube where only normal saline was added and   incubated at room temperature for one hour. Haemolysates was prepared from the erythrocytes with equal volume of distilled water in each tube and the CA activity was determined in the haemolysates using standardized method.Results: There is significant increase of CA activity in dose dependent manner under the effect of NaHS and also compared to the activity of hemolysate prepared without NaHS.  Conclusions:Our study for the first time demonstrated that the Carbonic Anhydrase activity of erythrocytes is significantly increases by the effect of NaHS and this study reveals some important biological role of H2S and carbonic anhydrase.Asian Journal of Medical Sciences Vol. 7(3) 2016 23-27

In vivo Demonstration of Renal Carbonic Anhydrase Activity in the Fetal Lamb

Neonatology ◽  
1978 ◽  
Vol 34 (5-6) ◽  
pp. 253-258 ◽  
Author(s):  
Jean E. Robillard ◽  
Christine Sessions ◽  
Fred G. Smith, jr.
Keyword(s):  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Activity ◽  
Fetal Lamb ◽  
Renal Carbonic Anhydrase

Direct evaluation of the permeability of the rat proximal convoluted tubule to CO2

1982 ◽  
Vol 242 (5) ◽  
pp. F470-F476
Author(s):  
M. S. Lucci ◽  
L. R. Pucacco ◽  
N. W. Carter ◽  
T. D. DuBose
Keyword(s):  
Carbonic Anhydrase ◽  
Proximal Tubule ◽  
Carbonic Acid ◽  
Carbonic Anhydrase Activity ◽  
Proximal Convoluted Tubule ◽  
Direct Evaluation ◽  
Carbon Dioxide Gas ◽  
Peritubular Capillaries ◽  
Rat Proximal Tubule

Conflicting data exist regarding the ability of the rat proximal convoluted tubule to maintain a transepithelial gradient for CO2 and the effects of carbonic anhydrase on CO2 permeability. The present in vivo microperfusion experiments were designed to assess the ability of the rat proximal tubule to sustain a CO2 gradient between tubule lumen and peritubular blood. Tubules were perfused at rates ranging from 10 to 100 nl/min with isotonic sodium chloride containing no CO2. Peritubular capillary and intraluminal PCO2 was measured during microperfusion with PCO2 microelectrodes to allow determination of the transepithelial CO2 gradient. The mean PCO2 measured in peritubular capillaries of control rats was 60.6 +/- 1.9 mmHg. Since the perfusion solution initially contained no CO2, a gradient of 60 mmHg was imposed across the tubule epithelium. Intraluminal PCO2 rapidly approached that of the surrounding capillaries. At a tubule perfusion rate of 20 nl/min, the gradient between lumen and blood decreased to 0.9 mmHg, a value not significantly greater than zero. The calculated CO2 permeability coefficient (KCO2) was 3.69 X 10(-5) cm2/s. Addition of either 10(-4) M acetazolamide or benzolamide did not prolong the rapid dissipation of the imposed CO2 gradient. The KCO2 during carbonic anhydrase inhibition was not significantly different from control values. It is concluded that the rat proximal tubule does not present a physiologically significant diffusion barrier to CO2 either in the presence or absence of carbonic anhydrase activity. The previously demonstrated acid disequilibrium pH in the proximal tubule during inhibition of carbonic anhydrase represents an intraluminal accumulation of carbonic acid rather than of carbon dioxide gas.

Postcapillary changes in blood pH in vivo during carbonic anhydrase inhibition

1977 ◽  
Vol 43 (4) ◽  
pp. 582-590 ◽  
Author(s):  
E. D. Crandall ◽  
A. Bidani ◽  
R. E. Forster
Keyword(s):  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Activity ◽  
Stopped Flow ◽  
Arterial Blood ◽  
Blood Ph ◽  
Pulmonary Capillary ◽  
Carbonic Anhydrase Inhibition ◽  
Glass Ph Electrode ◽  
Electrode Chamber

A rapidly responding stopped-flow glass pH electrode apparatus was used to investigate pH changes in blood in vivo after it exits from an exchange capillary. Arterial blood was drawn from anesthetized animals through the apparatus. Temperature and pH of the blood in the electrode chamber were continuously recorded, both during withdrawal and after flow was stopped. Blood pH did not change after stopping flow in control experiments. When benzolamide (2 mg/kg) was given to inhibit carbonic anhydrase activity available to plasma (e.g., due to lysis) while having less effect on intracellular activity, pH increased 0.02–0.04 (t1/2 approximately 8 s) after stopping flow. Administration of acetazolamide (50 mg/kg) resulted in pH decreasing 0.07–0.10 (t1/2 approximately 15 s) after stopping flow. Ventilation for 1 min with N2 resulted in an increased rise in pH for the benzolamide-treated animals but a decreased fall in pH for the acetazolamide-treated animals. These shifts in arterial blood pH after gas exchange are largely due to disequilibrium of [H+] between red cells and plasma at the end of the pulmonary capillary.

scholarly journals In Vitro and in Vivo Effects of Dantrolene on Carbonic Anhydrase Enzyme Activities

2004 ◽  
Vol 27 (5) ◽  
pp. 613-616 ◽  
Author(s):  
İlhami Gülçin ◽  
Şükrü Beydemir ◽  
Mehmet Emin Büyükokuroğlu
Keyword(s):  
Carbonic Anhydrase ◽  
Enzyme Activities ◽  
In Vivo Effects ◽  
Carbonic Anhydrase Enzyme

scholarly journals Functional involvement of carbonic anhydrase in calcium transport of the chick chorioallantoic membrane

1978 ◽  
Vol 176 (1) ◽  
pp. 67-74 ◽  
Author(s):  
R S Tuan ◽  
J Zrike
Keyword(s):  
Carbonic Anhydrase ◽  
Chorioallantoic Membrane ◽  
Carbonic Anhydrase Activity ◽  
Calcium Deposition ◽  
Dependent Manner ◽  
Transport Activity ◽  
In Ovo ◽  
Chick Chorioallantoic Membrane ◽  
Age Dependent

Carbonic anhydrase activity was demonstrated in the chick-embryonic chorioallantoic membrane and was correlated with the Ca2+-transport activity of the membrane. It is inhibited by sulphonamides and is expressed in the chorioallantoic membrane in an age-dependent fashion during embryonic development. Ca2+ uptake by the chorioallantoic membrane in vivo also increases in a similar age-dependent manner. The temporal increase in these activities is coincident with calcium deposition in the embryonic skeleton. Incubation of the chorioallantoic membrane in ovo with sulphonamides specifically inhibits both the carbonic anhydrase and the Ca2+ uptake activities of the membrane in vivo. Enzyme histochemistry revealed the carbonic anhydrase activity is localized in the Ca2+-transporting ectodermal cells of the chorioallantoic membrane. These results, taken together, indicate that carbonic anhydrase may be functionally important in the Ca2+-transport activity of the chorioallantoic membrane.

Sign in / Sign up

Export Citation Format

Share Document