Carbonic Anhydrase and Heavy Metals

Carbonic anhydrase (CA; EC 4.2.1.1) is a zinc metalloenzyme catalysing the reversible hydration of CO2 to produce H+ and HCO3−. Its activity is virtually ubiquitous in nature. The review focuses on one interesting but less investigated aspect of the biochemistry of this metalloenzyme, encompassing several areas of interest from human health to environmental science: the relationships between carbonic anhydrase and heavy metals

Cell Volume Regulation and Apoptotic Volume Decrease in Rat Distal Colon Superficial Enterocytes

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Cell Volume regulation in eel intestine

In this review the authors summarize the present insight about cell volume regulation in the European eel (Anguilla anguilla), highlighting findings on the intestinal epithelium, which serves as one of the main osmoregulatory organs in the fish. This tissue is a useful model system for functional studies of epithelia that perform near-isosmotic fluid absorption and has specifically been used as a physiological model for the study of cell volume regulation in epitheli

Colorimetric method and apparatus for measuring the toxic effect of environmental pollutants on hemoglobin

Method for measuring the toxicity of environmental matrices characterized in that it uses the oxidation of the iron present in the hemoglobin molecule as indicator of toxicity of said environmental matrices according to the steps of adding hemoglobin in an aqueous sample of environmental matrix, adding potassium thiocyanate, quantifying the oxidation state of thè iron present in the hemoglobin molecule by means of colorimetric analysis of the sample

Mercury induced haemocyte alterations in the terrestrial snail Cantareus apertus as novel biomarker

The aim of the present work was to study the response of a suite of cellular and biochemical markers in the terrestrial snail Cantareus apertus exposed to mercury in view of future use as sensitive tool suitable formercury polluted soil monitoring and assessment. Besides standardized biomarkers (metallothionein, acetylcholinesterase, and lysosomal membrane stability) novel cellular biomarkers on haemolymph cells were analyzed, including changes in the spread cells/round cells ratio and haemocyte morphometric alterations. The animals were exposed for 14 days to Lactuca sativa soaked for 1 h in HgCl2 solutions (0.5 e 1 μM). The temporal dynamics of the responses were assessed by measurements at 3, 7 and 14 days. Following exposure to HgCl2 a significant alteration in the relative frequencies of round cells and spread cellswas evident, with a time and dose-dependent increase of the frequencies of round cells with respect to spread cells. These changes were accompanied by cellular morphometric alterations. Concomitantly, a high correspondence between these cellular responses and metallothionein tissutal concentration, lysosomal membrane stability and inhibition of AChE was evident. The study highlights the usefulness of the terrestrial snail C. apertus as bioindicator organism for mercury pollution biomonitoring and, in particular, the use of haemocyte alterations as a suitable biomarker of pollutant effect to be included in a multibiomarker strategy

A novel physiological role for carbonic anhydrase in animals: involvement in the lysosomal response to cadmium exposure in mussel digestive gland

Carbonic anhydrase (CA) is a ubiquitous metalloenzyme involved in a number of physiological processes including respiration, pH homeostasis, electrolyte transport, calcification, biosynthetic reactions. The aim of this work was to explore a novel functional role of CA in animals: its involvement in the lysosomal system response to metal exposure. Mytilus galloprovincialis digestive gland was used as experimental model. The in vivo exposure of mussels to CdCl2 was able to evoke the induction of digestive gland CA. This response was paralleled by the activation of the lysosomal compartment (proliferation and/or increase in size of lysosomes), as assessed on LysoSensor Green marked cells by confocal microscopy and spectrofluorimetric analysis. When mussels were in vivo exposed to acetazolamide, specific CA inhibitor, the acidification of the lysosomal compartment was prevented. Moreover, during the co-exposure to cadmium and acetazolamide, the cadmium induced activation of the lysosomal compartment was completely inhibited. In conclusion, our results demonstrated in vivo the physiological contribution of CA to the acidification of the lysosomal compartment in digestive gland and its involvement in the lysosomal activation following cadmium exposure. CA induction following cadmium exposure could physiologically sustain a prolonged increased requirement of H+ for supporting lysosomal acidification during lysosomal activation

The Complex Relationship between Metals and Carbonic Anhydrase: New Insights and Perspectives

Carbonic anhydrase is a ubiquitous metalloenzyme, which catalyzes the reversible hydration of CO2 to HCO3 and H+. Metals play a key role in the bioactivity of this metalloenzyme, although their relationships with CA have not been completely clarified to date. The aim of this review is to explore the complexity and multi-aspect nature of these relationships, since metals can be cofactors of CA, but also inhibitors of CA activity and modulators of CA expression. Moreover, this work analyzes new insights and perspectives that allow translating new advances in basic science on the interaction between CA and metals to applications in several fields of research, ranging from biotechnology to environmental sciences