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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Intracellular potassium activity in epithelial cells of frog fundic gastric mucosa.

Microelectrodes were used to measure membrane potential and intracellular potassium activity in surface epithelial cells (SEC) of frog (Rana esculenta) fundic gastric mucosa in vitro. Separate measurements were carried out by applying fine-tipped, single barrelled, KCl filled non-selective electrodes and liquid K+ -selective electrodes. Membrane potentials with respect to the mucosal and serosal surfaces, measured with non-selective electrodes, were -54.5 +/- 1.0 S.E mV (n = 59) and -73.0 +/- 1.1 S.E. mV (n = 59) respectively. The electrical potential difference referred to the mucosal surface, when measured with K+ -sensitive electrodes, was +21.2 +/- 0.8 S.E mV (n = 35), and intracellular K+ activity was 98.5 mmol/l. Assuming that intracellular and extracellular K+ activity coefficients are equal (gamma K = gamma K), the K+ concentration is 135.0 mmol/l. The K+ equilibrium potential, EK, was calculated as -90. mV i.e. more negative than both membrane potentials. This result indicates active potassium accumulation in the SEC and provides direct evidence of the presence of an active K+ pump in either both or in only one of the cell membrane

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