Influence of anaesthetics on the movement of the mobile charges in the algal cell membrane of Valonia utricularis

A method is described for the simultaneous determination of rapid changes of the cell turgor pressure (hydrostatic pressure) in algal cells (cell size must be at least 3 mm in diameter), and of the net volume flow across the cell membrane arising after a change of the cell turgor pressure or of the osmotic pressure in the outside medium. On the basis of the equations of irreversible thermodynamics it is possible to calculate the hydraulic conductivity of the cell membrane from these measurements, as it is theoretically shown.The hydraulic conductivities of the marine alga Valonia utricularis determined in two independent ways (by osmotic and hydrostatic experiments) are equal. For exosmosis, Lpex (hydrostatic) and Lpex (osmotic) amounted to (9,6 ± 1,0) ·10-7 and (9,8 ± 1,9) · 10-7 respectively cm · sec-1 · atm-1, and for endomosis, Lpen (hydrostatic) was (9,4 ± 1,1) ·10-7 cm · sec-1 · atm-1.A polarity in the water movement across the cell membranes as discussed in the literature could not be found for Valonia utricularis.

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Inhibitory mechanisms of Acacia mearnsii extracts on the growth of Microcystis aeruginosa

Water Science & Technology ◽

10.2166/wst.2015.038 ◽

2015 ◽

Vol 71 (6) ◽

pp. 856-861 ◽

Cited By ~ 4

Author(s):

Zhibin Liu ◽

Lirong Zhou ◽

Dandan Liu ◽

Qiyu Zhu ◽

Wenqing Chen

Keyword(s):

Cell Membrane ◽

Microcystis Aeruginosa ◽

Plant Extract ◽

Algal Cell ◽

Common Species ◽

Cyanobacterial Blooms ◽

Cell Membrane Permeability ◽

Acacia Mearnsii ◽

Inhibitory Mechanisms

Our previous work revealed that Acacia mearnsii extract can inhibit the growth of Microcystis aeruginosa, the common species forming toxic cyanobacterial blooms in eutrophic freshwater. In the present study, we demonstrated that this plant extract can significantly increase cell membrane permeability and Ca2+/Mg2+-ATPase activity on the membrane. Long-term exposure to concentrations of 20 ppm A. mearnsii extract led to algal cell membrane leakage or even lysis. Comparison of expression of three photosynthesis-related genes (rbcL, psaB and psbD) in M. aeruginosa with and without plant extract treatment revealed that their expression was remarkably reduced in the presence of the extract. Down-regulation of photosynthesis-related genes could indicate the inhibition of the photosynthetic process. Thus, our results suggested that both photosynthetic systems and membranes of M. aeruginosa are potentially damaged by A. mearnsii extract.

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Effect of alkaline earth ions on the movement of mobile charges in Valonia utricularis

Biochimica et Biophysica Acta (BBA) - Biomembranes ◽

10.1016/0005-2736(88)90040-5 ◽

1988 ◽

Vol 939 (1) ◽

pp. 1-7 ◽

Cited By ~ 5

Author(s):

L. Walter ◽

K.-H. Büchner ◽

U. Zimmermann

Keyword(s):

Alkaline Earth ◽

Valonia Utricularis ◽

Mobile Charges

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The Mechanism Insight Into the Inhibitory Effect of Artemisinin Sustained-release Inhibitors With Different Particle Sizes on Microcystis aeruginosa

10.21203/rs.3.rs-636883/v1 ◽

2021 ◽

Author(s):

Zhiyun Jiang ◽

lixiao Ni ◽

Xianglan Li ◽

Chu Xu ◽

Xuqing Chen ◽

...

Keyword(s):

Cell Membrane ◽

Sustained Release ◽

Chlorophyll A ◽

Microcystis Aeruginosa ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Algal Cell ◽

Inhibitory Effect ◽

Inhibitory Mechanism ◽

Irreversible Damage

Abstract Environment-friendly algaecides based on allelopathy have been widely used to control harmful algal blooms. In this research, micro nano scale artemisinin sustained-release algal inhibitor was prepared, the optimal preparation conditions were explored and the inhibitory mechanism of artemisinin algaecides was perfected. The results showed that when the particle size of artemisinin sustained-release microspheres (ASMs) was 2/10000 of artemisinin sustained-release granules (ASGs), the inhibitory effect was more remarkable. The optimal concentration of ASMs was 0.2 g L-1, and the inhibitory effect reached 99% on the 10th day; The algae density and chlorophyll-a both showed a downward trend, indicating that ASGs and ASMs could promote the degradation of chlorophyll-a; The inhibition rate of ASGs was faster than that of ASMs on the 4th day, and the inhibitory effect of ASMs was more significant after the 5th day. The activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) increased rapidly at first and then decreased, which indicated that ASGs and ASMs caused oxidative damage to Microcystis aeruginosa (M. aeruginosa) and inhibited the activity of antioxidant enzymes. Furthermore, the content of the oxygen free radical (O2-) and malondialdehyde (MDA) continued to rise after the 5th day, the protein, nucleic acid and conductivity in the culture medium increased. These results showed that lipid peroxidation occurred in the algal cell membrane, and the permeability of the membrane increased. In summary, the ASMs had significant continuous inhibitory effect while the ASGs had better short-term effect. The main inhibitory mechanism of artemisinin algaecides is the irreversible damage of cell membrane.

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Sarcolemmal permeability changes during early myocardial anoxia

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084089 ◽

1978 ◽

Vol 36 (2) ◽

pp. 642-643

Author(s):

M. Ashraf ◽

L. Landa ◽

L. Nimmo ◽

C. M. Bloor

Keyword(s):

Cell Membrane ◽

Membrane Permeability ◽

Coronary Artery Occlusion ◽

Artery Occlusion ◽

Cell Membrane Permeability ◽

Enzyme Release ◽

Sprague Dawley ◽

Sprague Dawley Rats ◽

Sarcolemmal Permeability ◽

Membrane Changes

Following coronary artery occlusion, the myocardial cells lose intracellular enzymes that appear in the serum 3 hrs later. By this time the cells in the ischemic zone have already undergone irreversible changes, and the cell membrane permeability is variably altered in the ischemic cells. At certain stages or intervals the cell membrane changes, allowing release of cytoplasmic enzymes. To correlate the changes in cell membrane permeability with the enzyme release, we used colloidal lanthanum (La+++) as a histological permeability marker in the isolated perfused hearts. The hearts removed from sprague-Dawley rats were perfused with standard Krebs-Henseleit medium gassed with 95% O2 + 5% CO2. The hypoxic medium contained mannitol instead of dextrose and was bubbled with 95% N2 + 5% CO2. The final osmolarity of the medium was 295 M osmol, pH 7. 4.

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Flagellar Attachment in Selected Trypanosomes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072927 ◽

1973 ◽

Vol 31 ◽

pp. 496-497

Author(s):

J. J. Paulin

Keyword(s):

Cell Membrane ◽

Lateral Surface ◽

The Body ◽

Flagellar Pocket ◽

Integral Component ◽

Free Flagellum ◽

Flagellar Axoneme

Movement in epimastigote and trypomastigote stages of trypanosomes is accomplished by planar sinusoidal beating of the anteriorly directed flagellum and associated undulating membrane. The flagellum emerges from a bottle-shaped depression, the flagellar pocket, opening on the lateral surface of the cell. The limiting cell membrane envelopes not only the body of the trypanosome but is continuous with and insheathes the flagellar axoneme forming the undulating membrane. In some species a paraxial rod parallels the axoneme from its point of emergence at the flagellar pocket and is an integral component of the undulating membrane. A portion of the flagellum may extend beyond the anterior apex of the cell as a free flagellum; the length is variable in different species of trypanosomes.

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Trophoblast Cell Membrane Interactions at Implantation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100068540 ◽

1970 ◽

Vol 28 ◽

pp. 310-311

Author(s):

A. C. Enders

Keyword(s):

Epithelial Cells ◽

Cell Membrane ◽

Membrane Fusion ◽

Trophoblast Cell ◽

Membrane Interactions ◽

Uterine Epithelial Cells ◽

Functional Complex ◽

Cytotrophoblast Cells ◽

Complex Relationships ◽

Syncytial Trophoblast

The alteration in membrane relationships seen at implantation include 1) interaction between cytotrophoblast cells to form syncytial trophoblast and addition to the syncytium by subsequent fusion of cytotrophoblast cells, 2) formation of a wide variety of functional complex relationships by trophoblast with uterine epithelial cells in the process of invasion of the endometrium, and 3) in the case of the rabbit, fusion of some uterine epithelial cells with the trophoblast.Formation of syncytium is apparently a membrane fusion phenomenon in which rapid confluence of cytoplasm often results in isolation of residual membrane within masses of syncytial trophoblast. Often the last areas of membrane to disappear are those including a desmosome where the cell membranes are apparently held apart from fusion.

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