Plasma membrane, permeability

The occurrence and timing of effects on intracellular ionized calcium concentration, lysosomal mass, oxidative stress or plasma membrane permeability frequently provide additional information indicative of mechanism of toxicity (Table 14.5). 

Mechanism of Action Anantibioticthatinterfereswith plasma membrane permeability and inhibits bacterial cell wall synthesis in susceptible bacteria. TherapeaticEffect Bacteriostatic. 

Direct or indirect effects of metals on the alteration of the plasma membrane permeability, which can lead to leakage of ions and other solutes... 

An important harmful effect of metals at the cellular level is the alteration of the plasma membrane permeability, leading to leakage of ions like potassium and other solutes (Passow and Rothstein, 1960 Wainwright and Woolhouse, 1978 De Filippis, 1979 De Vos et al., 1988, 1991). After supply of copper ions Ohsumi et al. (1988) demonstrated for yeast cells and De Vos et al. (1989) for root cells of Silene cucubalus that the permeability barrier (controlled by means of potassium leakage) of the plasma membrane was almost immediately lost. Oshumi et al. (1988) also reported a quick release of amino acids, especially glutamate and aspartate. After McBrien and Hassall (1965) and Overnell (1975), who studied potassium release from algal cells, the increased permeability of the plasma membrane may be considered to constitute the primary toxic effect of copper. 

Comparison of four CPPs— penetratin (5), Tat (6), transportan (12), and model amphipathic peptide (MAP) (13)— revealed that a model peptide cargo was most efficiently delivered into Bowes melanoma cells by MAP and transportan peptides. As judged by energy transfer experiments (31), the intracellular concentration of a cargo peptide delivered into cells by penetratin or Tat remained three- to fourfold lower compared with transportan- and MAP-mediated delivery. On the other hand, transportan and MAP were more noxious to cells and increased the plasma membrane permeability at lower concentrations. Import of penetratin sequences by the melanoma-derived SKMel-37 cells was in turn three- to fourfold more efficient than uptake of MTS-sequences as measured by fluorescence correlation spectroscopy in living cells and by FACS analysis (32). 

In fungi, some resistance mechanisms may be similar to those of bacteria, for example, the enzymatic degradation of sorbic acid to pentadine by certain fungal species (Samson et al., 1995). Resistance development is attributed to (1) decreased plasma membrane permeability to diffusional preservative influx (Warth, 1989), (2) active extrusion of organic acid anion... 

When an established cell line is studied the cells can be cultured at standard conditions and plated on cover slips. Cells are permeabilized in situ by either of two methods. Both methods are suited to make the plasma membrane permeable to antibodies while leaving the NE and the NPC intact. 

Microinjection is a tool to overcome the plasma membrane permeability barrier to the introduction of charged molecules, polypeptides, or DNA plasmids into cells. In essence, microinjection treats the cell as the test tube and uses a microinjection capillary needle as the pipette to add small volumes of solution to the cytoplasm or nucleus. The approach has major advantages (i) the technique is highly synchronous with a few hundred cells being injected over 10-20 minutes, (ii) intracellular environment and cell morphology is preserved, (iii) the reaction vessel is small, that is, the size of a cell, and correspondingly reagent dilution is confined to the... 

Umebayashi, Y Miyamoto, Y Wakita, M. Kobayashi, A. Nishisaka, T. Elevation of plasma membrane permeability on laser irradiation of extracellular latex particles. J. Biochem. 2003,134, 219-224. 

G.J. (2005) Elevation of plasma membrane permeability by laser irradiation of selectively bound nanopartides. Biomedical Optics, 10,... 

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