Cell disruption erythrocytes

In vitro cytotoxicity assays using isolated cells have been applied intermittently to cyanobacterial toxicity testing over several years." Cells investigated for suitability in cyanobacterial toxin assays include primary liver cells (hepatocytes) isolated from rodents and fish, established permanent mammalian cell lines, including hepatocytes, fibroblasts and cancerous cells, and erythrocytes. Earlier work suggested that extracts from toxic cyanobacteria disrupted cells of established lines and erythrocytes," but studies with purified microcystins revealed no alterations in structure or ion transport in fibroblasts or erythrocytes,... 

The principal toxicological effect observed upon overexposure to EGBE is the destruction of red blood cells (i.e., hemolysis). BAA, the predominant oxidative metabolite of EGBE, appears responsible for this hemolytic activity. It has been speculated that BAA may interact with red blood cell membranes disrupting erythrocyte osmotic balance, leading to cellular swelling, loss of deformability, and eventually... 

Mehorta and coworkers (1989) observed that isolated fractions of brain and heart cells from rats orally administered 0.5-10 mg endrin/kg showed significant inhibition of Ca+2 pump activity and decreased levels of calmodulin, indicating disruption of membrane Ca+2 transport mechanisms exogenous addition of calmodulin restored Ca+2-ATPase activity. In vitro exposure of rat brain synaptosomes and heart sarcoplasmic reticuli decreased total and calmodulin-stimulated calcium ATPase activity with greater inhibition in brain preparations (Mehorta et al. 1989). However, endrin showed no inhibitory effects on the calmodulin-sensitive calcium ATPase activity when incubated with human erythrocyte membranes (Janik and Wolf 1992). In vitro exposure of rat brain synaptosomes to endrin had no effect on the activities of adenylate cyclase or 3, 5 -cyclic phosphodiesterase, two enzymes associated with synaptic cyclic AMP metabolism (Kodavanti et al. 1988). 

Hemolysis is the leakage of hemoglobin into liquid such as plasma, and is due to disruption of the erythrocytes. Within the body, hemolysis maybe caused by some diseases or poisons, whereas hemolysis outside the body, as in artificial organs, is caused by physical or chemical factors. If erythrocytes are placed in water, hemolysis will occur as the cells rupture due to the difference in osmotic pressure between water and the intracellular liquid. Hemolysis in artificial organs and their accessories occurs due to a variety of physical factors, including turbulence, shear, and changes of pressure and velocity. It is difficult, however, to obtain any quantitative correlation between the rates of hemolysis and such physical factors. 

The finding that water-soluble flavonoids could exert their beneficial properties at the hydrophobic portion of the membrane was also observed in in vivo studies and in cells in culture. For example, erythrocytes obtained from animals fed a flavanol- and procyanidin-rich meal showed reduced susceptibility to free-radical-mediated hemolysis [Zhu et al., 2002]. Consistently, we demonstrated that procyanidin hexamers, which interact with membranes but would not be internalized, protected Caco-2 cells from AMVN- and bile-induced oxidation [Erlejman et al., 2006]. When liposomes were preincubated with a series of flavonoids with diverse hydrophobicity, not only hydrophobic flavonoids prevented AMVN-mediated lipid oxidation but also the more hydrophilic ones [Erlejman et al., 2004]. Similarly to what was previously found in liposomes, the protective effects of flavonoids against AMVN-supported oxidation was strongly associated with their capacity to prevent membrane disruption by detergents, supporting the hypothesis of a physical protection of membranes by preventing oxidants to reach fatty acids. 

Just I, Sehr P, Jung M et al. (1995) ADP-ribosyltransferase type A from turkey erythrocytes modifies octin at Arg-95 and Arg-372. In Biochemistry 34 326-33 Kiefer A, Lerner M, Sehr P et al. (1996) Depolymerization of F-octin by microinjection of ADP-ribosyloted skeletal muscle G-actin in PtK2 cells in the absence of the ADP-ribosylating toxin. In Med. Microbiol. Immunol. 184 175—80 Li G, Rungger-Brandle E, Just 1 etal. (1994) Effect of disruption of actin filaments by Clostridium botulinum C2 toxin on insulin secretion in HIT-T15 cells and pancreatic islets. In Mol. Biol. Cell 5 1199-213... 

Rabbit erythrocytes exposed to low concentrations of puromycin (7 x 10 " moll ) caused disruption of cell membrane indicating inhibition of protein synthesis by erythrocytes. Puromycin is shown to cause nephrosis in rats. It is a glomerular nephrotoxi-cant and is extensively used to study pathophysiology of glomerular nephritis and nephrotic syndrome. 

Hemolysis is defined as the disruption of the red cell membrane and results in the release of hemoglobin. Serum shows visual evidence of hemolysis when the hemoglobin concentration exceeds 200 ing/L. Slight hemolysis has little effect on most test values. Severe hemolysis causes a slight dilutional effect on those constituents present at a lower concentration in the erythrocytes than in plasma. However, a notable effect may be observed on those constituents that are present at a higher concentration in erythrocytes other than in plasma. Thus plasma activities or concentrations of aldolase, total acid phosphatase, lactate dehydrogenase, isocitrate dehydro-... 

Solasonine inhibited larval development and pupation in Earias insulana [644], inhibited elongation of letuce seed radicles [646], inhibited the infectivity of herpes simplex virus type 1 and was cytotoxic to Vero cell cultures [652]. Solasonine weakly inhibited mycelium development in the fungus Phoma medicaginis synergism was observed in combination with 290 [647]. Solasonine lysed Penicillium notatum-derived protoplasts and bovine erythrocytes [648] and weakly disrupted stigmasterol and ergosterol liposomes [649] in each case, 290 was considerably more active. The completely assigned H and 13C NMR spectra for 291 have been reported [642],... 

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