Résumé
Snake venoms are toxic to a variety of cell types. However, the intracellular damages and the cell death fate induced by venom are unclear. In the present work, the action of the South American rattlesnake Crotalus durissus terrificus venom on CHO-K1 cell line was analyzed. The cells CHO-K1 were incubated with C. d. terrificus venom (10, 50 and 100g/ml) for 1 and 24 hours, and structural alterations of actin filaments, endoplasmic reticulum and nucleus were assessed using specific fluorescent probes and agarose gel electrophoresis for DNA fragmentation. Significant structural changes were observed in all analyzed structures. DNA fragmentation was detected suggesting that, at the concentrations used, the venom induced apoptosis.
Sujets)
Animaux , Mâle , Femelle , Cellules CHO , Réticulum endoplasmique , Venins de crotalidé , ApoptoseRésumé
The effects of Photodynamic Therapy using 2nd generation photosensitizers have been widely investigated aiming clinical application treatment of solid neoplasms. In this work, ultrastructure changes caused by the action of two 2nd generation photosensitizers and laser irradiation on CHO-K1 and HeLa (neoplastic) cells were analyzed by transmission electron microscopy. Aluminum phthalocyanine chloride, aluminum phthalocyanine tetrasulfonate chloride and radiation from a semiconductor laser at a fluency of 0.5 J/cm2 (Power=26 mW; lambda=.670 nm) were used. The results showed induction of apoptosis. Such alterations where observed in HeLa but not in CHO-K1 cells after Aluminum phthalocyanine tetrasulfonate chloride (AlPcS4, photodynamic treatment. The Aluminum phthalocyanine chloride (AlPc) photodynamic treatment induced necrosis on the neoplastic cell line, and cytoplasm and nuclear alterations on the normal cell line.
Sujets)
Humains , Femelle , Cricetinae , Photothérapie dynamique/méthodes , Lasers , Tumeurs du col de l'utérus/traitement médicamenteux , Ovaire/effets des médicaments et des substances chimiques , Radiosensibilisants/pharmacologie , Apoptose/effets des médicaments et des substances chimiques , Apoptose/physiologie , Apoptose/effets des radiations , Cellules CHO , Cytoplasme/effets des médicaments et des substances chimiques , Cytoplasme/effets des radiations , Cytoplasme/ultrastructure , Composés organométalliques/pharmacologie , Stimulation lumineuse/instrumentation , Stimulation lumineuse/méthodes , Cellules HeLa , Indoles/pharmacologie , Lumière , Microscopie électronique , Mitochondries/effets des médicaments et des substances chimiques , Mitochondries/effets des radiations , Mitochondries/ultrastructure , Nécrose , Tumeurs du col de l'utérus/ultrastructure , Noyau de la cellule/effets des médicaments et des substances chimiques , Noyau de la cellule/effets des radiations , Noyau de la cellule/ultrastructure , Ovaire/ultrastructureRésumé
Chicken leukocytes were separated from blood on a Percoll cushion following adherence on coverslips, resulting in a coculture of thrombocytes and monocytes. This system was characterized by light microscopy, scanning and transmission electron microscopy, by lectin binding and actin localization in thrombocytes. During the first 24 hours nuclear condensation, cytoplasmic shrinkage, detachment and death of thrombocytes were observed. In contrast, monocytes gradually increased their spreading capacity, specially after thrombocyte detachment from the coverslips. During culture, a large number of fucose and beta-galactose residues were expressed on the surface of thrombocytes, revealed by the lectins Ulex europaeus I and Arachis hypogaea, respectively. Labeling of the monocyte surface with several lectins also increased with the cultivation time. Thrombocytes showed the formation of a net with actin involvement