Résumé
CG 10-248 (3,4-dihydro-2,2-dimethyl-9-chloro-2H-naphtho[1,2b]pyran-5,6-dione; CG-NQ), a beta-lapachone analogue, modified the ultrastructure of rat hepatocytes, as demonstrated by light and electron microscopy. After 4 h incubation with 100 microM CG-NQ, the following effects were observed: (a) nuclear chromatin condensation; (b) chromatin fragmentation; (c) displacement of mitochondria, concentrated around the nucleus; (d) disruption or expansion of mitochondrial outer or inner membranes, respectively; (e) displacement and alteration of endoplasmic reticulum (rough and smooth); (f) decrease of microvilli; (g) blebbing of plasma membrane and production of apoptotic bodies formed by folding of plasma membrane fragments around mitochondria or peroxysomes; and (h) production of hydrogen peroxide. Expression of such effects varied according to hepatocyte samples and taken together strongly support an apoptotic action of CG-NQ dependent on reactive oxygen species.
Sujets)
Humains , Mâle , Apoptose/effets des médicaments et des substances chimiques , Hépatocytes/effets des médicaments et des substances chimiques , Naphtoquinones/pharmacologie , Naphtoquinones/toxicité , Apoptose/physiologie , Cellules cultivées , Chromatine/effets des médicaments et des substances chimiques , Chromatine/anatomopathologie , Prolongements cytoplasmiques/effets des médicaments et des substances chimiques , Prolongements cytoplasmiques/anatomopathologie , Prolongements cytoplasmiques/ultrastructure , Fragmentation de l'ADN/effets des médicaments et des substances chimiques , Fragmentation de l'ADN/physiologie , Hépatocytes/métabolisme , Hépatocytes/ultrastructure , Microscopie électronique , Membranes intracellulaires/effets des médicaments et des substances chimiques , Membranes intracellulaires/anatomopathologie , Membranes intracellulaires/ultrastructure , Microvillosités/effets des médicaments et des substances chimiques , Microvillosités/anatomopathologie , Microvillosités/ultrastructure , Mitochondries/effets des médicaments et des substances chimiques , Mitochondries/anatomopathologie , Mitochondries/ultrastructure , Peroxyde d'hydrogène/métabolisme , Rats , Rat Wistar , Réticulum endoplasmique/effets des médicaments et des substances chimiques , Réticulum endoplasmique/anatomopathologie , Réticulum endoplasmique/ultrastructureRésumé
Spinach leaves were studied by high resolution 13C-NMR spectroscopy. The spectra obtained, though highly complex, showed some distinct resonances assignable to carbons of lipids of the chloroplast membranes, thereby offering a novel way for studying the chloroplast membranes in situ.