ABSTRACT
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.
Subject(s)
Humans , Male , Apoptosis/drug effects , Hepatocytes/drug effects , Naphthoquinones/pharmacology , Naphthoquinones/toxicity , Apoptosis/physiology , Cells, Cultured , Chromatin/drug effects , Chromatin/pathology , Cell Surface Extensions/drug effects , Cell Surface Extensions/pathology , Cell Surface Extensions/ultrastructure , DNA Fragmentation/drug effects , DNA Fragmentation/physiology , Hepatocytes/metabolism , Hepatocytes/ultrastructure , Microscopy, Electron , Intracellular Membranes/drug effects , Intracellular Membranes/pathology , Intracellular Membranes/ultrastructure , Microvilli/drug effects , Microvilli/pathology , Microvilli/ultrastructure , Mitochondria/drug effects , Mitochondria/pathology , Mitochondria/ultrastructure , Hydrogen Peroxide/metabolism , Rats , Rats, Wistar , Endoplasmic Reticulum/drug effects , Endoplasmic Reticulum/pathology , Endoplasmic Reticulum/ultrastructureABSTRACT
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.