A radical is any molecule that contains one or more unpaired electrons. Radicals are normally generated in many metabolic pathways. Some of these radicals can exist in a free form and subsequently interact with various tissue components resulting in dysfunction. The potential role of oxygen- and xenobiotic-derived free radical in the pathology of several human diseases has stimulated extensive research linking the toxicity of numerous xenobiotics and disease processes to a free radical mechanism.
Abstract: The effects of misonidazole (MISO) and two other nitroimidazoles (5‐NO 2 and 4, 5‐NO 2 ) on the bioelectric parameters of ion transport (potential difference and short circuit current) across frog skin as a membrane model, were studied in vitro . The nitroimidazoles investigated caused structure dependent effects on the sodium transport function of the membrane. MISO induced a biphasic action following administration on the external side of the membrane: after an initial enhancement, the potential difference and short circuit current signals both decreased. The other imidazole derivatives, 5‐NO 2 and 4, 5‐NO 2 , showed only one phase, whether administered on the external or internal membrane surface. All the nitroimidazoles investigated decreased sodium transport after internal or external surface administration. It was found that the 4, 5‐NO 2 imidazole derivative irreversibly decreased the bioelectric membrane parameters.
Protein kinase C comprises a family of at least 13 distinct serine/threonine kinase isoenzymes that have important actions in transmembrane signal transduction pathways and have been reported to regulate cell proliferation, differentiation, cell-to-cell interaction, cytoskeletal functions, gene transcription, apoptosis and drug resistance. The results of investigations show differential redistribution isoenzymes in each organ and their specific activity in determined diseases.
