Interference of MI-D, a new mesoionic compound, on artificial and native membranes

• Published in: Cell biochemistry and function Vol. 20; no. 1; pp. 31 - 37
• Main Authors: Cadena, Silvia M.S.C., Carnieri, Eva G.S., Echevarria, Aurea, de Oliveira, Maria Benigna Martinelli
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01-03-2002
• Subjects: Animals; Cinnamates - pharmacology; Diphenylhexatriene - analogs & derivatives; Diphenylhexatriene - metabolism; Fluorescence Polarization; Intracellular Membranes - chemistry; Intracellular Membranes - drug effects; Intracellular Membranes - metabolism; Ionophores - antagonists & inhibitors; Kinetics; Male; Membrane Fluidity - drug effects; Membranes, Artificial; mesoionic compound; Mitochondria, Liver - drug effects; Mitochondria, Liver - metabolism; Nigericin - antagonists & inhibitors; Osmolar Concentration; osmotic and iso-osmotic swelling; Permeability - drug effects; Potassium - metabolism; Rats; Rats, Wistar; Thiadiazoles; Thiazoles - pharmacology; Uncoupling Agents - pharmacology; Valinomycin - antagonists & inhibitors
• ISSN: 0263-6484; 1099-0844
• DOI: 10.1002/cbf.932

MI‐D (4‐phenyl‐5‐(4‐nitrocinnamoyl)‐1,3,4‐thiadiazolium‐2‐phenylamine chloride), a new mesoionic compound, decreased the rate of swelling induced by valinomycin‐K+, as well as induced swelling in the presence of nigericin‐K+. Shrinkage was also affected, suggesting interference with the inner mitochondrial membrane, which would affect both fluidity and elasticity. Fluorescence polarization of DPH and DPH‐PA, probing the core and outer regions respectively, of the DMPC and native membranes, indicated that MI‐D shifts the midpoint of phase transition to higher values and orders of the fluid phase. These alterations in membrane fluidity are thus related to MI‐D effects on the energy‐linked functions of mitochondria. Copyright © 2001 John Wiley & Sons, Ltd.