Cypermethrin-induced plasma membrane perturbation on erythrocytes from rats: reduction of fluidity in the hydrophobic core and in glutathione peroxidase activity

• Published in: Toxicology (Amsterdam) 2002-06, Vol.175 (1), p.91-101
• Main Authors: Gabbianelli, Rosita, Falcioni, Giancarlo, Nasuti, Cinzia, Cantalamessa, Franco
• Format: Article
• Language: English
• Subjects: Animals; Antioxidant enzymes; Biological and medical sciences; Catalase - blood; Cell Membrane - drug effects; Cell Membrane - enzymology; Cell Membrane - physiology; Cypermethrin; Erythrocyte Membrane - drug effects; Erythrocyte Membrane - enzymology; Erythrocyte Membrane - physiology; Fluorescence Polarization; Glutathione Peroxidase - blood; Insecticides - toxicity; Lipid oxidation; Lipid Peroxides - biosynthesis; Male; Medical sciences; Membrane fluidity; Membrane Fluidity - drug effects; Membrane Proteins - metabolism; Methemoglobin - metabolism; Pesticides, fertilizers and other agrochemicals toxicology; Pyrethrins - toxicity; Rat erythrocytes; Rats; Rats, Wistar; Superoxide Dismutase - blood; Toxicology
• ISSN: 0300-483X; 1879-3185
• DOI: 10.1016/S0300-483X(02)00058-6

The effects of treatment with the synthetic insecticide cypermethrin on plasma membrane fluidity, lipid peroxidation and antioxidant status in rat erythrocytes were investigated. Rats were treated by gavage with a low dose (12.5 mg/kg body weight per day) of cypermethrin in corn oil for 60 days. DPH and TMA-DPH fluorescence anisotropy experiments show that cypermethrin treatment, compared with controls, induced a significant decrease in erythrocyte membrane fluidity measured by DPH, while no changes were observed using TMA-DPH. Cypermethrin treatment also induced a significant increase in the lipid peroxidation, measured by the formation of conjugated dienes. The increased oxidative stress resulted in a significant decrease in the acitivity of glutathione peroxidase. The results are discussed in terms of preferential localization of cypermethrin in the hydrophobic core of the membrane, where it increases lipid packing and consequently decreases membrane fluidity.