Effect of high linear energy transfer radiation on biological membranes

Abstract

Cellular membranes are vital elements, and their integrity is extremely essential for the viability of the cells. We studied the effects of high linear energy transfer (LET) radiation on the membranes. Rabbit erythrocytes (1 x 10(7) cells/ml) and microsomes (0.6 mg protein/ml) prepared from liver of rats were irradiated with 7Li ions of energy 6.42 MeV/u and 16O ions of energy 4.25 MeV/u having maximum LET values of 354 keV/microm and 1130 keV/microm, respectively. 7Li- and 16O-induced microsomal lipid peroxidation was found to increase with fluence. The 16O ions were more effective than 7Li ions, which could be due to the denser energy distribution in the track and the yield of free radicals. These findings suggested that the biological membranes could be peroxidized on exposure to high-LET radiation. Inhibition of the lipid peroxidation was observed in the presence of a membrane-active drug, chlorpromazine (CPZ), which could be due to scavenging of free radicals (mainly HO* and ROO*), electron donation, and hydrogen transfer reactions. The 7Li and 16O ions also induced hemolysis in erythrocytes. The extent of hemolysis was found to be a function of time and fluence, and showed a characteristic sigmoidal pattern. The 16O ions were more effective in the lower fluence range than 7Li ions. These results were compared with lipid peroxidation and hemolysis induced by gamma-radiation.

Effects of agmatine on chlorpromazine toxicity in the liver of Wistar rats: the possible role of oxidant/antioxidant imbalance

“…The results presented here indicate that acute CPZ administration leads to liver damage through processes involved in oxidative modification of lipids, which are strengthened by the negative correlation between the concentration of TBARS and O 2 •- production 48 h after CPZ administration. Previously, it was shown that CPZ inhibits microsomal NADPH-induced LPO [ 31 ], while other authors have shown that the LPO inhibition after CPZ administration is a result of removing free radicals (OH • i ROO • ) [ 8 ]. Combined treatment with CPZ+AGM failed to induce changes in TBARS concentration in comparison with the CPZ group, indicating that the protective effects of AGM are not due to the influence on lipid peroxides in liver tissue [ 11 ].…”

Radioprotective effect of sesamol on γ-radiation induced DNA damage, lipid peroxidation and antioxidants levels in cultured human lymphocytes

“…Therefore, it is necessary to assess the protective action of such commonly used phytochemicals and exploit their possible application in radiation therapy of cancer as an alternative source of non-toxic radioprotectors. Some reports are available regarding plant extracts and phytochemicals on radiation induced cellular damage in model as well as in animal systems (Choudhary et al, 1998;Shimoi et al, 1996;Goel et al, 2004) but the protective effects of plant extracts and phytochemicals on radiation induced DNA damage, lipid peroxidation and antioxidant status are not thoroughly investigated.…”

Heavy Ion Microbeam Irradiation Induces Ultrastructural Changes in Isolated Single Fibers of Skeletal Muscle

“…In vitro studies indicated that heavy ion beams induce dimerization/shortening of membrane lipid by oxidation and alter the membrane fluidity (Schön et al, 1994;Choudhary et al, 1998;Ziegler and Wessels, 1998).…”