Hexachlorocyclohexane pesticides reduce survival and alter plasma membrane structure of Chinese hamster V79 cells - Verma, S.P.; Rastogi, A.; Lin, P.-S. (Elsevier)
We studied the cytotoxic effects of α-, β-, γ-, and δ-hexachlorocyclohexanes (HCCH) on the survival of Chinese hamster V79 cells using clonogenic assays. Lethal dose yielding 50% cell survival (LD"5"0) suggests the following order of cytotoxicity: δ- + γ-HCCH (LD"5"0 4 μg/ ml) (1:1, ww, mixture) 〉 δ-HCCH (LD"5"0 6 μg/ml) 〉 γ-HCCH (LD"5"0 13 μg/ml) 〉; α-HCCH (LD"5"0 approx. 35 μg/ ml) β-HCCH. Structural changes in plasma membranes prepared from HCCH-treated V79 cells at dose yielding 10% cell survival (LD"1"0) were analyzed using Raman spectroscopy. Raman spectra of plasma membranes show bands at 2850, 2880-2890, and 2935 cm^-^1 in the C-H stretching region. The plot of the ratio (^I2880-2890/ ^I2850) vs temperature for control plasma membranes shows two transitions between -5 and 5 ^oC and between 12 and 20 ^oC. Plasma membranes prepared from γ- and δ-HCCH-treated Chinese hamster V79 cells show single transitions between -4 and 11 ^oC and between -2 and 11 ^oC, respectively. These changes in the thermal transition properties suggest that both γ- and δ-HCCH alter lipid and lipid-protein phases of the plasma membrane of V79 cells. Raman analysis of the amide I and amide III region spectra further suggest that δ-HCCH also alters the secondary structure and the environment of highly amidated segments of plasma membrane proteins. We suggest that the primary action of biologically active HCCH isomers is to disrupt the organization of the plasma membrane and that may affect cell viability.
http://dx.doi.org/10.1016/0003-9861(92)90453-4
Keywords: W; V; U