Inhibition of Growth by Benzene Hexachloride Isomers and Protective Effect of Glucose as Measured by Cell Counting Technique.

The purpose of this study is to evaluate the effects of benzene hexachloride isomers on root growth and the antagonism of these effects by selected chemical compounds. Interest has developed in gamma benzene hexachloride because it is highly toxic to insects (40). Five isomers of benzene hexachloride have been isolated (19) and the structural properties of most of them are well understood (40). The gamma and delta isomers cause mitotic arrest at metaphase (8, 9, 13, 28, 30). The toxicity of the gamma isomer, known commercially as Lindane, has been studied extensively (8, 14, 18, 23, 28, 34, 38), but little work has been done on the delta isomer (8, 38). Benzene hexachlorides possess certain properties characteristic of typical narcotic compounds, two of which are the lack of polar groups in the molecule and the limited solubility in water. Owing to the lack of polar groups, it would be predicted that benzene hexachloride (BHC) molecules would accumulate preferentially in the lipid phase boundaries of the protoplast (2). Following such accumulation, changes in cell structure and organization may occur which greatly influence the direction and rate of chemical reactions (13, 33). One of the first reported antagonists of gamma benzene hexachloride was meso-inositol (9, 12, 22, 27). Earlier, this finding was of interest because of the supposed structural analogy between gamma benzene hexachloride and the biologically important inositols. It now appears, however, that the delta isomer, and not the gamma isomer, is isomorphous with mesoinositol (17). D'AMATO (12), on the other hand, reported a delaying action of meso-inositol on the C-mitotic and C-tumor action of gamma benzene hexachloride, which occurred at 15 to 190 C, but not at 26 to 270 C. D'Amato also observed a delaying action of sucrose and other sugars and ascribed these effects to a change in permeability to the BHC. Antagonisms of this type are suggestive of those observed against x-radiation by sodium cyanide (3), thiourea (31) and vitamin P (41). LEVAN and OSTERGREN (30) have discussed the mechanism of C-mitotic action at some length. These workers describe C-mitotic action as a narcosis of those factors which govern growth by cell division, and C-tumor action as a narcosis of those factors which govern growth by cell tension. C-tumor formation has a threshold separate from C-mitosis (37). Mc-