Revival: Biological Effects of Low Level Exposures to Chemical and Radiation (1992)

BIPHASIC DOSE-RESPONSE RELATIONSHIPS 65

Figure 4.1. Structures of chlordecone, mirex, photomirex, and phenobarbital.

Chlordecone amplifies the toxicity of several halomethanes closely related

to CCI4. Mirex and photomirex, despite being close structural analogues of

chlordecone, essentially do not possess this propensity. Phenobarbital, a

commonly employed drug in interaction studies at high doses, does

increase liver injury of CCI4, but this enhanced liver injury is inconsequential

to animal survival and health, since the animals are able to recover from

potentiated liver injury.

Table 4.2. Amplification of Lethal Effects of Halomethanes by Dietary Exposure of

Mice to Subtoxic Contaminants

Dietary

Pretreatment Halomethane

48-hr LD50

(mL/kg)

Increase

in Toxicity

(-fold)

Male mice

Control CHCI 3 0.067 —

Chlordecone (10 ppm) CHCI 3 0.16a 4.2

Mirex (10 ppm) CHCI 3 0.70 no change

Phenobarbital (225 ppm) CHCI 3 0.70 no change

Source: Adapted from Mehendale.16
Significantly different at P < 0.05.