Physiological modes of action of toxic chemicals in the nematode Acrobeloides nanus
Alda Alvarez,O., Jager, T., Marco Redondo, E. and Kammenga, J. E. 2006.
Physiological modes of action of toxic chemicals in the nematode Acrobeloides nanus
Environmental Toxicology and Chemistry, 25: 3230 - 3237.
Abstract
To gain a better understanding of the mechanisms through which a
chemical exerts toxicity, a deeper insight is needed regarding the
physiological processes that take place during a toxic stress. This
issue can have important benefits for risk assessment, because it can
contribute to a better interpretation of toxicity data. Here, we study
the physiological mode of action of three different compounds
(cadmium, carbendazim, and pentachlorobenzene) with an experimental
data based approach using whole life-cycle toxicity data from the
nematode Acrobeloides nanus. We use a process-based model, based on
the dynamic energy budget theory, to study the fluxes of energy
related to physiological processes and their variation throughout the
life cycle. With this approach, we unravel the physiological modes of
action based on resource allocation, and we model the effects of the
different modes of action at the population level. The mode of action
of carbendazim was through a decrease in assimilation, with an
additional effect on the production of reactive oxygen species
(ROS). Cadmium increased the costs of growth, with an extra effect on
ROS production, and pentachlorobenzene decreased assimilation. We
compared the present results with those of previous studies using the
nematode Caenorhabditis elegans, and we found that the modes of action
for the three compounds differed from those found in A. nanus, showing
that the life-history characteristics of each organism have a clear
influence on the resulting modes of action. This highlights the
importance of the interactions between a chemical and the biological
characteristics of the organism in determination of the resulting
physiological modes of action.