We have simulated how the LTA4 and oxoETE dose response depends on the LOOH level and found that both were influenced significantly (Table 2).
As shown here, these motifs can produce ultrasensitive or non-monotonic dose-response depending on their biochemical parameters.
The likely increase in body temperature during the work shift could create a stress response that could move the radiation response (depending on the dose) either into or out of the dose window for protective effects.
Then, in the cancer-prone C57Bl/6 radiation sensitive Trp53+/- heterozygous mice developing lymphomas and osteosarcomas, Mitchel et al. demonstrated that the level of dose required to induce an adaptive response depends on the tumor type (Mitchel et al. 2003).
Rather than considering a chemical as having a single dose response curve for toxicity, chemicals appear to have different dose response curves depending on the life stage at which exposure occurs.
Bacterial pore-forming toxins have been studied in a number of systems including mammalian-cells, where toxin-receptor binding or damage to the membrane elicits a diverse array of responses depending on the toxin dose, cell type, and duration of exposure.
This biphasic dose response phenomenon has been known as hormesis, which are always characterized by J- or inverted U- shaped dose response curve, depending on the different endpoints measured (de la Rosa et al. 2004).
This dose response may depend on the characteristics of the population and/or on the presence of environmental factors, both of which influence results independently of intervention modalities.
As drug screen assays used for the dose response experiments depends on inhibition of cell proliferation, other biological functions such as apoptosis and DNA repair are likely to be involved in the efficacy of the drugs.
Since pharmacodynamic responses depend on dose, route of administration, and dosing regimen, it is apparent that additional experimental data would be needed to substantiate a statement regarding the 'greater' potency of NESP.
Effects observed in sensitive target tissues can also be caused by exposure-related changes in mechanisms governing normal negative feedback regulation of endocrine tissues and hormone secretion; such effects may also influence the dose-response relationship depending on exposure duration.
