Thermoregulatory responses to environmental toxicants: The interaction of thermal stress and toxicant exposure
- US Army Research Institute of Environmental Medicine, Thermal and Mountain Medicine Division, Kansas Street, Building 42, Natick, Massachusetts 00760-5007 (United States), E-mail: lisa.r.leon@us.army.mil
Thermal stress can have a profound impact on the physiological responses that are elicited following environmental toxicant exposure. The efficacy by which toxicants enter the body is directly influenced by thermoregulatory effector responses that are evoked in response to high ambient temperatures. In mammals, the thermoregulatory response to heat stress consists of an increase in skin blood flow and moistening of the skin surface to dissipate core heat to the environment. These physiological responses may exacerbate chemical toxicity due to increased permeability of the skin, which facilitates the cutaneous absorption of many environmental toxicants. The core temperature responses that are elicited in response to high ambient temperatures, toxicant exposure or both can also have a profound impact on the ability of an organism to survive the insult. In small rodents, the thermoregulatory response to thermal stress and many environmental toxicants (such as organophosphate compounds) is often biphasic in nature, consisting initially of a regulated reduction in core temperature (i.e., hypothermia) followed by fever. Hypothermia is an important thermoregulatory survival strategy that is used by small rodents to diminish the effect of severe environmental insults on tissue homeostasis. The protective effect of hypothermia is realized by its effects on chemical toxicity as molecular and cellular processes, such as lipid peroxidation and the formation of reactive oxygen species, are minimized at reduced core temperatures. The beneficial effects of fever are unknown under these conditions. Perspective is provided on the applicability of data obtained in rodent models to the human condition.
- OSTI ID:
- 21180480
- Journal Information:
- Toxicology and Applied Pharmacology, Vol. 233, Issue 1; Conference: 2007 TRAC: 2007 toxicology and risk assessment conference: Emerging issues and challenges in risk assessment, West Chester, OH (United States), 23-26 Apr 2007; Other Information: DOI: 10.1016/j.taap.2008.01.012; PII: S0041-008X(08)00028-8; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0041-008X
- Country of Publication:
- United States
- Language:
- English
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