Hormesis is a biological imperative

[Muckerheide <muckerheide@attbi.com>]

Friends, FYI.

 

The following papers further indicate that "hormesis" is a biological

imperative.

 

Regards, Jim Muckerheide

Radiation, Science, and Health

==============================



> Toxicology 2002 Nov 15;180(2):139

> Metabolic modulation of carbon monoxide toxicity.

> 

> Omaye S.

> Department of Nutrition and Environmental Toxicology and Health Track,

> Environmental Sciences and Health Graduate Program, University of Nevada,

> 89557, Reno, NV, USA

> 

> Carbon monoxide (CO) gas is a product of the incomplete combustion of

> carbon-based fuels and substances. From a public health perspective, CO

> poisoning may be the cause of more than 50% of fatal poisonings in many

> industrial countries. The adverse effects of CO poisoning may be more

> widespread because of unreported situations and delayed neurologic effects,

> which may be linked to CO exposure. Chronic CO effects that are subtle, such

> as the adverse effects on vascular diseases, may increase the number of people

> at risk. The apparent role of CO as an important mediator of cell signaling is

> a paradox and may represent an example of hormesis, i.e. beneficial effects at

> low concentration but adverse effects at higher concentrations. Nevertheless,

> because CO can form ligands with iron (heme) and copper sites, the potential

> for metabolic intervention is likely. Furthermore, CO-induced oxidative stress

> opens the opportunity for modulating the adverse effects of CO with

> antioxidants (both water- and lipid-soluble compounds) and various factors

> involved with reducing oxidative stress. However, consideration must be given

> to the micro-environment in some situations that could potentially create more

> oxidation and subsequent metabolic damage if the combinations and

> concentrations of antioxidants are not correct, i.e. pro oxidant effects.

> Likewise, it is important that we take precautions in the development of

> antioxidant adjuvants to use with oxygen therapies in CO poisoning.

> 

> http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_u

> ids=12324190&dopt=Abstract

> 

> --------------------------------------------------------------

> 

> Ecotoxicol Environ Saf 2002 Jul;52(3):227

> Hormesis responses of free and immobilized light-emitting bacteria.

> 

> Christofi N, Hoffmann C, Tosh L.

> 

> Pollution Research Unit, School of Life Sciences, Napier University, 10

> Colinton Road, Edinburgh, EH10 5DT, Scotland, United Kingdom

> 

> The stimulatory effect of sublethal or low concentrations of toxic chemicals

> on organismal metabolism, referred to as hormesis, has been found to be common

> in the widely used Vibrio fischeri luminescence bioassay. In addition to the

> "normal" type alpha, we have demonstrated type beta and, possibly, type gamma,

> dose-response curves in free and immobilized V. fischeri bioassays developed.

> Understanding and utilizing data from hormesis responses are necessary in

> determining the toxicity of chemicals, singly or in complex mixtures, to

> natural biota without imposing excessive penalties to dischargers. At the same

> time, care must be taken not to relax environmental standards. This can only

> arise by fully investigating and understanding the role of hormesis in

> toxicity data used for risk assessment.

> 

> http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_u

> ids=12297084&dopt=Abstract



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