[ RadSafe ] Heavy Metal Hormesis

[Scott, Bobby]

Subject: Heavy Metal Hormesis

 

James Salsman (james at bovik.org) wrote: "Has anyone considered that these
"low level protective effects" might be stimulated by things other than
toxins and ionizing radiation?"

 

Our recent research has focused on low dose-radiation/chemical induced
protective biological effects.  We have published models (NEOTRANS2 and
more recently NEOTRANS3)that postulate the existence of a generalized,
low-dose-induced, protective apoptosis-mediated (PAM) process, which
when activated by radiation, chemicals, or other stressors selectively
removes cells that possess genomic instability (e.g. mutant cells,
precancerous cells) from the body. The PAM process is mediated via
reactive oxygen and nitrogen species and specific cytokines and provide
a mechanistic basis for the occurrence of hormetic-type, dose-response
relationships for stochastic effects such and mutations, neoplastic
transformation, and cancer.  Our website (http://www.radiation-scott.org
<http://www.radiation-scott.org/>  ) provides information on the earlier
NEOTRANS2 model and its refined current version (NEOTRANS3).  Also,
recent publications that relate to the indicated models follow below.

 

(1) Scott BR. A biological-based model that links genomic instability,
bystander effects, and adaptive response. Fundamental and Molecular
Mechanism of Mutagenesis.  Mutation Research 568:129-143, 2004.
[NEOTRANS3 model]

 

(2) Scott BR et al. Low dose-radiation and genotoxic chemical can
protect against stochastic biological effects.  Nonlinearity in Biology,
Toxicology, and Medicine 2:185-211, 2004. [NEOTRANS2 model]

 

(3) Scott BR. Low-dose radiation-induced protective process and
implications for risk assessment, cancer prevention, and cancer therapy.
Nonlinearity in Biology, Toxicology, and Medicine(in press).

 

Interestingly, the PAM process appears to not be induced by low doses of
high-LET alpha radiation by itself but may be induced by combined
low-dose-rate exposure to both gamma rays and alpha particles.  In this
case, gamma rays could protect from stochastic effects of alpha
radiation. This topic is covered in the above in-press paper.   If you
would like to receive via the mail a reprint of either or both of the
two already-published papers, then just send me an e-mail request that
includes your mailing address.

 

Those with interest in recent research findings related to hormetic-type
dose-response relationships my find the upcoming BELLE Conference of
interest. The website for the conference follows:
http://www.belleonline.com/preliminaryProgram.html 

 

Sincerely, Bobby R. Scott, Ph.D.