Unity and diversity of responses to xenobiotics in organisms.
A conceptual treatment of the mechanisms involved in the process of toxicosis by diverse agents in different tissues indicate a likely unspecific, common, central process in addition to specific precipitating factors acting on a particular site in a cascade of events. Free radicals, membrane functions and calcium functions appear to be links in the common pathway. Such a central mechanism could be interrelated with immunological defenses as well as genotoxic changes at different sites, suggesting parallel or related evolution of these antistress mechanisms. Many radical scavengers, antioxidants, membrane stabilizers, nutritional supplements and calcium modulators have proved beneficial either in reducing toxic impact, delaying the development of lesions or even reversing the effects. Similarly, recent evidences show that some immunomodulators can act as antioxidants and antigenotoxicants. Thus, the status of body defenses which may vary from one individual to the other have a role in deciding the effects under the same quantified risks with varying relative responses. Whether modulation of physiological defenses against stress could help in developing prophylactic measures remains an open question.
Kakkar
P
P
Ecotoxicology Section, Industrial Toxicology Research Centre, Lucknow, India.
Jaffery
F N
FN
Viswanathan
P N
PN
D000818:Animals; D000917:Antibody Formation; D002118:Calcium / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D006801:Humans; D010084:Oxidation-Reduction; D015262:Xenobiotics / Q000633:toxicity*
D015262:Xenobiotics; D002118:Calcium