| Literature DB >> 1057516 |
Abstract
Three components of the dose-response reaction, usually seen as three separate curves, are reviewed as a single continuum of the effect of the dose of any agent upon an organism. The usual considerations of any agent in toxicology are the harmful actions. The individual considerations of an essential nutrient or of a hormone usually suggests a positive action. The third component is the stimulatory action as understood in hormone research and as seen in many studies with minute doses of toxic materials. The coelescence of these concepts into one continuum gives a broad viewpoint which is helpful to understand the biologic implications of any toxic, nutritious or stimulating material under a variety of conditions. Such a view is useful in predicting results and in understanding the reaction of living organisms to their environments; when small amounts of a chemical are added to a biologic system, one parameter may be affected in one way and another parameter in the opposite manner. Consideration of the complete dose-response curve led to the concept of hormology, the sutdy of excitation. The thesis of hormology is that any harmful agent may be stimulatory for any parameter when it is administered in subharmful quantities to an organism existing in a suboptimum environment. Concepts fro hormology allow the suggestion that the zero equivalent point (zep) could be used to replace zero tolerance as a practical, legislative concept for dangerous chemicals in our environment. A reivew of three pharmacology texts revealed four types of dose-response curves. The alpha curve demonstrated a simple toxicity, the beta curve exhibited a single stimulation peak followed by a toxicity as more material was added; the gamma curve showed an initial harmful reaction followed by a stimulatory reaction which, in turn, was followed by a toxic reaction as the quantity of material administered was increased; and the delta curve was essentially a sign wave in which two peaks of stimulation were separated by a "harmful valley", then, as greater concentrations of material were administered, toxicity was noted. A brief review of agents which are stimulatory in minute doses showed that a considerable amount of work had been done with radiation and late work has established emf as a stimulatory vehicle. Little work is done with other physical agents. Organic chemical compounds are known to be stimulatory in small quantities; e.g. dietary antibiotics. The fact that antibiotics stimulate growth in germfree animals and the fact that nongermicides stimulate classic animals proves their direct effect on the animal tissues.Entities:
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Year: 1975 PMID: 1057516
Source DB: PubMed Journal: Environ Qual Saf Suppl ISSN: 0340-4714