DISSECTION OF THE HORMETIC CURVE: ANALYSIS OF COMPONENTS AND MECHANISMS

The relationship between the dose of an effector and the biological response fre-quently is not described by a linear function and, moreover, in some cases the dose-response relationship may change from positive/adverse to adverse/positive with increas-ing dose. This complicated relationship is called “hormesis”. This paper provides a short analysis of the concept along with a description of used approaches to characterize hormetic relationships. The whole hormetic curve can be divided into three zones: I – a lag-zone where no changes are observed with increasing dose; II – a zone where benefi-cial/adverse effects are observed, and III – a zone where the effects are opposite to those seen in zone II. Some approaches are proposed to analyze the molecular components involved in the development of the hormetic character of dose-response relationships with the use of specific genetic lines or inhibitors of regulatory pathways. The discussion is then extended to suggest a new parameter (half-width of the hormetic curve at zone II) for quantitative characterization of the hormetic curve. The problems limiting progress in th