| 释义 |
hormesis, n. Biol.
Brit. |hɔːˈmiːsɪs|, U.S. |hɔrˈmisɪs|
[‹ Hellenistic Greek ὅρµησις rapid motion, eagerness (taken in the sense of ‘stimulation’) > comb. form) + -σις -sis suffix. Compare earlier hormetic adj.]
The phenomenon or condition of a substance or other agent having a beneficial physiological effect at low levels of exposure even though toxic or otherwise harmful at higher levels.
Used esp. with reference to a known toxin, or to ionizing radiation.
1943C. M. Southam & J. Ehrlich in Phytopathology 33 520 An increase in growth rate of many of the fungi in extreme dilutions of the extract is also evident... It is..likely that the phenomenon represents an initial response, followed by progressive desensitization to subinhibitory concentrations of a toxic constituent of the extract. The term hormesis (adj. hormetic) is proposed to designate such a stimulatory effect of subinhibitory concentrations of any toxic substance on any organism. 1963Lancet 16 Nov. 1041/2 On two occasions Ps. pyocyanea appeared more resistant to streptomycin and showed hormesis with tetracycline. 1972Science 29 Sept. 1154 Hormesis is a common and widespread phenomenon. Insecticides have been shown to stimulate growth of insects as well as plants, and fungicides can stimulate growth of fungi. 1996Los Angeles Times (Nexis) 20 May b4 Molecular geneticists have shown that ‘hormesis’, the low-level exposure of an organism to a stress agent that is harmful at higher levels, can actually extend life span in mice and fruit flies. |