title: [Algebraic definition of toxicologic constants characteristic of lethality].
abstract: The Hill equation, mi = Mmax/(1 + [Ti/t]ni), describes the mortality (mi) versus time (t) of a normal or an intoxicated organism. Parameters Ti and ni are, in turn, functions of doses (di) of toxin, according to the same equation. Doses dT50 and dN50 eliciting a half-maximum variation of parameters Ti and ni are both fundamental toxicological constants. The tangents (delta i) to the curve of mortality vs time also obey the same type of equation and allow an additional family of constants, d delta 50, to be derived. In contrast, LD50 varies between zero and infinite. The model can be readily generalized to the opposite phenomena involving a stimulation of the life span of organisms.
authors.affiliation: Laboratoire de Biochimie, I.N.R.A., Montfavet.
authors.forename: M
authors.initials: M
authors.lastname: Bounias
mesh_terms: D007928:Lethal Dose 50; D008433:Mathematics; D008722:Methods; D009026:Mortality
vernacular_title: Définition algébrique de constantes toxicologiques caractéristiques de la létalité.