[Toxicology of cupric sulfate in honeybees. I. New algebraic parameters of lethality as alternatives to the LD50].
A full kinetic study, over the whole life span of individuals, has been performed on the lethality of honeybees receiving by chronic administration: 0; 0.25; 0.5; 1; 2 g.l-1 of cupric sulfate in sucrose syrups. Three algebraic parameters, based on the Hill equation, allow a complete description of the curves: the time corresponding to the death of 50% of the individuals (LT50), the Hill coefficient (nt) and the slope of the tangent at the inflexion point (delta) corresponding to the maximum mortality rate. Studying the variations of the 3 parameters versus administered doses, leads to new relations allowing the calculation of the dose decreasing by half the 50% survival time of controls (dT50), and the doses increasing up to half the maximum, the value of nt(dnt50) and the value of delta (d delta 50). The experimental data gave: dT50 = 0.27 g.l-1; dnt50 = 0.51 g.l-1; d delta 50 = 0.93 g.l-1. These indexes, which represent new objective parameters for the characterization of lethality, should be substituted to the LD50 whose values vary between zero and infinite according to the time arbitrarily chosen for their calculation, and wear only a very restrictive significance.
Nectoux
M
M
Laboratoire de Biochimie, INRA-Avignon, Montfavet.
Bounias
M
M
D000206:Actuarial Analysis; D000818:Animals; D001516:Bees / Q000187:drug effects* / Q000378:metabolism; D003300:Copper / Q000494:pharmacology / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D007928:Lethal Dose 50; D009026:Mortality; D013997:Time Factors
D003300:Copper; C017846:cupric sulfide
Toxicologie du sulfate cuivrique chez l'Abeille. I. Nouveaux paramètres algébriques de létalité comme alternative à la DL50.