Metal toxicity in two rodent species and redox potential: Evaluation of quantitative structure—activity relationships

Abstract

A quantitative structure-activity relationship study of acute toxicity in the mouse and rat is described for the soluble salts of a relatively large number of metals (between 25 and 30 in total). Electrode potential is the major determinant of acute metal toxicity (R = 0.85 and 0.86) for an intraperitoneal dose in the mouse, whereas the addition of ionic radius and polarizability enables the inclusion of notable outliers in the original expression, such as beryllium and barium, thus giving a good correlation (R = 0.87) with toxicity for 27 metal compounds. These findings are rationalized on the basis of relative ease of ionization, electron affinity, and transport factors of the metals and their ions, thus being consistent with the hard and soft acids and bases properties of metals and their biological reactivities.

Advances in Quantitative Ion Character‐Activity Relationships (QICARs): Using Metal‐Ligand Binding Characteristics to Predict Metal Toxicity

“…These data sets reported effects of seven or more metals to a variety of organisms and endpoints including enzyme inactivation, cultured cell viability, germination inhibition of fungi, bioaccumulation in a marine diatom, inhibition of bacterial bioluminescence (Microtox ), acute toxicity to soil nematodes and an array of aquatic invertebrates, and chronic effects on lethal or sublethal endpoints. Recent work by other groups has used this approach with additional ion qualities and plant [9] or mammalian species [10].…”

Carcinogenesis and Chemotherapy Viewed from the Perspective of Stoichiometric Network Analysis (SNA): What Can the Biological System of the Elements Contribute to an Understanding of Tumour Induction by Elemental Chemical Noxae (e.g., Ni2+, Cd2+) and to an Understanding of Chemotherapy?

“…Basic Types of (Auto)catalytic Cyclic Processes a) Autocatalytic process order > exit order b) Autocatalytic process order = exit order c) Autocatalytic process order < exit order d) No autocatalysis, but heterocatalysis (applies to numerous geochemical background processes, e.g., [23] 30 , and e) Cross catalysis, including symbioses a) corresponds to a strong (current) cycle, b) to a critical cycle, and c) to a weak cycle; d) is also a weak cycle, but it cannot be dominated biologically since reproduction no longer plays any substantial role in a reproduction order of O ak ≈ 0; e) is a critical cycle by definition because of mutual dependence -and has unstable long-term kinetics 31 . The nature of the cycle may change through cross-connection of reaction loops among themselves, the addition of highly reactive antagonists, the polymerization of the autocatalyst and the like, but always in the direction of weaker autocatalysis [15].…”

“…In this case heterocatalysis takes place instead of (biotic or inorganic) autocatalysis. 31 Similarly, symbiotic systems such as lichens are particularly suitable for identifying interference such as the influence of environmental noxae [21].…”

“…Empirically, there is also a relationship between the oxidizing effect (redox potential) of (various) metal ions and their acute toxicity [31].…”

The dubious origin of beryllium toxicity

“…This has leaded some authors [11] to use in their papers the word beryllium for both species, a source of confusion. Studies on the toxicity of beryllium and on chronic beryllium disease, CBD, are very numerous and extend over 60 years [1,5,8,[12][13][14][15][16][17]. For many authors, beryllium is the most toxic non-radioactive element in the periodic table [18,19], but Buchner does not agree having stated that "the acute toxicity of beryllium ions does not exceed that of other toxic cations like Cd 2+ , Ba 2+ , Hg 2+ or As 3+ " [20,21].…”