Metabolism tributyltin

Other workers have also made tributyltin-113 labelled compounds for environmental and metabolic studies. For instance, Brown and coworkers37 prepared bis(tributyltin-l 13) oxide by first refluxing tin-113, which was produced by neutron irradiation of metallic tin, in a bromine-chloroform solution for four hours. The resulting tin-113 tetrabromide was subsequently converted into tributyltin-113 bromide by reaction with three equivalents of unlabelled tetrabutyltin for four hours at 220 °C. The bis(tributyltin-113) oxide was finally obtained by hydrolysing the tributyltin-113 bromide with a KOH-95% ethanol solution... 

Oberdorster, E., D. Rittschof, and G.A. LeBlanc. 1998. Alteration of [14C]-testosterone metabolism after chronic exposure of Daphnia magna to tributyltin. Arch. Environ. Contam. Toxicol. 34 21-25. 

Lee RF (1985) Metabolism of tributyltin oxide by crabs, oysters and fish. Mar Environ Res 17 145-148... 

TBTO undergoes a condensation reaction with cellulose to form a tributyltin alkoxide (57). This reaction with cellulose could prevent metabolism by inhibiting the extracellular enzymes of the wood-destroying fungi. However, such a reaction is unlikely to be initiated in situ because the alkoxide is highly susceptible to hydrolysis (58). 

Studies on tributyltin uptake and depuration from food or water by rats, crabs, oysters, and fish showed that in all species it was accumulated and metabolized, at least partly, within 48 h to dibutyltins, monobutyltins, and more polar metabolites however, oysters (Crassostrea virginica) metabolized... 

Effects of xenobiotics on reproduction have also been observed, which presumably could have been due either to the effects of activated metabolites, or to the induction/inhibition of enzymes involved in reproductive processes, e.g. the cytochromes P-450. In the dog-whelk, Nucellus lapillus, exposure to tributyltin results in the development of imposex (the growth of a penis and vas deferens in females) (Bryan et al. 1987), and the process is indicated to be initiated by concentrations of xenobiotics as low as 1 ng 1" (Gibbs et al. 1987). The latency of oviposition and the number of egg masses and eggs were affected in L. stagnalis exposed to 2,2 - or 4.4 -dihalogenated biphenyls, and metabolic activation of the xenobiotics was postulated as a cause (Wilbrink et al. 1987). 

Schuphan, L., Westphal, D., Haque, A. and Ebing, W., 1981. Biological and chemical behaviour of perhalogenmethylmercapto fungicides Metabolism and in-vitro reactions of dichlofluanid in comparison with captan. Am. Chem. Soc., Symposium Series, 158, 85-96. Schweinfurth, H. A. and Giinzel, P., 1987. The tributyltins Mammalian toxicity and risk evaluation for humans. Proc. Oceans, 87, 1421-37. Scott, C. R. and Wolf, P. A., 1962. Antibacterial activity of a series of quaternaries prepared from hexamethylenetetramine and halohydro-carbons. Appl Microbiol. 10, 211-16. 

Inhibition of macromolecrrlar synthesis and of the mitochondrial energy metabolism, reduction of DNA synthesis, and direct interaction with the cell membrane have aU been imphcated in the organotin-induced cytotoxicity. Interaction of the tributyltin compormds with the cell membrane was reported to cause the ion charmels to open. This is followed by an influx of extracelMar Ca ion giving an increased cytosohc calcium concentration. This extraceUrrlar calcium ion influx has been indicated in tributyltin-induced apotosis in mouse thymocytes. ... 

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