Urinary 2,5-hexanedione increases with potentiation of neurotoxicity in chronic coexposure to n -hexane and methyl ethyl ketone

Abstract

The present study showed that urinary concentrations of 2,5-hexanedione increased with potentiation of n-hexane neurotoxicity. Urinary 2,5-hexanedione concentration does not necessarily reflect the exposure concentration of n-hexane in coexposure to n-hexane along with MEK or other solvents, but it may be useful as a marker in the assessment of neurotoxicity in coexposure to n-hexane and other solvents.

Possible metabolic interaction between hexane and other solvents co-exposed at sub-occupational exposure limit levels

“…A number of studies have been conducted since the late 1970s on the possible eects of co-exposed solvents on the metabolism of HEX (Altenkirch et al 1978, 1982a, b, Takeuchi et al 1981, Iwata et al 1984, Abou-Donia et al 1985, Ladefoged and Perbellini 1986, Shibata et al 1990a, b, Nylen and Hagman 1994, Nylen 1996, Ichihara et al 1998). The animals exposed were in most cases rats, and the solvents tested for combined eects included TOL, xylenes (XYL) and MEK.…”

“…Co-exposure to MEK was generally accompanied by an increase in PNS toxicity (Altenkirch et al 1978, 1982b, Iwata et al 1984, Shibata et al 1990a, b, Ichihara et al 1998. Interestingly, the MEKinduced increase in PNS toxicity was coupled with reduction in free-HD in serum (Iwata et al 1984) or total-HD in urine (Shibata et al 1990b) when duration of co-exposure was short (e.g., 8 weeks), but with an increase in total-HD in urine after prolonged exposure (Ichihara et al 1998).…”

“…Accordingly, attention has been placed on possible modi®cation of the toxicokinetics and even the toxicodynamics of HEX, owing to the combined exposure of HEX with other solvents (Altenkirch et al 1978, 1982a, b, Veulemans et al 1982, 1993, Iwata et al 1984, Abou-Donia et al 1985, Shibata et al 1990a, b, Nylen and Hagman 1994, Nylen 1996, Cardona et al 1996, van Engelen et al 1997, Ichihara et al 1998. The studies were, however, conducted mostly under rather extensive exposure conditions, and it was especially so in cases of animal experiment studies.…”

Changes in n -hexane toxicokinetics in short-term single exposure due to co-exposure to methyl ethyl ketone in volunteers

“…Vertical lines indicate ± one standard deviation on the first day of co-exposure to n-hexane and MEK but increased in chronic exposure, in parallel with potentiation of neurotoxicity [7]. The authors consider that MEK might inhibit n-hexane metabolism in short-term exposure, but induce oxidation enzymes in long-term exposure and facilitate n-hexane metabolism at high concentration.…”

Binding of Some Environmental Pollutants to Corn Protein Zein Studied by High-Performance Liquid Chromatography

“…The majority of organic solvents are volatile or semi-volatile and more or less soluble in water, therefore, they can equally occur in the atmosphere, 1 water, 2 sediment 3 and soil. 4 Furthermore, organic solvents such as alkanes, 5 benzene, 6 and alcohols 7 may represent serious health risk factors. The toxic effects of organic solvents are not entirely understood at the level of molecular biology.…”