Spectrophotometric determination of pyrrole-like substances in urine of rat and man: an assay for the evaluation of 2,5-hexanedione formed from n-hexane.
Male Wistar rats exposed to atmospheric n-hexane excreted in their urine substances which gave rise to absorption spectra like those of pyrroles after the reaction with Ehrlich's reagent. A simple spectrophotometric assay was developed to determine these "pyrrole-like substances" in urine. Their excretion kinetics were evaluated by exposing rats for 8 h to atmospheric n-hexane concentrations between 50 and 3000 ppm. The dose-response curve revealed saturation kinetics according to Michaelis-Menten, Vmax being 1.12 [delta E526.ml urine/8 h n-hexane exposure] and "Km", the atmospheric n-hexane concentration at Vmax/2, being 250 ppm. The excretion of pyrrole-like substances closely correlated with that of 2,5-hexanedione measured by Fedtke and Bolt (1987). Pyrrole-like substances were also found in the urine of a male volunteer. When exposing the person for 3 h to atmospheric n-hexane at a concentration of 146 ppm (equivalent to 55 ppm/8 h) the excreted amount was twice the background value. Due to the sensitivity of this assay it is possible to determine pyrrole-like substances in urine according to the present German MAK or US TLV conditions for n-hexane (50 ppm/8 h).
Kessler
W
W
Gesellschaft für Strahlen- und Umweltforschung, Institut für Toxikologie, Neuherberg, Federal Republic of Germany.
Heilmaier
H
H
Kreuzer
P
P
Shen
J H
JH
Filser
M
M
Filser
J G
JG
D000818:Animals; D006586:Hexanes / Q000378:metabolism*; D006588:Hexanones / Q000378:metabolism*; D006801:Humans; D007659:Ketones / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D011758:Pyrroles / Q000652:urine*; D051381:Rats; D011919:Rats, Inbred Strains; D012680:Sensitivity and Specificity; D013053:Spectrophotometry
D006586:Hexanes; D006588:Hexanones; D007659:Ketones; D011758:Pyrroles; C026385:n-hexane; C011269:2,5-hexanedione