Participation of Drosophila melanogaster alcohol dehydrogenase (ADH) in the detoxification of 1-pentene-3-ol and 1-pentene-3-one

Abstract

The participation of the ADH enzymes in the detoxification by D. melanogaster of 1-pentene-3-ol (also called pentenol) and its oxidized product, 1-pentene-3-one (usually known as ethyl-vinyl-ketone or pentenone) have been studied using the LR lines. For this purpose flies of Adhs Adhs (SS) and AdhF AdhF (FF) genotypes were independently pretreated with a 2 per cent isopropanol (2-propanol) solution and the survivors exposed to water, to a 00075 per cent pentenol solution or to a 0•00375 per cent pentenone solution. After one day in these solutions, the ability to tolerate both compounds was checked and the ADH activity of the surviving flies was measured and compared with those of control flies not pretreated with isopropanol. Additionally, the effects of pentenone on ADH enzymes have been studied by comparing them with those of acetone.Our results show that, in contrast to acetone, pentenone neither reduced significantly the ADH activity in vivo nor altered the normal proportion of ADH isozymes of either SS or FF flies. Our findings also demonstrate that the isopropanol pretreatment implied a considerable decrease in sensitivity not only to pentenol (60 and 91 per cent for SS and FF flies, respectively) but also to pentenone (72 and 80 per cent for SS and FF flies, respectively). After isopropanol pretreatment, FF flies continued exhibiting higher ADH activities than SS ones. However, FF pretreated flies displayed higher tolerance to pentenol and a similar tolerance to pentenone than SS animals.Our results suggest that pentenol (unsaturated secondary alcohol) and isopropanol (saturated secondary alcohol) may be detoxified by slightly different processes (both ADH-activity-dependent), and that pentenone could not be accumulated in the fly but transformed into another compound(s) by means of some ADH-independent mechanism(s).

Characterization of a Hemoglobin Adduct from Ethyl Vinyl Ketone Detected in Human Blood Samples

“…One possibility is the formation from linolenic acid, which has been suggested as a source of EVK in certain foods . Another example is the formation of EVK as a metabolite from 1-penten-3-ol, which has been shown for Drosophila melanogaster . This compound is also used as a flavouring and fragrance additive and found naturally in banana, orange juice, raspberry, and other commonly consumed food products .…”

Effect of acetone feeding on alcohol dehydrogenase activity in the olive fruit fly, Bactrocera oleae

“…They have also confirmed that ADH function is impaired by acetone in vivo as well, as shown by insensitivity to pentenol treatment in those flies with low levels of ADH activity. Pentenol (1-pentene-3-ol) is a secondary unsaturated alcohol and was chosen for study because Sofer and Hatkoff (1972) suggested that, in vivo, ADH oxidizes it into a lethal ketone, ethyl vinyl ketone (pentenone), which is a compound two or three times more toxic than the former (Garrido et al, 1988). This procedure preferentially kills flies with high levels of ADH activity, because pentenone does not appear to be metobolized by Drosophila and its accumulation is highly toxic to flies.…”