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Ecotoxicological information

Biotransformation and kinetics

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Administrative data

Endpoint:
biotransformation and kinetics
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
no data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: No guideline available for this kind of study however, the study is well described and is scientifically valid.
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
publication
Title:
UPTAKE AND BIOTRANSFORMATION OF QUINOLINE BY RAINBOW TROUT
Author:
Bean RG, Dauble DD, Thomas BL, Hanf RW, Chess EK
Year:
1985
Bibliographic source:
Aquatic toxicology 7: 221-239

Materials and methods

Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
The experiments were designed to determine the distribution and fate of quinoline within freshwater fish. Of further interest was to investigate biotransformation pathways through characterization of metabolites accumulated in various tissues. Rainbow trout were exposed to subacute levels of quinoline in defined water systems, and tissue concentrations were analyzed by capillary gas chromatography using a nitrogen/phosphorous detector or by gas chromatography/mass spectrometry.
GLP compliance:
not specified
Type of medium:
aquatic

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
[14C]Quinoline, uniformly labeled in the benzo ring, was synthesized and was purified (> 99%) by liquid chromatography. Specific activity was 7.6 µCi/µM. Quinoline standard (>99%) was obtained from Aldrich.

Results and discussion

Transformation products:
yes

Any other information on results incl. tables

Table 1 : Estimates of the uptake and elimination rate constants and bioconcentration factors of quinoline plus metabolites (total radioactivity) and parent compound alone. Determinations based on whole body extracts of juvenile rainbow trout, mean weight. All values mean ± standard error

Compound

Uptake rate constant (K1)

Elimination rate constant (K2)

Bioconcentration factor

Based on uptake

Based on elimination

Based on uptake

Based on elimination

Quinoline metabolites

0.58 ± 0.13 h-1

0.073 ± 0.022 h-1

0.074 ± 0.024 h-1

7.89 ± 0.82

7.78 ± 1.77

Quinoline

1.02 ± 0.54 h-1

0.27 ± 0.16 h-1

-a

3.73 ± 0.43

-a

aElimination rate constant for quinoline was not calculated. All fish collected after 1 h in clean water contained less than detectable levels of quinoline.

Table 2 : Mean and range concentrations of parent compound and primary metabolites in selected tissues of juvenile rainbow trout. The 24-h and 48-h sample periods represent duration of exposure to 1.0 ± 0.1 mg/L quinoline in water and the 72-h sample period is after 24-h depuration. Concentrations are given as µg/g tissue.

Sample size (n) ranged from 3 to 6 for each time period.

Tissue

24h

48 h

72 h

 

1

2

3

4

1

2

3

4

1

2

3

4

Gallbladder and bile

54 (7-66)

70 (41-94)

280 (130-480)

23 (0-69)

70 (22-140)

140 (5-290)

360 (130-730)

110 (0-340)

17 (1-44)

100 (40-180)

220 (92-340)

230 (9-880)

Liver

1.4 (1.0-2.0)

0.7 (0-1.3)

1.6 (0.4-2.7)

13 (8-23)

1.4 (0.6-2.4)

0.1 (0-0.3)

0.3 (0-0.3)

23 (6-47)

ND

0.9 (0.3-1.5)

0.8 (0-1.4)

1.9 (1.3-3.5)

Kidney

3.4 (2.0-4.4)

0.1

ND

4.7 (2.8-7.1)

0.9 (0.1-2.0)

ND

ND

3.6 (2.6-4.6)

0.3 (0-0.4)

0.1

ND

1.1 (0.2-2.6)

Muscle

0.6 (0.3-1.7)

ND

ND

0.5 (0-1.9)

0.7 (0.2-1.8)

<0.1

<0.1

0.2 (0.0-0.8)

<0.1

<0.1

<0.1

0.3 (0.1-0.9)

Gut

4.4 (1.0-7.8)

0.4 (0.2-0.7)

0.8 (0.3-1.8)

3.7 (0-11)

3.2 (0.5-8.0)

0.3 (0-0.9)

0.5 (0-1.7)

4.3 (2.0-7.3)

0.1 (0-0.2)

0.3 (0.1-0.7)

0.2 (0-0.3)

1.2 (0.5-2.9)

Gill

1.0 (0.2-2.2)

<0.1

<0.1

1.4 (0.9-2.2)

0.9 (0.8-1.0)

<0.1

ND

1.0 (0.7-1.6)

<0.1

<0.1

<0.1

0.4 (0.2-0.8)

Eye

6.3 (3.9-9.5)

<0.1

ND

2.8 (1.5-5.4)

4.5 (0.6-9.6)

ND

ND

0.9 (0-2.8)

0.6 (0.2-1.6)

ND

ND

0.4 (0-0.9)

1 = quinoline

2 = hydroxyquinoline

3 = quinolinethiol

4 = unidentified

ND = not detected

Applicant's summary and conclusion

Executive summary:

Rainbow trout readily absorb and metabolize [14C]quinoline when exposed to 1 mg/l concentration in water. Juvenile fish accumulated over 60% of the total radiolabel body burden in the gall bladder as quinoline metabolites after 48 h exposure followed by 24 h in clean water. Hydrolysis products of the metabolites, isolated by alkaline digestion and base-catalysed acetylation, were found to be hydroxyquinolines and quinolinethiols. There is evidence that the hydroxy form was present in the gallbladders as the glucuronide was obtained from thin layer chromatographic experiments, and by cleavage with beta-glucuronidase The thiol, identified by high and low resolution mass spectrometry, predominated over the hydroxy derivative in most tissues examined. Relative body burdens of quinoline plus metabolites alter 48 h were in the order gallbladder > muscle > gut > eyes > liver similar to gill similar to kidney.