Quinoline

Biotransformation and kinetics

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 for cross-reference:

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

Test material information

Constituent 1

Reference substance name:

Quinoline

EC Number:

202-051-6

EC Name:

Quinoline

Cas Number:

91-22-5

Molecular formula:

C9H7N

IUPAC Name:

quinoline

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.