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. 2013 Sep 30;8(9):e76011.
doi: 10.1371/journal.pone.0076011. eCollection 2013.

Correlation between levels of 2, 5-hexanedione and pyrrole adducts in tissues of rats exposure to n-hexane for 5-days

Hongyin Yin  1 , Ying Guo, Tao Zeng, Xiulan Zhao, Keqin Xie
Affiliations

Correlation between levels of 2, 5-hexanedione and pyrrole adducts in tissues of rats exposure to n-hexane for 5-days

Hongyin Yin et al. PLoS One. .

Abstract

Background: The formation of pyrrole adducts might be responsible for peripheral nerve injury caused by n-hexane. The internal dose of pyrrole adducts would supply more information for the neurotoxicity of n-hexane. The current study was designed to investigate the tissue distributions of 2, 5-hexanedione (2,5-HD) and pyrrole adducts in rats exposed to n-hexane, and analyze the correlation between pyrrole adducts and 2,5-HD in tissues.

Methods: Male Wistar rats were given daily dose of 500,1000, 2000, 4000 mg/kg bw n-hexane by gavage for 5 days. The rats were sacrificed 24 hours after the last administration. The levels of 2, 5-hexanedione and pyrrole adducts in tissues were measured by gas chromatography and Ehrlich's reagent, respectively. The correlations between 2, 5-hexanedione and pyrrole adducts were analyzed by linear regression.

Results: Dose-dependent effects were observed between the dosage of n-hexane and 2, 5-hexanedione, and pyrrole adducts in tissues. The highest level of 2, 5-hexanedione was found in urine and the lowest in sciatic nerve, while the highest level of pyrrole adducts was seen in liver and the lowest in serum. There were significant correlations among the free 2, 5-hexanedione, total 2, 5-hexanedione and pyrrole adducts within the same tissues. Pyrrole adducts in serum showed the most significant correlation with free 2, 5-hexanedione or pyrrole adducts in tissues.

Conclusion: The findings suggested that pyrrole adducts in serum might be a better indicator for the internal dose of free 2, 5-hexanedione and pyrrole adducts in tissues.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Tissue distributions of free 2,5-HD, total 2,5-HD and pyrrole adducts at 24 hours after the last administration of rats which were given daily dose of 500, 1000, 2000 or 4000 mg/kg n-hexane for 5 days (n=8).
Free 2, 5-HD and total 2, 5-HD were not detected in tissues of control group rats, the detection limit was 1.0 nmol/ml or nmol/g. Pyrrole adducts in serum and urine were 1.23 ± 0.26, 0.83 ± 0.13 nmol/ml, respectively. Pyrrole adducts were not detected in kidney, liver, spinal cord, brain, sciatic nerve, the detection limit was 0.20 nmol/g.
Figure 2
Figure 2. Dose-dependent effects between dosage of n-hexane and levels of free 2, 5-HD, total 2, 5-HD and pyrrole adducts in tissues (n=8).
Figure 3
Figure 3. Percentage of free 2,5-HD to total 2,5-HD in different tissues of rats (n=8).
Figure 4
Figure 4. Correlations between free and total 2,5-HD in different tissues (n=8).
Figure 5
Figure 5. Conversion ratio of free 2,5-HD to pyrrole adducts in different tissues.
Figure 6
Figure 6. Correlations between free 2, 5-HD and pyrrole adducts in different tissues of rats (n=8).
Figure 7
Figure 7. Corrections between free 2, 5-HD in urine, 2, 5-HD in serum, pyrrole adducts in urine, pyrrole adducts in seru m and free 2, 5-HD, pyrrole adducts in kidney, liver, brain, spinal cord and sciatic nerve (n=8).
See this image and copyright information in PMC

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