Significant Reductive Transformation of 6:2 Chlorinated Polyfluorooctane Ether Sulfonate to Form Hydrogen-Substituted Polyfluorooctane Ether Sulfonate and Their Toxicokinetics in Male Sprague-Dawley Rats.
Environ Sci Technol
; 56(10): 6123-6132, 2022 05 17.
Article
in En
| MEDLINE
| ID: mdl-33947185
ABSTRACT
62 chlorinated polyfluorooctane ether sulfonate (62 Cl-PFESA) was previously shown to undergo limited dechlorination in rainbow trout to yield 62 hydrogen-substituted polyfluorooctane ether sulfonate (62 H-PFESA) as the sole metabolite. However, the biotransformation susceptibility of 62 Cl-PFESA has not been investigated in mammals and the biological behavior of 62 H-PFESA has not been defined in any species. We investigated the respective transformation products of 62 Cl-PFESA and 62 H-PFESA and their toxicokinetic properties in male Sprague-Dawley rats as a mammalian model. 62 H-PFESA was the sole detectable metabolite of 62 Cl-PFESA, with a transformation percentage of 13.6% in rat liver, but it resisted further degradation. 62 Cl-PFESA also transformed to 62 H-PFESA in reductive rat liver S9 incubations but remained stable under oxidative conditions, suggesting a reductive enzyme-dependent transformation pathway. 62 Cl-PFESA was more enriched in lipid-rich tissues, while 62 H-PFESA was more prone to cumulative urinary excretion. From this perspective, it may suggest a detoxification mechanism for organisms to form the less hydrophobic 62 H-PFESA to alleviate total burdens. To date, 62 Cl-PFESA was the second perfluoroalkyl acid reported to undergo biotransformation in mammals. The toxicokinetic properties determined for 62 Cl-PFESA and 62 H-PFESA in blood and urine were found to be structure and dose dependent.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Alkanesulfonic Acids
/
Fluorocarbons
Limits:
Animals
Language:
En
Journal:
Environ Sci Technol
Year:
2022
Document type:
Article
Affiliation country:
China