کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2571750 1128649 2007 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Lysophosphatidylcholine hydrolases of human erythrocytes, lymphocytes, and brain: Sensitive targets of conserved specificity for organophosphorus delayed neurotoxicants
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست بهداشت، سم شناسی و جهش زایی
پیش نمایش صفحه اول مقاله
Lysophosphatidylcholine hydrolases of human erythrocytes, lymphocytes, and brain: Sensitive targets of conserved specificity for organophosphorus delayed neurotoxicants
چکیده انگلیسی

Brain neuropathy target esterase (NTE), associated with organophosphorus (OP)-induced delayed neuropathy, has the same OP inhibitor sensitivity and specificity profiles assayed in the classical way (paraoxon-resistant, mipafox-sensitive hydrolysis of phenyl valerate) or with lysophosphatidylcholine (LysoPC) as the substrate. Extending our earlier observation with mice, we now examine human erythrocyte, lymphocyte, and brain LysoPC hydrolases as possible sensitive targets for OP delayed neurotoxicants and insecticides. Inhibitor profiling of human erythrocytes and lymphocytes gave the surprising result of essentially the same pattern as with brain. Human erythrocyte LysoPC hydrolases are highly sensitive to OP delayed neurotoxicants, with in vitro IC50 values of 0.13–85 nM for longer alkyl analogs, and poorly sensitive to the current OP insecticides. In agricultural workers, erythrocyte LysoPC hydrolyzing activities are similar for newborn children and their mothers and do not vary with paraoxonase status but have high intersample variation that limits their use as a biomarker. Mouse erythrocyte LysoPC hydrolase activity is also of low sensitivity in vitro and in vivo to the OP insecticides whereas the delayed neurotoxicant ethyl n-octylphosphonyl fluoride inhibits activity in vivo at 1–3 mg/kg. Overall, inhibition of blood LysoPC hydrolases is as good as inhibition of brain NTE as a predictor of OP inducers of delayed neuropathy. NTE and lysophospholipases (LysoPLAs) both hydrolyze LysoPC, yet they are in distinct enzyme families with no sequence homology and very different catalytic sites. The relative contributions of NTE and LysoPLAs to LysoPC hydrolysis and clearance from erythrocytes, lymphocytes, and brain remain to be defined.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Toxicology and Applied Pharmacology - Volume 224, Issue 1, 1 October 2007, Pages 98–104
نویسندگان
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