title: Cholinesterase and paraoxonase (PON1) enzyme activities in Mexican-American mothers and children from an agricultural community.
abstract: Exposure to organophosphate and carbamate pesticides can lead to neurotoxic effects through inhibition of cholinesterase enzymes. The paraoxonase (PON1) enzyme can detoxify oxon derivatives of some organophosphates. Lower PON1, acetylcholinesterase, and butyrylcholinesterase activities have been reported in newborns relative to adults, suggesting increased susceptibility to organophosphate exposure in young children. We determined PON1, acetylcholinesterase, and butyrylcholinesterase activities in Mexican-American mothers and their 9-year-old children (n=202 pairs) living in an agricultural community. We used Wilcoxon signed-rank tests to compare enzymatic activities among mothers and their children, and analysis of variance to identify factors associated with enzyme activities. Substrate-specific PON1 activities were slightly lower in children than their mothers; however, these differences were only statistically significant for the paraoxon substrate. We observed significantly lower acetylcholinesterase but higher butyrylcholinesterase levels in children compared with their mothers. Mean butyrylcholinesterase levels were strongly associated with child obesity status (body mass index Z scores >95%). We observed highly significant correlations among mother-child pairs for each of the enzymatic activities analyzed; however, PON1 activities did not correlate with acetylcholinesterase or butyrylcholinesterase activities. Our findings suggest that by age 9 years, PON1 activities approach adult levels, and host factors including sex and obesity may affect key enzymes involved in pesticide metabolism.
authors: Center for Environmental Research and Children's Health, 50 University Hall, School of Public Health, University of California, Berkeley, California 94720-7360, USA.
authors: Veronica
authors: V
authors: Gonzalez
authors: Karen
authors: K
authors: Huen
authors: Subha
authors: S
authors: Venkat
authors: Kelly
authors: K
authors: Pratt
authors: Pin
authors: P
authors: Xiang
authors: Kim G
authors: KG
authors: Harley
authors: Katherine
authors: K
authors: Kogut
authors: Celina M
authors: CM
authors: Trujillo
authors: Asa
authors: A
authors: Bradman
authors: Brenda
authors: B
authors: Eskenazi
authors: Nina T
authors: NT
authors: Holland
mesh_terms: D000383:Agriculture; D043303:Aryldialkylphosphatase / Q000378:metabolism*; D002648:Child; D002802:Cholinesterases / Q000378:metabolism*; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D017058:Mexican Americans; D010575:Pesticides / Q000633:toxicity; D011247:Pregnancy
chemical_list: D010575:Pesticides; D002802:Cholinesterases; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human