Relationship between toxicokinetics of carbaryl and effect on acetylcholinesterase activity in Pomacea patula snail.
The 96-h LC(50) value of carbaryl was 14.6 microg/mL for the snail Pomacea patula. Organisms were exposed for 72 h to a low sublethal concentration (0.1 of LC(50)) using a semistatic contamination system; bioconcentration and elimination experiments were performed evaluating simultaneously acetylcholinesterase (ACHase) activity. The inhibition of the digestive gland ACHase reached 76% when the carbaryl concentration in tissue was 3.2 microg/g. The increased enzyme inhibition was observed concomitantly with the bioconcentration of carbaryl until 7 h. ACHase inhibition was linearly dependent on the uptake and bioconcentration of carbaryl (r(2)=0.87). The transfer of snails to carbaryl-free water after 72 h of exposure was followed by rapid monophasic elimination with a half-life of 1.0 h. However, ACHase activity levels never returned to control values. These results revealed that the bioconcentration might play a critical role in contributing to the toxicity of carbaryl.
Mora
B R
BR
Universidad Autónoma Metropolitana-Iztapalapa, México, D.F., Mexico. ltabche@vmredipn.ipn.mx
Martínez-Tabche
L
L
Sánchez-Hidalgo
E
E
Hernández
G C
GC
Ruiz
M C
MC
Murrieta
F F
FF
D000818:Animals; D012721:Carbaryl / Q000493:pharmacokinetics / Q000633:toxicity*; D002800:Cholinesterase Inhibitors / Q000633:toxicity*; D007306:Insecticides / Q000633:toxicity*; D012908:Snails
D002800:Cholinesterase Inhibitors; D007306:Insecticides; D012721:Carbaryl