Open AccessInhibition of Rat Platelet 5‐Hydroxytryptamine Uptake by Chlorpyrifos and Carbaryl
Author(s) -
Sachana Magda,
Flaskos John,
Nikolaidis Efstathios,
Hargreaves Alan,
AlexakiTzivanidou Eleni
Publication year - 2001
Publication title -
pharmacology & toxicology
Language(s) - English
Resource type - Journals
eISSN - 1600-0773
pISSN - 0901-9928
DOI - 10.1111/j.0901-9928.2001.890409.x
Subject(s) - carbaryl , chlorpyrifos , pharmacology , platelet , toxicology , chemistry , pesticide , biology , medicine , ecology
The organophosphate insecticide chlorpyrifos and the carbamate insecticide carbaryl were investigated in adult male rats in terms of their effects on the activity of brain monoamine oxidase–A (MAO‐A) activity and on the platelet uptake of 5‐hydroxytryptamine (5‐HT). The activities of brain acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BuChE) were also determined. For each compound two different dosage regimens were employed. In the acute study, chlorpyrifos or carbaryl was administered at a single intraperitoneal dose of 100 mg/kg or 50 mg/kg, respectively. In the subacute study, chlorpyrifos was injected at a daily dose of 20 mg/kg for 7 days, while carbaryl was given at a daily dose of 10 mg/kg for 14 days. Acute chlorpyrifos administration produced a 85.01% inhibition of AChE and a 43.4% inhibition of BuChE but had no effect on MAO‐A activity and 5‐HT uptake. In contrast, subacute chlorpyrifos exposure caused a 94.96% inhibition of AChE and a 85.8% inhibition of BuChE and, also, elicited a significant (35.02%) reduction in the platelet uptake of 5‐HT. MAO‐A activity was not affected. Acute carbaryl administration produced a 56.38% AChE inhibition and a 55.95% BuChE inhibition and also caused a significant (26.36%) decrease in 5‐HT uptake but no change in MAO‐A. Subacute carbaryl exposure failed to affect significantly any of the biochemical parameters determined. Interference with the 5‐HT system by chlorpyrifos and carbaryl could contribute to the toxicity of these pesticides.