The interaction of carbaryl with the metabolism of isolated hepatocytes: I. Effect on respiration and glycolysis.
The in vitro interaction of the insecticide 1-naphthyl-N-methylcarbamate (carbaryl) with respiration and the glycolytic pathway was studied in hepatocytes isolated according to a modified version of the method of Berry and Friend. The cells were subjected to concentrations of carbaryl at 0.01, 0.1 and 1.0 mM dissolved in 1% dimethylsulphoxide. The results show that dimethylsulphoxide induces a slight stimulation of the respiratory coefficients. Concentrations of carbaryl at 0.01 and 0.1 mM did not significantly modify oxygen consumption, but at 1.0 mM this was reduced by 40% in relation to the dimethylsulphoxide-treated group. On the other hand, the decrease in the metabolic production of CO2 is significant at even the lowest of the concentrations with resultant major changes in the respiratory quotient. The utilization of glucose is unchanged by treatment with carbaryl. The endogeneous production of lactic acid is unaffected by the presence of the exogenous agents studied. The net metabolic production of lactate was strongly inhibited by dimethylsulphoxide and further inhibited by increasing concentrations of carbaryl. 1 mM of carbaryl completely blocks the net glycolytic flux. The results indicate that carbaryl produces major changes at the glycolytic pathway of hepatic cells. But this result may be understood not as an effect due to carbaryl per se, but as the role of other factors such as dimethylsulphoxide or metabolites of nonenzymatic hydrolysis or carbaryl which also would be involved.
D000818:Animals; D012721:Carbaryl / Q000494:pharmacology*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis / Q000187:drug effects*; D066298:In Vitro Techniques; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains
D007773:Lactates; D019344:Lactic Acid; D005947:Glucose; D012721:Carbaryl; D004121:Dimethyl Sulfoxide