The influence of carbaryl on the uptake of (3H)-noradrenaline (3H)-NA by rat hypothalamic slices.
The uptake of (3H)-NA by rat hypothalamic slices was investigated following carbaryl poisoning. The insecticide was administered to rats orally in a single dose of 50% LD50 and of 20% LD50, and in repeated dosing for 14 days (5% LD50 daily). The kinetics of (3H)-NA uptake was defined by the modified Lineweaver-Burk plots (Rmax was used instead of Vmax and Km was replaced with t05 max). The results indicated that in all the experiments carbaryl elevated the (3H)-NA uptake by hypothalamic slices in a dosage dependent fashion (insignificantly at the 20% LD50 dose level, p greater than 0.05) as evidenced by the increased Rmax values. However, carbaryl simultaneously decreased the kinetics of the process in the hypothalamus since t0.5max values were enhanced (insignificantly at the 5% LD50 dose level, p greater than 0.05). Carbaryl produced a dose-dependent increase of t0.5max values. The changes in the (3H)-NA uptake may be related to the increase of NA level in the hypothalamus following exposure to carbaryl observed by other authors.
Jablońska
J
J
Department of Toxicology, Medical Academy Warsaw, Poland.
Brzeziński
J
J
D000818:Animals; D012721:Carbaryl / Q000633:toxicity*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D007928:Lethal Dose 50; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D012721:Carbaryl; D009638:Norepinephrine