ISSN:
0739-4462
Keywords:
avermectin
;
formamidine
;
ion-channel blocker
;
neurotoxicant
;
pesticide
;
pyrethroid
;
sodium gradient
;
Chemistry
;
Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Cultured central neurons from the American cockroach, Periplaneta americana, have been used to investigate the uptake of [3H]serotonin. The neurones accumulate [3H]serotonin from the extracellular medium by both a high-and a low-affinity system. The activity of the high-affinity mechanism is decreased by low temperature and metabolic poisons, and is dependent on sodium and chloride ions. Both depolarising levels of external potassium ions and veratridine decrease the high-affinity uptake system, suggesting it is influenced by the transmembrane potential. The pyrethroid insecticides, deltamethrin and permethrin, enhance the inhibitory effect of veratridine. Pyrethroid enhancement is completely blocked by tetrodotoxin, and neither pyrethroid affects the uptake system in the absence of veratridine. Avermectin B1A is a powerful inhibitor of the high-affinity uptake system, and its effect is blocked by picrotoxin. High-affinity uptake of [3H]serotonin is inhibited by imipramine and amitriptyline; desipramine has no significant effect on this uptake. The activity of the high-affinity system is also reduced by 8-hydroxy-dipropylaminotetralin, α-methyl-serotonin, and 1-(3-chlorophenyl)piperazine. Dopamine, noradrenaline, octopamine, and the formamidine insecticides, chlordimeform and demethylchlordimerform, are moderate inhibitors of the high-affinity uptake system. The formamidine effect is not blocked by tetrodotoxin or picrotoxin.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/arch.940120405
