The use of carbamates, atropine, and 2-pyridine aldoxime methoiodide in the protection of Artemia salina against poisoning by carbophenothion.
The acute toxicity of carbophenothion to three age classes of Artemia salina was evaluated. An increase in toxicity of carbophenothion was found following longer development of A. salina. The effect of pretreatment with the nonselective muscarinic antagonist atropine, the two reversible acetylcholinesterase-inhibitors physostigmine and pyridostigmine, and the cholinesterase-reactivating oxime 2-pyridine aldoxime methochloride (2-PAM) on carbophenothion-induced lethality in 24-h-old A. salina was also investigated. The lethal action of carbophenothion was completely prevented by pretreatment of A. salina with 2-PAM. Atropine and pyridostigmine afforded a maximal protection of approximately 87% and 72%, respectively, compared to control values. In contrast, physostigmine was ineffective. The inhibitory effects of combinations of 10(-5) M atropine with physostigmine, pyridostigmine, or 2-PAM were greater than those elicited by either drug alone, with the maximum protection afforded being 92.58%, 100%, and 100%, respectively. In the presence of 10(-7) M atropine, neither pyridostigmine nor 2-PAM provided additional inhibition of the lethality compared to that with either drug alone, whereas the protection afforded by 10(-7) M atropine plus physostigmine increased as the concentration of carbamate increased (up to 10(-3) M). Pretreatment with pyridostigmine or physostigmine plus 2-PAM (10(-6) M) slightly enhanced the maximal inhibition of carbophenothion lethality compared to that with either drug alone. It is suggested that the most active combined pretreatment studied here was physostigmine plus atropine.
Sánchez-Fortún
S
S
Departamento de Toxicología y Farmacología, Facultad de Veterinaria, Universidad Complutense de Madrid, Spain. fortun@eucmax.sim.ucm.es
Barahona
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D000818:Animals; D001156:Artemia; D001285:Atropine / Q000494:pharmacology*; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D002801:Cholinesterase Reactivators / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D007306:Insecticides / Q000633:toxicity*; D007928:Lethal Dose 50; D018727:Muscarinic Antagonists / Q000494:pharmacology*; D009946:Organothiophosphorus Compounds / Q000633:toxicity*; D010830:Physostigmine / Q000494:pharmacology*; D011220:Pralidoxime Compounds / Q000494:pharmacology*; D011729:Pyridostigmine Bromide / Q000494:pharmacology*; D014874:Water Pollutants, Chemical / Q000633:toxicity
D002800:Cholinesterase Inhibitors; D002801:Cholinesterase Reactivators; D007306:Insecticides; D018727:Muscarinic Antagonists; D009946:Organothiophosphorus Compounds; D011220:Pralidoxime Compounds; D014874:Water Pollutants, Chemical; D001285:Atropine; C006901:carbophenothion; D010830:Physostigmine; D011729:Pyridostigmine Bromide; C028797:pralidoxime