Therapeutic Effects Of Neuronal Nicotinic Receptor Antagonism Against The Cholinesterase Inhibitor Poisoning

In the cholinesterase inhibitor poisoning, the symptoms of the muscarinism and nicotinism are both serious and typical. But in the treatment of the poisioning, more attention was put on the muscarinic receptor antagonism, and the nicotinic receptor antagonism was neglected. Recent years, It was found that neuronal nicotinic receptor has some effect on the reaction of the cholinesterase inhibitor poisoning. In our research, we study the effect of nicotinic receptor antagonism on muscarinic receptor antagonist in the treatment of the circulation failure and respiratory failure induced by the cholinesterase inhibitor.1 We investigate the changes of hemodynamic parameters and plasma vascular active substances before and after treatment with neuronal nicotinic receptor antagonist mecamylamine or muscarinic receptor antagonist atropine against the circulation failures induced by the cholinesterase inhibitor DDV in dogs. The results indicate that in anesthetized dogs intoxicated with cholinesterase inhibitor DDV, the circulation failure was characterized by the significant decreases in hemodynamic parameters MAP, +dp/dtmax,Vpm and-dp/dtmax. The plasma vascular active substances NO,ET and 6 -Keto - PGF1. were increased significantly. After treated with mecamylamine and atropine 15 min, all the hemodynamic parameters were increased markedly and all the three vascular active substances were decreased significantly. After treated 60min, all the parameters were almost resumed to the normal level. The therapeutic effects of combination of mecamylamine and atropine were much better than those ofmecamylamine or atropine used separately. Then,we can conclude that the therapeutic effects of mecamylamine, an antagonist of nicotinic receptors, against circulation failures induced by cholinesterase inhibitor DDV were observed in this experiment, and the levels of vascular active substances NO,ET and 6 - Keto - PGF1. in plasma could reflect the severity of circulation failure,and the synergism between mecamylamine and atropine against DDV were determinded.2 On the respiratory failure caused by omethoate in rats, through investigating the artery blood gas, the symptoms and survival times of the rats, we study the therapeutic effect of mecamylamine, a nicotinic acceptor antagonist. The results indicate that, omethoate can cause severe respiratory failure of the rats, to which mecamylamine has no effect as a cure medicine when applied solely, but combined with atropine and PAM, it can significantly reduce the symptom and prolong the living time of the rats treated.3.On the omethoate poisoning model of the mice, we research the effects of different compatibilities between mecamylamine and atropine on the death rates of the animals. The results show that, the anti-poison effect of the combination of mecamylamine and atropine is obviously superior to that of atropine used solely, and the best molarity proportions of compatibilities between them are that of 4:1~10:1.