ROUTE-SPECIFIC CARDIORESPIRATORY AND NEUROMUSCULAR CHANGES FOLLOWING ORGANOPHOSPHOROUS POISONING IN RATS

Organophosphorous compounds cause a variety of physiological effects. The effect of various routes of administration of these compounds on t he pathophysiology is still an open question. The present study addres ses the effect of two organophosphorous compounds, namely diisopropyl fluorophosphate and methyl-isopropyl phosphonofluoridate, given by two different routes (i.v. and s.c.), on physiological parameters in anae sthetized and artificially ventilated rats. Both organophosphorous com pounds produced a dose-dependent rise in blood pressure, bradycardia a nd twitch potentiation after i.v. administration. These effects are me diated by muscarinic as well as alpha-adrenoreceptors and are not affe cted by adrenalectomy. However, after s.c. administration, both organo phosphorous compounds produced a dose-dependent transient hypotension and bradycardia, mediated by muscarinic receptors, without affecting o ther physiological parameters. The results indicate the route-specific effects of these compounds on the cholinergic-catecholaminergic inter actions in rats.