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THE EFFECTS OF NEOSTIGMINE UPON GANGLION RESPONSES AFTER ADMINISTRATION OF BLOCKING DRUGS
Author(s) -
FENNER PENELOPE A.,
HILTON J. G.
Publication year - 1963
Publication title -
british journal of pharmacology and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0366-0826
DOI - 10.1111/j.1476-5381.1963.tb01530.x
Subject(s) - neostigmine , blocking (statistics) , medicine , ganglion , ganglionic blocker , pharmacology , anesthesia , atropine , anatomy , hexamethonium , computer science , computer network
The effects of block of autonomic ganglia by chlorisondamine and by hexa‐methonium, the administration of neostigmine and of atropine upon blood pressure, nervous transmission through the superior cervical ganglion, stimulation of autonomic ganglia by dimethylphenylpiperazinium, and the carotid occlusion reflex, have been studied in the dog anaesthetized with sodium pentobarbitone. The results of these studies have shown: (1) A ganglion blocking agent blocks synaptic transmission in the superior cervical ganglion at the same time as it lowers blood pressure. Neostigmine administered after ganglion‐block raises the blood pressure without much change in the response to stimulation of the preganglionic cervical sympathetic nerve. (2) If the effects of preganglionic nerve stimulation are recorded as a contraction of the nictitating membrane, a ganglion‐blocking agent also abolishes this response at the same time as it blocks the reflex rise in blood pressure produced by occlusion of both common carotid arteries. Neostigmine administered under these conditions does not affect the responses of the nictitating membrane, but restores the carotid occlusion reflex. This restoration of reflex activity is sensitive to atropine, as is the blood pressure rise. (3) At the same time that neostigmine restores the carotid occlusion reflex, there is no restoration of sensitivity of autonomic ganglia to chemical stimulation by dimethylphenylpiperazinium. In these animals atropine not only blocked the restored carotid occlusion reflex, but produced a further inhibition of the pressor response to dimethylphenylpiperazinium. It is concluded that neostigmine may raise blood pressure by partially restoring autonomic ganglionic transmission, but that total ganglionic function is not restored.