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Ethylcholine mustard aziridinium ion (AF64A), a neurotoxic choline analog, was evaluated for its interactions with the cholinergic system in mice. Parenterally administered AF64A was lethal (LD50 = 32.6 mumol/kg i.v.) and the lethality could be antagonized even at 8 LD50 doses by pretreatment with choline (714 mumol/kg i.p.) 2 min earlier. Mice that were(More)
The present study was undertaken to characterize [3H]ifenprodil binding in rat brain. [3H]Ifenprodil showed saturable, high-affinity binding at 4 degrees C. Specific binding, defined with 10 microM ifenprodil as a competitor, was inhibited biphasically by the s receptor ligands, GBR 12909, 1,3-di-o-tolylguanidine (DTG), and(More)
Compound AF64A, ethylcholine mustard aziridinium ion (0.4-8 nmol) was stereotaxically administered into rat dorsal hippocampus, and neurochemical changes were determined 5 days later. AF64A treatment, over an almost 10-fold dose range, resulted in a significant (up to 70%) decline in choline acetyltransferase activity. In the same tissue samples,(More)
A loss in the number of functional, sodium ion-dependent, high-affinity choline transport sites was observed in the cortex and hippocampus of mice given an intracerebroventricular injection of 65 nanomoles of AF64A (ethylcholine mustard aziridinium ion) 3 days earlier. Such an effect was not observed in the striatum. This effect of AF64A represents a(More)
The neuropharmacologic effects of ethylcholine aziridinium ion, AF64A, were studied in cats, using various physiological techniques, to ascertain its synaptic site of action and to determine whether it may act as a cholinergic specific neurotoxin in vivo. Nictitating membrane contractions elicited by preganglionic nerve stimulation (1-16 Hz) were diminished(More)
About 20 min prior to training in a shock-motivated 14-unit T-maze, young (3-4 months) and aged (24-25 months) male Fischer-344 rats were given s.c. injections of either saline or dizocilpine (MK-801, 0.02 or 0.04 mg/kg), a non-competitive antagonist of the N-methyl-D-aspartate (NMDA) receptor. The aged rats showed a dose-dependent impairment in maze(More)
Four classes of non-mammalian vertebrates were examined for the presence of both 'brain-specific' and 'peripheral-type' binding sites for benzodiazepines in the central nervous system. 'Brain-specific' binding sites for benzodiazepines were found in the central nervous systems of all non-mammalian vertebrates studied. However, in contrast to mammals, either(More)
1. The effect of various peptide antagonists on capsaicin-induced (250 micrograms per ear) ear inflammation has been examined. 2. Co-administration of the substance P (SP) antagonist [D-Pro2,D-Trp7,9]SP at 100 and 300 micrograms per ear with capsaicin markedly attenuated oedema, whereas a vasopressin antagonist was ineffective. 3. Using the same scheme, the(More)
Acidified extracts of rat antral stomach chromatographed on octadecylsilane cartridges contained material that inhibited the binding of [3H]Ro 5-4864 (4'-chlorodiazepam) and [3H]nitrenidipine to "peripheral-type" benzodiazepine receptors and dihydropyridine Ca2+-channel antagonist binding sites respectively. This material reduced the apparent affinities of(More)
'Peripheral' binding sites for benzodiazepines are under neural or homonal control in the pineal gland, olfactory bulb, and kidney. These observations prompted a search for an endogenous substance which could modulate these sites under physiological conditions. Acidified methanol extracts from several tissues (e.g. stomach, kidney, lung) were found to(More)