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At least 19 recordsLinked to original sources
PubMed1971

Specificity of some ganglion stimulants.

1. The specificity of several ganglion stimulants has been tested on the isolated guinea-pig ileum by measuring the dose ratios produced by concentrations of hexamethonium.2. Most ganglion stimulants are also active at postganglionic receptors, some as blocking agents (for example, lobeline and dimethylphenylpiperazinium), others as agonists (for example, o-aminophenethyltrimethylammonium and, to a lesser extent, nicotine). The most specific ganglion stimulant, with the least activity at postganglionic receptors, was p-aminophenethyltrimethylammonium.3. The affinity constants of lobeline and dimethylphenylpiperazinium for the muscarine sensitive receptors in the guinea-pig ileum are 1.05 x 10(6) and 3.71 x 10(4), respectively.4. The antagonism of p-aminophenethyltrimethylammonium by hexamethonium gave results consistent with competition up to dose ratios of about 20. Such results could also be obtained if the antagonism were non-competitive, however, provided large responses could be obtained with less than about 5% of the receptors in the ganglia activated. The affinity constant of hexamethonium is about 2.6 x 10(5).5. It is suggested that the affinity of hexamethonium can largely be ascribed to hydrophobic bonding.

Animals↗
PubMed1979

Changes of ventricular monophasic action potential duration by stellate ganglion stimulation in dogs.

Left or right stellate ganglion stimulation resulted in changes of ST segments and T waves of electrocardiogram. The present experiments were performed in an attempt to elucidate alpha-and beta-adrenergic actions, and calcium action on the monophasic action potential duration (APD), that is, the repolarizing phase of myocardium. During experiments in open-chest dogs, right ventricular pacing was performed for avoiding the acceleration of heart rate by stellate ganglion stimulation. Administration of phentolamine, propranolol or D600 prolonged APD, while hydrazine shortened it. However, stellate ganglion stimulation caused a prolongation of APD after infusion of propranolol or hydrazine, and a shortening of APD after infusion of phentolamine, D600 or hydrazine. These results indicate that alpha-and beta-adrenergic actions as well as calcium ions can be related to APD in the ventricular myocardium of dogs; apparently, alpha-adrenergic action prolongs APD and beta-adrenergic action shortens it.

Action Potentials↗
PubMedDate not supplied

Antagonism by propranolol of the ganglion stimulant action of 5-hydroxytryptamine.

The effects of racemic propranolol and its constituent isomers were studied on ganglionic stimulation produced in situ by close arterial injection of 5-HT and DMPP to the superior cervical ganglion. Ganglion stimulation was recorded in terms of the resultant contraction of the nictitating membrane. d,l-Propranolol caused a biphasic antagonism of the ganglion stimulant effect of 5-HT. At low doses, 0.5-10 mug, the antagonism was surmountable by increasing the amount of 5-HT. The l-isomer (0.2-4 mug) but not d-propranolol also caused antagonism. At higher doses, 0.1-5 mg, both d,l- and d-propranolol caused a second type of blockade of 5-HT which was not surmountable and resembled that seen with procaine. The ganglion stimulant effects of DMPP and acetylcholine were only antagonised by the higher doses of d- and d,l-propranolol. d,l-Propranolol did not reduce the direct stimulation by 5-HT on the muscle of the nictitating membrane.

Acetylcholine↗
PubMed1978

Uropharmacology: VII. Ganglionic stimulating and blocking agents.

A classification of the various ganglionic stimulants and blockers is presented, and their pharmacologic effects on the urinary bladder and urethra are discussed. Ganglionic stimulating drugs are of considerable interest in investigational work but are not presently used therapeutically. Ganglionic blockers include hexamethonium, tetraethylammonium, mecamylamine emepronium, pentolinium, chlorisondamine, and pemipidine. Of the numerous ganglionic blocking drugs that have appeared on the therapeutic scene, only mecamylamine, pentolinium, and trimethaphan are currently official.

Animals↗
PubMed1975

Non-uniform myocardial blood flow caused by stellate ganglion stimulation.

The blood flow through the anterior wall of the left ventricle has been studied during electrical stimulation of the left stellate ganglion of anesthetized dogs. The flow was continuously monitored by heated cross-thermocuple. Ganglion stimulation caused a significant increase in the flow through the outer half while producing relative ischemia of the inner half of the wall. Pretreatment with propranolol reduced regional difference of flow changes. Significantly augmented non-uniform flow changes, however, were produced by ganglion stimulation during hypertension caused by aortic constriction or by methoxamine. The results indicate non-uniform blood flow distribution which can be produced by sympathetic nerve excitation.

Animals↗
PubMed1998

A fluorescence-based method for assessing dural protein extravasation induced by trigeminal ganglion stimulation.

Neurogenic dural inflammation has been proposed as a source of pain during migraine. Unilateral electrical stimulation of the trigeminal ganglion causes the ipsilateral release of inflammatory neuropeptides and subsequent dural plasma protein extravasation, a component of neurogenic inflammation. We measured the amount of protein leaking into the dural tissue of guinea pigs following trigeminal ganglion stimulation by exploiting the complexation reaction of endogenous proteins with the fluorescent dye Evans Blue, instead of utilizing exogenous radiolabeled albumin as commonly done in the literature. The amount of Evans Blue trapped in dural tissue following electrical stimulation of the trigeminal ganglion was measured using a fluorescence microscope equipped with a spectrophotometer. This method utilized multiple measurements on each dura sample which resulted in very precise values using a small number of animals per point (n = 3). Sumatriptan and CP-122,288 were found to dose-dependently prevent neurogenic dural extravasation. The potencies of CP-122,288 and sumatriptan were found to be similar to those reported in the literature when similar experimental protocols were used.

Animals↗
PubMed2005

Reversal of cerebral vasospasm by sphenopalatine ganglion stimulation in a dog model of subarachnoid hemorrhage.

BACKGROUND: Sphenopalatine ganglion stimulation dilates the ipsilateral arteries of the normal dog anterior circle of Willis. This experiment tested whether similar stimulation would reverse cerebral vasospasm. METHODS: Six dogs underwent baseline angiography followed by creation of subarachnoid hemorrhage (SAH) by injection of autologous blood into the cisterna magna. Two days later, subarachnoid blood injection was repeated. Seven days later, angiography was repeated and the left sphenopalatine ganglion was exposed microsurgically. Angiography was repeated 15 minutes after exposure of the ganglion. The ganglion was then stimulated electrically 3 times and angiography repeated during, and 15 and 30 minutes after stimulation. The protocol was repeated again. Adequacy of stimulation was confirmed by the presence of immediate ipsilateral nasal mucus production. RESULTS: Subarachnoid hemorrhage was associated with significant vasospasm of both middle cerebral arteries (11% +/- 4% and 18% +/- 7%, P < .05, paired t tests). Exposure of the ganglion and sham stimulation produced no substantial changes in arterial diameters compared with the diameter before stimulation and after ganglion exposure (n = 2-6 per measurement, paired t tests). Ganglion stimulation produced significant dilatation of the ipsilateral extracranial and intracranial internal carotid, middle cerebral, and anterior cerebral arteries compared with the contralateral arteries (13% +/- 6% to 32% +/- 14%, P < .05, paired t tests). CONCLUSIONS: The mild to moderate vasospasm that results from SAH in dogs was reversed by sphenopalatine ganglion stimulation. Since this method carries a potential for human application, additional studies are warranted to determine the effects on more severe vasospasm.

Animals↗
PubMed1995

Trigeminal ganglion stimulation increases facial skin blood flow in the rat: a major role for calcitonin gene-related peptide.

Activation of the trigeminovascular system leads to neurogenic inflammation within the dura mater and cerebral vasodilatation. These processes have been implicated in the pathogenesis of migraine headache. Neurogenic vasodilator responses to trigeminal ganglion stimulation were investigated in rat facial skin, an area innervated by the trigeminal nerve. Microvascular blood flow changes in the facial skin were measured in anaesthetised rats, using laser Doppler flowmetry. Electrical stimulation of the trigeminal ganglion caused an ipsilateral increase in facial skin blood flow which was found to be frequency dependent (0.5-10 Hz). The role of several neuropeptides in these blood flow responses was studied using selective receptor antagonists. The calcitonin gene-related peptide antagonist, CGRP8-37 (400 nmol.kg-1, i.v.) had no effect on resting levels of facial skin blood flow, but markedly inhibited responses induced by trigeminal ganglion stimulation (5 Hz, 10 V, 1 ms for 30 s). However, neither the neurokinin-1 (NK1) receptor antagonist, RP67580 (0.23 or 2.3 mumol.kg-1, i.v.) nor the vasoactive intestinal peptide (VIP) antagonist, [p-Cl-D-Phe6,Leu17]-VIP (15 or 30 nmol.kg-1, i.v.) had any effect on these responses. These results suggest that CGRP is the major neuropeptide involved in the vasodilator response to trigeminal ganglion stimulation in rat facial skin. Clarification of the mechanisms involved in this neurogenic vasodilator response may aid the development of drugs that target the trigeminovascular system during migraine headache.

Animals↗
PubMed1988

The effect of sustained stellate ganglion stimulation on left ventricular contractility in the dog.

Although a progressive reduction in left ventricular contractility during sustained left stellate ganglion stimulation has been well documented, there have been no reports on the contractile state after nerve stimulation. Left ventricular contractility after cessation of 60 min of electrical (10 V. 10 Hz. 1 msec) left stellate ganglion stimulation has been assessed in open chest dogs. Before and 15 min after stimulation, left ventricular contractility was evaluated by the end-systolic pressure-segment length relationship using ultrasonic crystals during a stepwise aortic constriction to increase left ventricular afterload. Restimulation of the left stellate ganglion was also performed 15 min after cessation of the first stimulation. After sustained left stellate ganglion stimulation, the end-systolic points shifted to the right from the control and the slope of multiple pressure-segment length coordinates significantly decreased (102.5 +/- 16.1 to 76.5 +/- 10.2 mmHg/mm, mean +/- S.E., p less than 0.05, n = 5), indicating a depression of left ventricular contractility. Increased left ventricular dP/dt max and norepinephrine level in the coronary sinus gradually returned to near base line during 60 min of stimulation. These reduced responses lasted for at least 15 min after cessation of stimulation. The myocardial norepinephrine content was reduced to 0.59 +/- 0.08 (mean +/- S.E.) ng/mg wet tissue from 0.90 +/- 0.15 of the control level (p less than 0.05). These data suggested that left ventricular contractility decreased after sustained cardiac sympathetic nerve stimulation, probably due to norepinephrine reduction in the myocardium.

Animals↗
PubMed2005

Multisensory integration in the dorsal cochlear nucleus: unit responses to acoustic and trigeminal ganglion stimulation.

A necessary requirement for multisensory integration is the convergence of pathways from different senses. The dorsal cochlear nucleus (DCN) receives auditory input directly via the VIIIth nerve and somatosensory input indirectly from the Vth nerve via granule cells. Multisensory integration may occur in DCN cells that receive both trigeminal and auditory nerve input, such as the fusiform cell. We investigated trigeminal system influences on guinea pig DCN cells by stimulating the trigeminal ganglion while recording spontaneous and sound-driven activity from DCN neurons. A bipolar stimulating electrode was placed into the trigeminal ganglion of anesthetized guinea pigs using stereotaxic co-ordinates. Electrical stimuli were applied as bipolar pulses (100 micros per phase) with amplitudes ranging from 10 to 100 microA. Responses from DCN units were obtained using a 16-channel, four-shank electrode. Current pulses were presented alone or preceding 100- or 200-ms broadband noise (BBN) bursts. Thirty percent of DCN units showed either excitatory, inhibitory or excitatory-inhibitory responses to trigeminal ganglion stimulation. When paired with BBN stimulation, trigeminal stimulation suppressed or facilitated the firing rate in response to BBN in 78% of units, reflecting multisensory integration. Pulses preceding the acoustic stimuli by as much as 95 ms were able to alter responses to BBN. Bimodal suppression may play a role in attenuating body-generated sounds, such as vocalization or respiration, whereas bimodal enhancement may serve to direct attention in low signal-to-noise environments.

Acoustic Stimulation↗
PubMed1975

Ciliary ganglion stimulation. I. Effects on aqueous humor inflow and outflow.

Stimulation of the ciliary ganglion in an enucleated, arterially perfused cat eye preparation produced a sustained increase in aqueous humor formation and an increase in the rate of aqueous humor outflow. The increased aqueous humor formation induced by ciliary ganglion stimulation has been found to be pressure-dependent and therefore suggests that ultrafiltration may be the underlying mechanism of action. No change in capillary permeability of the ciliary body could be demonstrated.

Acetylcholine↗
PubMed1986

Muscarinic ganglionic stimulants: conformationally restrained analogues related to [4-[[N-(3-chlorophenyl)carbamoyl]oxy]-2-butynyl]trimethylammonium chloride.

The synthesis of a series of tertiary and quaternary cyclic analogues (isoarecolinol, dihydroisoarecolinol, arecolinol, and 3-pyrroline-3-carbinol derivatives) of [4-[[N-(3-chlorophenyl)carbamoyl]oxy]-2-butynyl]trimethylammonium chloride (McN-A-343) (1), a selective stimulant of muscarinic receptors in sympathetic ganglia (so-called M1 receptors), is reported. The compounds 3-10 were tested for muscarinic ganglion-stimulating activity by recording blood pressure responses in pithed rats. All tertiary compounds tested had no ganglion-stimulating activity. Among the series of quaternary derivatives, only the isoarecolinol analogues 4a and 4b showed considerable ganglion-stimulating effects, whereas the dihydroisoarecolinol (8), the arecolinol (6a, 6b), and the 3-pyrroline-3-carbinol derivatives (10) were much less potent. Our experiments therefore demonstrate that in this series a quaternary nitrogen atom, unsaturation at C2 of the ammonium side chain, and a certain spatial arrangement of the ammonium and the phenylcarbamate groups are essential for potent M1-receptor stimulating activity.

Animals↗
PubMed1976

Stereochemical analogs of a muscarinic, ganglionic stimulant. 2. Cis and trans olefinic, epoxide, and cyclopropane analogs related to 4-[N-(3-chlorophenyl)carbamoyloxy]-2-butynyltrimethylammonium chloride (McN-A-343).

Preparation of analogs of 4-[N-(3-chlorophenyl) carbamoyloxy]-2-butynyltrimethylammonium chloride [1 (McN-A-343)], cis- and trans-4-[N-(4-chlorophenyl)carbamoyloxy]-2-butenyltrimethylammonium iodides (5 and 6), and the corresponding epoxides and cyclopropanes is reported. Pharmacological testing for ganglion-stimulating activity demonstrated that the trans olefin 6 and trans epoxide 8 have properties similar to 1, while the trans cyclopropane analog 10 was inactive. All cis compounds were inactive. The muscarinic ganglion-stimulating properties of the active compounds are interpreted in terms of similar fit at the receptor level by the alkyltrimethylammonium ion and the ether oxygen 5.7 A distant, as well as an electron-rich center midway between groups in the form of a double bond or unshared electron pairs. Comparison of smooth muscle and ganglion-stimulating properties of the compounds showed that trans epoxide 8 was the most selective for muscarinic ganglionic sites.

(4-(m-Chlorophenylcarbamoyloxy)-2-butynyl)trimethy↗