Antispasmodic action of propinox on the isolated human gallbladder: possible mechanism of action.

Propinox is an antispasmodic drug frequently used in the treatment of disorders of the gastrointestinal tract, the uterus and the gallbladder, but little is known about its relaxing activity in gallbladder tissue. The main objective of this study was to determine the antispasmodic activity of propinox, compared to other antispasmodics, in the gallbladder and to assess its binding affinity to receptor sites which may be involved in its mechanism of action. Antispasmodic activity of propinox, (-) scopolamine-n-butyl bromide, atropine and verapamil was determined in human gallbladders to reduce the risk of interspecies variability. Inhibitory activities (ED50) of carbachol-induced contraction were: atropine 5.03 x 10(-8) M > propinox 1.25 x 10(-7) M > verapamil 6.63 x 10(-6) M > (-) scopolamine-n-butyl bromide 5.4 x 10(-5) M. pD'2 for propinox was 6.94, indicating non competitive inhibition of carbachol action. Radioligand binding studies were performed to determine if the antispasmodic action of the drug involved binding to muscarinic receptors or calciumantagonist sites. The inhibition constant (Ki) of propinox for muscarinic receptors of guinea pig ileum smooth muscle, which contains a mixed M2-M3 receptor population, was 1.6 x 10(-6) M. Ki for brain muscarinic receptors (M1) was 1.0 x 10(-4) M, for cardiac receptors (M2) 1.2 x 10(-6) M and from salivary gland receptors (M3) 1.5 x 10(-6) M. For binding to the dihidropiridine calcium antagonist binding sites, Ki were: 4.9 x 10(-5) M for propinox and 2.2 x 10(-7) M for verapamil. For the phenylalkylamine binding sites Ki were: 5.0 x 10(-6) M for propinox and 3.5 x 10(-8) M for verapamil. For the benzothiacepine binding sites, Ki for propinox was 5.2 x 10(-6) M. The following may be concluded: 1.--The antispasmodic activity of propinox in isolated human gallbladder was comparatively less potent than that of atropine and more potent than those of verapamil and (-) scopolamine-n-butyl bromide. 2.--Propinox showed binding to muscarinic and calcium receptors that can be related to its antispasmodic activity; suggesting that the drug is an antispasmodic with anticholinergic and musculotropic activity. 3.--The dual mechanism of action, anticholinergic and calcium-blocking, would induce synergism of pharmacodynamic effects and minimize adverse events of pure antimuscarinic drugs or calcium antagonists.

Antispasmodic action of propinox on the isolated human gallbladder: possible mechanism of action

Propinox is an antispasmodic drug frequently used in the treatment of disorders of the gastrointestinal tract, the uterus and the galbladder, but little is known about its relaxing activity in gallbladder tissue. The main objective of this study was to determine the antispasmodic activity of propinox, compared to other antispasmodics, in the gallblader and to assess its binding affinity to receptor sites which may be involved in its mechanism of action. Antispasmodic activity of propinox, (-) scopolamine-n-butyl bromide, atropine and verapamil was determined in human gallbladders to reduce the risk of interspecies variability. Inhibitory activities (ED50) of carbachol-induced contraction were: atropine 5.03x10(-8) M>propinox 1.25x10(-7) M> verapamil 6.63x10(-6)M> (-) scopolamine-n-butyl1 bromide 5.4x10(-5) M. pD'2 for propinox was 6.94, indicating non competitive inhibition of carbachol action. Radioligand binding studies were performed to determine if the antisplasmodic action of the drug involved binding to muscarinic receptors or calciumatagonist sites. The inhibition constant (Ki) of proponix for muscarinic receptors of guinea pig ileum smoth muscle, which contains a mixed M2-M3 receptor population, was 1.6x10(-6) M. Ki for brain muscarinic receptors (M1) was 1.0x10(-4) M, for cardiac receptors (M1) was 1.0x10(-4)M, for receptors (M2) 1.2x10(-6)M and from salivary gland receptors (M3) 1.5x10(-6)M. For binding to the dihidropiridine calcium antagonist binding sites, Ki were: 4.9x10(-5)M for propinox and 2.2x10(-7)M for verapamil. For the phenylakylamine binding sites Ki were: 5.0x10(-6)M for propinox and 3.5x10(-8)M for verapamil. For the benzothiacepine binding sites, Ki for propinox was 5.2x10(-6)M. The following may be concluded: 1- The antispasmodic activity of propinox in isolated human galbladder was was comparatively less potent than of atropine and more potent than those verapamil and (-) scopolamine-n-butyl bromide. 2- Propinox showed binding to muscarinic and calcium receptors that can be related to its antisplasmodic activity; suggesting that the drug is an antispasmodic with anticholinergic and musculotropic activity. 3.- The dual mechanism of action, anticholinergic and calcium-blocking, would induce synergism of pharmacodynamic effects and minimize adverse events of pure antimuscarinic drugs or calcium antagonists.

Antispasmodic action of propinox on the isolated human gallbladder: possible mechanism of action

Propinox is an antispasmodic drug frequently used in the treatment of disorders of the gastrointestinal tract, the uterus and the galbladder, but little is known about its relaxing activity in gallbladder tissue. The main objective of this study was to determine the antispasmodic activity of propinox, compared to other antispasmodics, in the gallblader and to assess its binding affinity to receptor sites which may be involved in its mechanism of action. Antispasmodic activity of propinox, (-) scopolamine-n-butyl bromide, atropine and verapamil was determined in human gallbladders to reduce the risk of interspecies variability. Inhibitory activities (ED50) of carbachol-induced contraction were: atropine 5.03x10(-8) M>propinox 1.25x10(-7) M> verapamil 6.63x10(-6)M> (-) scopolamine-n-butyl1 bromide 5.4x10(-5) M. pD2 for propinox was 6.94, indicating non competitive inhibition of carbachol action. Radioligand binding studies were performed to determine if the antisplasmodic action of the drug involved binding to muscarinic receptors or calciumatagonist sites. The inhibition constant (Ki) of proponix for muscarinic receptors of guinea pig ileum smoth muscle, which contains a mixed M2-M3 receptor population, was 1.6x10(-6) M. Ki for brain muscarinic receptors (M1) was 1.0x10(-4) M, for cardiac receptors (M1) was 1.0x10(-4)M, for receptors (M2) 1.2x10(-6)M and from salivary gland receptors (M3) 1.5x10(-6)M. For binding to the dihidropiridine calcium antagonist binding sites, Ki were: 4.9x10(-5)M for propinox and 2.2x10(-7)M for verapamil. For the phenylakylamine binding sites Ki were: 5.0x10(-6)M for propinox and 3.5x10(-8)M for verapamil. For the benzothiacepine binding sites, Ki for propinox was 5.2x10(-6)M. The following may be concluded: 1- The antispasmodic activity of propinox in isolated human galbladder was was comparatively less potent than of atropine and more potent than those verapamil and (-) scopolamine-n-butyl bromide. 2- Propinox showed binding to muscarinic and calcium receptors that can be related to its antisplasmodic activity; suggesting that the drug is an antispasmodic with anticholinergic and musculotropic activity. 3.- The dual mechanism of action, anticholinergic and calcium-blocking, would induce synergism of pharmacodynamic effects and minimize adverse events of pure antimuscarinic drugs or calcium antagonists. (AU)

Antispasmodic action of propinox on the isolated human gallbladder: possible mechanism of action.

Propinox is an antispasmodic drug frequently used in the treatment of disorders of the gastrointestinal tract, the uterus and the gallbladder, but little is known about its relaxing activity in gallbladder tissue. The main objective of this study was to determine the antispasmodic activity of propinox, compared to other antispasmodics, in the gallbladder and to assess its binding affinity to receptor sites which may be involved in its mechanism of action. Antispasmodic activity of propinox, (-) scopolamine-n-butyl bromide, atropine and verapamil was determined in human gallbladders to reduce the risk of interspecies variability. Inhibitory activities (ED50) of carbachol-induced contraction were: atropine 5.03 x 10(-8) M > propinox 1.25 x 10(-7) M > verapamil 6.63 x 10(-6) M > (-) scopolamine-n-butyl bromide 5.4 x 10(-5) M. pD2 for propinox was 6.94, indicating non competitive inhibition of carbachol action. Radioligand binding studies were performed to determine if the antispasmodic action of the drug involved binding to muscarinic receptors or calciumantagonist sites. The inhibition constant (Ki) of propinox for muscarinic receptors of guinea pig ileum smooth muscle, which contains a mixed M2-M3 receptor population, was 1.6 x 10(-6) M. Ki for brain muscarinic receptors (M1) was 1.0 x 10(-4) M, for cardiac receptors (M2) 1.2 x 10(-6) M and from salivary gland receptors (M3) 1.5 x 10(-6) M. For binding to the dihidropiridine calcium antagonist binding sites, Ki were: 4.9 x 10(-5) M for propinox and 2.2 x 10(-7) M for verapamil. For the phenylalkylamine binding sites Ki were: 5.0 x 10(-6) M for propinox and 3.5 x 10(-8) M for verapamil. For the benzothiacepine binding sites, Ki for propinox was 5.2 x 10(-6) M. The following may be concluded: 1.--The antispasmodic activity of propinox in isolated human gallbladder was comparatively less potent than that of atropine and more potent than those of verapamil and (-) scopolamine-n-butyl bromide. 2.--Propinox showed binding to muscarinic and calcium receptors that can be related to its antispasmodic activity; suggesting that the drug is an antispasmodic with anticholinergic and musculotropic activity. 3.--The dual mechanism of action, anticholinergic and calcium-blocking, would induce synergism of pharmacodynamic effects and minimize adverse events of pure antimuscarinic drugs or calcium antagonists.

Neuropsychiatric observations of proprioceptive sensitivity in motion sickness susceptibility.

The assessment of motion sickness susceptibility is still an unsolved problem, due in part to its unclear etiology. We studied 16 referred patients suffering from "idiopathic motion sickness" and 4 pilots suffering from motion airsickness. All clinical and neurological tests proved negative, including electroencephalograms, electronystagmograms, Doppler studies, and computerized tomography of the brain. Cervical spine X-rays and personality characteristics were assessed. Simultaneously, 35 asymptomatic pilots and pilot applicants were studied as controls. Both groups were exposed to cross-coupled accelerations on a Barany chair at 15 rpm along with 0.5 Hz head flexions. The pathological group showed a straightened cervical curvature as well as a significantly higher degree of malaise (scale of Graybiel and Lackner). Their personalities were highly alexithymic or obsessive compared to the control group (Kruskal-Wallis Test). Alexithymic and obsessive personalities may express their stress reactions and psychic conflicts through somatic signs, such as cervical muscle contractures; consequently, straightening the cervical spine with the subsequent alteration of proprioceptive inputs to the vestibular nuclei may increase motion sickness susceptibility.