In-vitro characterization of the pharmacological effects induced by (–)-α-bisabolol in rat smooth muscle preparations

2012 ◽  
Vol 90 (1) ◽  
pp. 23-35 ◽  
Author(s):  
Rodrigo J.B. de Siqueira ◽  
Walter B.S. Freire ◽  
Alfredo A. Vasconcelos-Silva ◽  
Patrícia A. Fonseca-Magalhães ◽  
Francisco J.B. Lima ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Biologically Active ◽  
Pharmacological Effects ◽  
Bladder Tissue ◽  
In Vitro Characterization ◽  
Voltage Dependent ◽  
Spontaneous Contractions

The present study deals with the pharmacological effects of the sesquiterpene alcohol (–)-α-bisabolol on various smooth-muscle preparations from rats. Under resting tonus, (–)-α-bisabolol (30–300 µmol/L) relaxed duodenal strips, whereas it showed biphasic effects in other preparations, contracting endothelium-intact aortic rings and urinary bladder strips, and relaxing these tissues at higher concentrations (600–1000 µmol/L). In preparations precontracted either electromechanically (by 60 mmol/L K+) or pharmacomechanically (by phenylephrine or carbachol), (–)-α-bisabolol showed only relaxing properties. The pharmacological potency of (–)-α-bisabolol was variable, being higher in mesenteric vessels, whereas it exerted relaxing activity with a lesser potency on tracheal or colonic tissues. In tissues possessing spontaneous activity, (–)-α-bisabolol completely decreased spontaneous contractions in duodenum, whereas it increased their amplitude in urinary bladder tissue. Administered in vivo, (–)-α-bisabolol attenuated the increased responses of carbachol in tracheal rings of ovalbumin-sensitized rats challenged with ovalbumin, but was without effect in the decreased responsiveness of urinary bladder strips in mice treated with ifosfamide. In summary, (–)-α-bisabolol is biologically active in smooth muscle. In some tissues, (–)-α-bisabolol preferentially relaxed contractions induced electromechanically, especially in tracheal smooth muscle. The findings from tracheal rings reveal that (–)-α-bisabolol may be an inhibitor of voltage-dependent Ca2+ channels.

Inhibition of dihydropyridine-sensitive calcium entry in hypoxic relaxation of airway smooth muscle

1995 ◽  
Vol 268 (2) ◽  
pp. L201-L206 ◽  
Author(s):  
C. Vannier ◽  
T. L. Croxton ◽  
L. S. Farley ◽  
C. A. Hirshman
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Muscle Tone ◽  
Bay K 8644 ◽  
O2 Concentration ◽  
Voltage Dependent ◽  
Progressive Hypoxia ◽  
Carbamyl Choline

Hypoxia dilates airways in vivo and reduces active tension of airway smooth muscle in vitro. To determine whether hypoxia impairs Ca2+ entry through voltage-dependent channels (VDC), we tested the ability of dihydropyridines to modulate hypoxia-induced relaxation of KCl- and carbamyl choline (carbachol)-contracted porcine bronchi. Carbachol- or KCl-contracted bronchial rings were exposed to progressive hypoxia in the presence or absence of 1 microM BAY K 8644 (an L-type-channel agonist). In separate experiments, rings were contracted with carbachol or KCl, treated with nifedipine (a VDC antagonist), and finally exposed to hypoxia. BAY K 8644 prevented hypoxia-induced relaxation in KCl-contracted bronchi. Nifedipine (10(-5) M) totally relaxed KCl- contracted bronchi. Carbachol-contracted bronchi were only partially relaxed by nifedipine but were completely relaxed when the O2 concentration of the gas was reduced from 95 to 0%. These data indicate that hypoxia can reduce airway smooth muscle tone by limiting entry of Ca2+ through a dihydropyridine-sensitive pathway, but that other mechanisms also contribute to hypoxia-induced relaxation of carbachol-contracted bronchi.

In vitro and in vivo relaxation of urinary bladder smooth muscle by the selective myosin II inhibitor, blebbistatin

2011 ◽  
Vol 107 (2) ◽  
pp. 310-317 ◽  
Author(s):  
Xinhua Zhang ◽  
Dwaraka Srinivasa R. Kuppam ◽  
Arnold Melman ◽  
Michael E. DiSanto
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Myosin Ii ◽  
Bladder Smooth Muscle ◽  
Urinary Bladder Smooth Muscle

Active Biaxial Mechanical Properties of Bladder Wall Tissue

2003 ◽  
Author(s):  
Jiro Nagatomi ◽  
Michael B. Chancellor ◽  
Michael S. Sacks
Keyword(s):  
Mechanical Properties ◽  
Smooth Muscle ◽  
Urinary Bladder ◽  
Muscle Tone ◽  
Bladder Wall ◽  
Upper Urinary Tract ◽  
Biaxial Stress ◽  
Bladder Tissue ◽  
Biaxial Mechanical Properties

The urinary bladder is a smooth muscle organ whose main functions are to store and to void urine. Since the most important aspect of the storage function of the bladder is to maintain low intravesical pressure in order to protect the upper urinary tract from backflow of urine, the compliance of the bladder wall is one of the key functional paramters to assess the health of this organ. Previously, our laboratory reported, for the first time, the biaxial mechanical properties of bladder wall tissue in the inactive state (in the absence of calcium in the testing bath solution and thus smooth muscle contraction was abolished) (Gloeckner et al. 2002). The bladder in vivo, however, normaly exhibits passive smooth muscle tone during filling and active contraction during voiding. Therefore, in order to completely characterize the bladder tissue mechanical behaviors, it is necessary to examine the load-deformation relationship of the bladder under the passive and active states. In the present study, a novel experimental model was designed to allow collection of biaxial stress-strain data from urinary bladder wall tissue under passive, active and inactive states.

A novel mechanism for vasoconstrictor action of 8-isoprostaglandin F2α on retinal vessels

1998 ◽  
Vol 274 (5) ◽  
pp. R1406-R1416 ◽  
Author(s):  
Isabelle Lahaie ◽  
Pierre Hardy ◽  
Xin Hou ◽  
Haroutioun Hasséssian ◽  
Pierre Asselin ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Retinal Vessels ◽  
Thromboxane Receptor ◽  
Voltage Dependent ◽  
Thromboxane Receptor Antagonist

Using a video-imaging technique, we characterized the effects of 8-isoprostaglandin F2α(8-iso-PGF2α) on retinal vasculature from piglets. 8-Iso-PGF2α potently contracted (EC50 = 5.9 ± 0.5 nM) retinal vessels. These effects were completely antagonized by the cyclooxygenase inhibitor indomethacin, the thromboxane synthase blocker CGS-12970, the thromboxane receptor antagonist L-670596, and the putative inhibitor of the non-voltage-dependent receptor-operated Ca2+ pathway SKF-96365; constrictor effects of 8-iso-PGF2α were also partly attenuated by the ETA-receptor blocker BQ-123 and an inhibitor of endothelin-converting enzyme, phosphoramidon, but was negligibly affected by the L-type voltage-gated Ca2+ channel blocker nifedipine. Correspondingly, 8-iso-PGF2αelicited endothelin release from retinal preparations, which was markedly reduced by SKF-96365. 8-Iso-PGF2α also increased thromboxane production in the retina and cultured endothelial cells, but not on retinovascular smooth muscle cells; these effects of 8-iso-PGF2α were blocked by indomethacin, CGS-12970, SKF-96365, and EGTA, but not by nifedipine. 8-Iso-PGF2α also increased Ca2+ transients in retinal endothelial cells, which were inhibited by SKF-96365 and EGTA, but not by nifedipine, whereas in smooth muscle cells U-46619, but not 8-iso-PGF2α, stimulated a rise in Ca2+ transients. Finally, H2O2+ FeCl2 (in vitro) and anoxia followed by reoxygenation (in vivo) stimulated formation of 8-iso-PGF2α in the retina. In conclusion, 8-iso-PGF2α-induced retinal vasoconstriction is mediated by cyclooxygenase-generated formation of thromboxane and, to a lesser extent, by endothelin after Ca2+ entry into cells, possibly through receptor-operated channels. Retinal vasoconstriction to 8-isoprostanes might play a role in the genesis of ischemic retinopathies.

Effect of neurotensin on mechanical and intracellular electrical activity of the canine stomach

1982 ◽  
Vol 243 (5) ◽  
pp. G404-G409
Author(s):  
K. M. Sanders ◽  
P. Schmalz ◽  
J. H. Szurszewski
Keyword(s):  
Smooth Muscle ◽  
Direct Action ◽  
Inhibitory Effect ◽  
Organ Bath ◽  
Circular Smooth Muscle ◽  
Plateau Potential ◽  
Voltage Dependent ◽  
Adrenergic Antagonists ◽  
Spontaneous Contractions

Intracellular microelectrode and standard organ bath techniques were used to study in vitro the effects of neurotensin on the electrical and mechanical activities of canine antral circular smooth muscle. Neurotensin reduced or abolished spontaneous contractions. Muscarinic and adrenergic antagonists and tetrodotoxin did not block the effects of neurotensin, suggesting that the action of neurotensin was due to a direct action on the smooth muscle cell. Although the inhibitory effect of norepinephrine and neurotensin was similar, the effect of neurotensin did not appear to occur by an adrenergic mechanism because alpha- and beta-receptor blockade had no effect. Neurotensin also reduced or abolished contractions stimulated by pentagastrin and acetylcholine. The inhibitory effect of neurotensin on spontaneous acetylcholine- and pentagastrin-stimulated contractions was associated with a decrease in the amplitude and duration of the plateau potential of the gastric action potential. The data suggest that modulation of antral contractions by neurotensin occurs through a voltage-dependent mechanism that operates during the plateau potential.

Smooth muscle cells from human urinary bladder express connexin 43 in vivo and in vitro

2002 ◽  
Vol 20 (4) ◽  
pp. 250-254 ◽  
Author(s):  
Jochen Neuhaus ◽  
Annett Weimann ◽  
Jens-Uwe Stolzenburg ◽  
Hartwig Wolburg ◽  
Lars-Christian Horn ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Smooth Muscle Cells ◽  
Connexin 43 ◽  
Muscle Cells ◽  
Human Urinary Bladder

scholarly journals Rupture of the Urinary Bladder in the Foal

1971 ◽  
Vol 8 (5-6) ◽  
pp. 445-451 ◽  
Author(s):  
J. R. Rooney
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Dorsal Surface ◽  
External Pressure ◽  
Basic Pattern ◽  
Weak Point ◽  
Distended Bladder ◽  
Circular Layer

The normal muscular anatomy of the urinary bladder of the horse is reviewed. The basic pattern is an outer longitudinal and inner circular layer of smooth muscle, except on the dorsal surface where the circular layer is external. This arrangement permits, according to the principles of mechanics, preferential bulging of the dorsal surface. At the time of birth the urachus is functionally closed, or nearly so. During parturition external pressure on the distended bladder may cause dorsal rupture because the urachus is closed, the penile urethra of the male is compressed in the pelvic canal, and the dorsal surface of the bladder is anatomically a weak point. Rupture of the dorsal surface was produced experimentally by simulating the in vivo conditions in vitro.

scholarly journals A Novel Single Compartment In Vitro Model for Electrophysiological Research Using the Perfluorocarbon FC-770

2016 ◽  
pp. 341-348 ◽  
Author(s):  
M. CHOUDHARY ◽  
F. CLAVICA ◽  
R. VAN MASTRIGT ◽  
E. VAN ASSELT
Keyword(s):  
Afferent Nerve ◽  
Nerve Activity ◽  
Bladder Tissue ◽  
Single Compartment ◽  
Organ Systems ◽  
Electrophysiological Studies ◽  
Spontaneous Contractions ◽  
Stimulation Of

Electrophysiological studies of whole organ systems in vitro often require measurement of nerve activity and/or stimulation of the organ via the associated nerves. Currently two-compartment setups are used for such studies. These setups are complicated and require two fluids in two separate compartments and stretching the nerve across one chamber to the other, which may damage the nerves. We aimed at developing a simple single compartment setup by testing the electrophysiological properties of FC-770 (a perfluorocarbon) for in vitro recording of bladder afferent nerve activity and electrical stimulation of the bladder. Perflurocarbons are especially suitable for such a setup because of their high oxygen carrying capacity and insulating properties. In male Wistar rats, afferent nerve activity was recorded from postganglionic branches of the pelvic nerve in vitro, in situ and in vivo. The bladder was stimulated electrically via the efferent nerves. Organ viability was monitored by recording spontaneous contractions of the bladder. Additionally, histological examinations were done to test the effect of FC-770 on the bladder tissue. Afferent nerve activity was successfully recorded in a total of 11 rats. The bladders were stimulated electrically and high amplitude contractions were evoked. Histological examinations and monitoring of spontaneous contractions showed that FC-770 maintained organ viability and did not cause damage to the tissue. We have shown that FC-770 enables a simple, one compartment in vitro alternative for the generally used two compartment setups for whole organ electrophysiological studies.

Magnesium Transport by the Urinary Bladder of the Crab, Cancer Magister

1980 ◽  
Vol 85 (1) ◽  
pp. 187-201
Author(s):  
CHARLES W. HOLLIDAY
Keyword(s):  
Urinary Bladder ◽  
Sea Water ◽  
Serum Magnesium ◽  
Cancer Magister ◽  
Bladder Tissue ◽  
Eyestalk Ablation ◽  
Antennal Gland ◽  
Bladder Cell

1. Anuric crabs, Cancer magister, in 100% sea water lose most of their ability to regulate serum magnesium levels below that of the external medium, indicating that the antennal gland is the site of most of the crab's hypo-regulatory ability. 2. In vitro measurement of unidirectional fluxes of 28Mg across tissue from the urinary bladder (the terminal element of the antennal gland) showed significant, serosa-to-lumen (SL) net flux of 0.280 ± 0.059 μequiv cm–2 h–1 which was greatly reduced by 5 mM ouabain. Based on the calculated surface area of the bladder in the crab, the net SL flux of magnesium in vitro sufficient to account for the in vivo rate of magnesium excretion by the antennal gland. Bladder tissue from magnesium-depleted crabs which had stopped concentrating magnesium in the urine did not show a significant, net SL flux of 28Mg in vitro. 3. It is speculated that magnesium enters the bladder cell by a sodium-coupled process at the serosal border and is actively transported into the urine at the luminal border. 4. Eyestalk ablation caused no significant changes in urinary rate or magnesium levels in serum or urine; thus neurosecretory centres in the eyestalk are apparently not involved in control of magnesium secretion by the antennal gland. 5. Large, nearly equal, net effluxes of 22Na (1.33 ± 0.19 μequiv cm–2 h–1, ouabain-insensitive) and 36Cl (1.26 ± 0.34 μequiv cm–2 h–1) from the urine were measured in bladder preparations in vitro. It is speculated that this net efflux of salt may be the driving force for fluid reabsorption from the urine by the antennal gland.

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