Vasorelaxant Action of N-p-Nitrophenylmaleimide in the Isolated Rat Mesenteric Artery

2010 ◽  
Vol 65 (7-8) ◽  
pp. 451-457 ◽  
Author(s):  
Eurica Ribeiro ◽  
Fabíola F. Furtado ◽  
Vânia F. Noldin ◽  
Rogério Corrêa ◽  
Valtir Cechinel-Filho ◽  
...  
Keyword(s):  
Mesenteric Artery ◽  
Inhibitory Effect ◽  
Isometric Tension ◽  
Free Medium ◽  
Response Curves ◽  
Tetraethylammonium Bromide ◽  
Relaxant Effect ◽  
Vasorelaxant Effect ◽  
Resting Tension ◽  
Rat Mesenteric Artery

The vasorelaxant response of N-p-nitrophenylmaleimide (4-NO2-NPM) was evaluated. The mesenteric rings (1 - 2 mm i.d.) were suspended by cotton thread for isometric tension recordings in a Tyrode’s solution at 37 °C and gassed with a mixture of 95% O2 and 5% CO2, under a resting tension of 0.75 g. 4-NO2-NPM induced relaxation in mesenteric rings pre-contracted with phenylephrine (Phe; 10 μM, pD2 = 6.7 ± 0.3) or KCl (80 mM, pD2 = 3.9 ± 0.2). This effect was significantly attenuated after removal of the vascular endothelium, NG-nitro L-arginine methyl ester (L-NAME; 100 μM), atropine (1 μM), indomethacin (10 μM), L-NAME + indomethacin or 1H-[1,2,3]oxadiazolo[4,3-α]quinoxalin-1-one (ODQ; 10 μM). LArginine (1 mM) reversed the inhibitory effect of L-NAME. In endothelium-intact preparations pre-incubated with 20 mM KCl, tetraethylammonium bromide (TEA; 1 mM) or glibenclamide (Glib; 10 μM), the vasorelaxant effect was significantly attenuated when compared to controls (endothelium intact). In denuded rings, separate incubation with 20 mM KCl, TEA or Glib did not change the relaxation when compared with that obtained in denuded rings. 4-NO2-NPM inhibited in a concentration-dependent and non-competitive manner the concentration-response curves induced by CaCl2. In calcium-free medium, the transient contractions induced by Phe (10 μM) or caffeine (20 mM) were inhibited. The relaxant effect induced by 4-NO2 -NPM appeared to be due to endothelial muscarinic receptors activation, NO and prostacyclin release and KATP and BKCa (Ca2+-activated K+ channels) endotheliumdependent activation. Inhibition of the Ca2+ influx and inhibition of the Ca2+ release from intracellular IP3- and caffeine-sensitive stores are also involved in the vasorelaxation

scholarly journals Vasorelaxant Effect Induced by the Essential Oil of Ocotea duckei Vattimo Leaves and Its Main Constituent, Trans-caryophyllene, in Rat Mesenteric Artery

2020 ◽  
pp. 31-39
Author(s):  
Tays Amanda Felisberto Gonçalves ◽  
Renildo Moura da Cunha ◽  
Dionatas Ulises de Oliveira Meneguetti ◽  
Marcio Roberto Viana Santos ◽  
José Maria Barbosa- Filho ◽  
...  
Keyword(s):  
Essential Oil ◽  
Mesenteric Artery ◽  
Calcium Release ◽  
Mesenteric Arteries ◽  
Dependent Manner ◽  
Main Constituent ◽  
Response Curves ◽  
Vasorelaxant Effect ◽  
Rat Mesenteric Artery ◽  
Isolated Rat

Aims: To evaluate the vasorelaxant effect induced by the essential oil of the leaves of O. duckei Vattimo (ODEO) and its main constituent, trans-caryophyllene, in rat superior mesenteric arteries. Methodology: Isolated rat superior mesenteric rings were suspended by cotton threads for isometric tension recordings in Tyrode’s solution at 37ºC, gassed with 95% O2 and 5% CO2 and different ODEO concentrations (0.1-300 μg/mL) or trans-caryophyllene (1-1000 μg/mL) were added cumulatively to the organ baths. Results: Vasorelaxant effect induced by the essential oil of Ocotea duckei leaves (ODEO) and its main constituent, trans-caryophyllene (60.54 %), was evaluated in this work. In intact isolated rat superior mesenteric rings ODEO (0.1-300 μg/mL, n=6) induced concentration-dependent relaxation of tonus induced by phenylephrine (10 µM) or K+-depolarizing solution (KCl 80 mM) (IC50=31±5, 5±0.4 µg/mL, respectively, n=6). The relaxations of phenylephrine-induced contractions were not significantly attenuated after removal of the vascular endothelium (IC50=25±5 µg/mL). ODEO antagonized the concentration-response curves to CaCl2 (10-6-3x10-2 M) and Bay K 8644 (10-10-3x10-6 M). Furthermore, in nominally without calcium solution, ODEO significantly inhibited, in a concentration-dependent manner, transient contractions induced by 10 µM phenylephrine or 20 µM caffeine. Trans-caryophyllene induced vasorelaxations, however, this effect was 18.6 times less potent when compared to ODEO-induced vasorelaxations. Conclusion: The relaxant effect induced by ODEO in rat superior mesenteric artery rings is endothelium-independent and seems to be related to both, inhibition of Ca2+ influx through L-type voltage-gated Ca2+-channels sensitive to dihydropyridines and inhibition of the calcium release from intracellular IP3-and caffeine-sensitive stores.

scholarly journals Relaxant Effect of Monoterpene (−)-Carveol on Isolated Human Umbilical Cord Arteries and the Involvement of Ion Channels

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2681 ◽  
Author(s):  
Renata Evaristo Rodrigues da Silva ◽  
Andressa de Alencar Silva ◽  
Luís Pereira-de-Morais ◽  
Nayane de Sousa Almeida ◽  
Marcello Iriti ◽  
...  
Keyword(s):  
Umbilical Artery ◽  
Biological Activities ◽  
Isometric Tension ◽  
Human Umbilical Cord ◽  
Free Medium ◽  
Relaxant Effect ◽  
Vasorelaxant Effect ◽  
Vasorelaxant Activity ◽  
Umbilical Arteries ◽  
Smooth Muscle Contractions

Carveol is a monoterpene present in the structure of many plant products. It has a variety of biological activities: antioxidant, anticancer and vasorelaxation. However, studies investigating the effect of monoterpenoids on human vessels have not yet been described. Thus, the present study aimed to characterize the effect of (−)-carveol on human umbilical arteries (HUAs). HUA ring preparations were isolated and subjected to isometric tension recordings of umbilical artery smooth muscle contractions. (−)-Carveol exhibited a significant vasorelaxant effect on KCl and 5-HT-induced contractions, obtaining EC50 values of 344.25 ± 8.4 and 175.82 ± 4.05 µM, respectively. The participation of calcium channels in the relaxation produced by (−)-carveol was analyzed using vessels pre-incubated with (−)-carveol (2000 µM) in a calcium-free medium, where the induction of contractions was abolished. The vasorelaxant effect of (−)-carveol on HUAs was reduced by tetraethylammonium (TEA), which increased the (−)-carveol EC50 to 484.87 ± 6.55 µM. The present study revealed that (−)-carveol possesses a vasorelaxant activity in HUAs, which was dependent on the opening of calcium and potassium channels. These results pave the way for further studies involving the use of monoterpenoids for the vasodilatation of HUAs. These molecules have the potential to treat diseases such as pre-eclampsia, which is characterized by resistance in umbilical arteries.

Isoproterenol attenuates myosin phosphorylation and contraction of tracheal muscle

1989 ◽  
Vol 66 (5) ◽  
pp. 2017-2022 ◽  
Author(s):  
K. Obara ◽  
P. de Lanerolle
Keyword(s):  
Light Chain ◽  
Myosin Light Chain ◽  
Isometric Force ◽  
Smooth Muscles ◽  
Inhibitory Effect ◽  
Isometric Tension ◽  
Myosin Light Chain Phosphorylation ◽  
Response Curves ◽  
Shortening Velocity ◽  
Myosin Phosphorylation

The effects of isoproterenol on isometric force, unloaded shortening velocity, and myosin phosphorylation were examined in thin muscle bundles (0.1–0.2 mm diam) dissected from lamb tracheal smooth muscle. Methacholine (10(-6) M) induced rapid increases in isometric force and in phosphorylation of the 20,000-Da myosin light chain. Myosin phosphorylation remained elevated during steady-state maintenance of isometric force. The shortening velocity peaked at 15 s after stimulation with methacholine and then declined to approximately 45% of the maximal value by 3 min. Isoproterenol pretreatment inhibited methacholine-stimulated myosin light chain phosphorylation, shortening velocity, and force during the early stages of force generation. However, the inhibitory effect of isoproterenol on force and myosin phosphorylation is proportionally greater than that on shortening velocity. Isoproterenol pretreatment also caused a rightward non-parallel shift in the methacholine dose-response curves for both isometric tension and myosin light chain phosphorylation. These data demonstrate that isoproterenol attenuates the contractile properties of airway smooth muscles by affecting the rate and extent of myosin light chain phosphorylation, perhaps through a mechanism that involves the synergistic interaction of myosin light chain kinase phosphorylation and Ca2+ metabolism.

scholarly journals Hydrogen peroxide and superoxide anion modulate pregnant human myometrial contractility

Reproduction ◽  
2005 ◽  
Vol 130 (4) ◽  
pp. 539-544 ◽  
Author(s):  
Averil Y Warren ◽  
Balwir Matharoo-Ball ◽  
Robert W Shaw ◽  
Raheela N Khan
Keyword(s):  
Hydrogen Peroxide ◽  
Channel Blocker ◽  
Inhibitory Effect ◽  
Isometric Tension ◽  
Human Myometrium ◽  
Response Curves ◽  
Tetraethylammonium Chloride ◽  
Myometrial Contractility ◽  
Macromolecular Damage ◽  
Maximal Reduction

Reactive oxygen species (ROS) have the propensity to cause macromolecular damage with consequent modification of cellular function. We investigated the effects of two particular oxidants, superoxide (O2−) anions and hydrogen peroxide (H2O2), on oxytocin-induced myometrial contractility using biopsies from women undergoing Caesarean section at term gestation. Isometric tension recordings were performed and concentration–response curves derived after addition of test agents. A maximal reduction in myometrial contractility to 27.2 ± 4.5% of control was observed followed application of H2O2. The enzyme scavenger catalase (CAT) reduced the inhibitory effect of H2O2but had little effect at 10-fold lower concentrations. Addition of dialysed xanthine oxidase ± hypoxanthine significantly inhibited contractility to 23.8.0 ± 4.2% compared with control. Pre-incubation with superoxide dismutase and CAT diminished this effect. The non-specific potassium channel blocker, tetraethylammonium chloride (1 mM), had no effect on myometrial contractility. We conclude that human myometrium is susceptible to the effects of ROS, which may be produced by reperfusion–ischaemic episodes during labour. Our findings could, in part, explain the weak or prolonged depression of contractions characteristic of myometrial dysfunction culminating in difficult labours.

Garcinielliptone FC, a polyisoprenylated benzophenone fromPlatonia insignisMart., promotes vasorelaxant effect on rat mesenteric artery

2014 ◽  
Vol 28 (12) ◽  
pp. 923-927 ◽  
Author(s):  
Daniel Dias Rufino Arcanjo ◽  
Joaquim Soares da Costa-Júnior ◽  
Lucas Henrique Porfírio Moura ◽  
Alexandre Barros Falcão Ferraz ◽  
Raíssa Rebés Rossatto ◽  
...  
Keyword(s):  
Mesenteric Artery ◽  
Vasorelaxant Effect ◽  
Rat Mesenteric Artery

scholarly journals Vasorelaxation in rat pulmonary artery induced by the monoterpene thymol: evaluation of the endothelium derived relaxant factors dependence

2021 ◽  
Vol 10 (4) ◽  
pp. e29010413971
Author(s):  
Renata de Souza Sampaio ◽  
Giuliana Amanda de Oliveira ◽  
Luiz Henrique César Vasconcelos ◽  
Paula Benvindo Ferreira ◽  
Maria da Conceição Correia Silva ◽  
...  
Keyword(s):  
Essential Oil ◽  
Pulmonary Artery ◽  
Inhibitory Effect ◽  
Tonic Contraction ◽  
Relaxant Effect ◽  
Vasorelaxant Effect ◽  
Cholinergic Pathway

Thymol and carvacrol are the main compounds found in Lippia mycrophylla essential oil (LM-OE) and have presented some spasmolytic effects. This work was designed to explore a possible vasorelaxant effect of LM-OE and its major monoterpenes constituents on rat pulmonary artery. For that, the organ was in vitro stimulated with phenylephrine (Phe) 3 mM and over the tonic contraction the relaxant effect of LM-OE, carvacrol and thymol was observed in both intact and denuded-endothelium. Moreover, atropine, L-NAME, indomethacin, 2,3-O-isopropylidene adenosine, H-89 and Y-27632 were incubated before the relaxant curve of thymol over Phe-tonic contraction. Furthermore, the effects of thymol on KCl 30 or 80 mM and S-(−)-Bay K8644-induced tonic contractions were evaluated, as well as its inhibitory effect on CaCl2-induced cumulative contractions. LM-OE, carvacrol and thymol presented relaxant effect on pulmonary artery, thymol was the most potent and its relaxant potency in intact-endothelium preparations was reduced by atropine, L-NAME, indomethacin, 2,3-O-isopropylidene adenosine and H-89, despite there was not change on its maximum relaxat effect. Also, the monoterpene relaxed equipotently KCl 30 or 80 mM pre-contracted pulmonary artery, antagonized CaCl2-induced cumulative contractions and relaxed S-(−)-Bay K8644 pre-contracted organ. Ultimately, thymol relaxant potency was not modified by Y-27632. Therefore, thymol acts by endothelium-dependent and independent mechanisms, possibly positively modulating the endothelial cholinergic pathway, prostanoids release and further activation of AC/PKA and also inhibiting Ca2+ influx through CaV.

Analysis of the Mechanisms Underlying the Vasorelaxant Action of Coptisine in Rat Aortic Rings

2012 ◽  
Vol 40 (02) ◽  
pp. 309-320 ◽  
Author(s):  
Li-Li Gong ◽  
Lian-Hua Fang ◽  
Hai-Lin Qin ◽  
Yang Lv ◽  
Guan-Hua Du
Keyword(s):  
Dependent Manner ◽  
Free Solution ◽  
Free Medium ◽  
Response Curves ◽  
Concentration Dependent Manner ◽  
Vasorelaxant Effect ◽  
Voltage Dependent ◽  
Endothelium Dependent Relaxation ◽  
External Calcium ◽  
Isolated Rat

The aim of the present study was to evaluate the vasorelaxant effects of coptisine and its possible mechanisms in isolated rat aortic rings. Coptisine was evaluated on isolated rat aortic rings precontracted with norepinephrine (NE) and KCl. The mechanisms were evaluated in the presence or absence of specific pharmacological inhibitors. Coptisine (1 ~ 200 μM) relaxed NE (1 μM) or KCl (60 mM) induced sustained contraction with pEC50 values of 4.49 ± 0.48 and 4.85 ± 0.57 in a concentration dependent manner. Pretreatment with coptisine (10, 50 or 100 μM) also inhibited concentration-response curves to NE and KCl. The vasorelaxant effect of coptisine was attenuated significantly by endothelium removal, and incubation with Nω-nitro-L-arginine methyl ester (L-NAME, 100 μM), methylene blue (10 μM) and indomethacin (5 μM) partially reduced the vasorelaxant effect of coptisine. In endothelium-denuded rings, the vasorelaxant effect of coptisine was reduced significantly by 4-aminopyridine (4-AP, 100 μM), but not glibenclamide (10 μM) ortetraethylammonium (TEA, 5 mM). Coptisine also reduced NE-induced transient contraction in Ca2+ -free solution, and inhibited contraction induced by increasing external calcium in Ca2+ -free medium plus 60 mM KCl. It was concluded that coptisine induced both endothelium-dependent and -independent relaxation in rat aortic rings. The NO-cGMP mediated pathway may be involved in the endothelium-dependent relaxation and in the activation of voltage-dependent K+ channels, contributing in part to the endothelium-independent relaxation bycoptisine. Coptisine also blocks extracellular Ca2+ influx by interacting with both voltage- and receptor-operated Ca2+ channels.

Relaxant and contractile responses of detrusor muscle strips obtained from bladder outlet-obstructed rats treated with doxazosin enantiomers

2011 ◽  
Vol 89 (12) ◽  
pp. 883-890 ◽  
Author(s):  
Miao Wang ◽  
Xue-Jiao Ren ◽  
Qing-Hua Zhao ◽  
Li-Xin Lin ◽  
Xue Wang ◽  
...  
Keyword(s):  
Mesenteric Artery ◽  
Outlet Obstruction ◽  
Detrusor Muscle ◽  
Bladder Smooth Muscle ◽  
Response Curves ◽  
Prostate Hyperplasia ◽  
Beneficial Effects ◽  
Chiral Carbon ◽  
Rat Mesenteric Artery ◽  
Relaxant Response

(–)Doxazosin, one of (±)doxazosin enantiomers, was speculated to have a pharmacological enantioselectivity between the cardiovascular system and the urinary system by comparison with (+)doxazosin. Therefore, to evaluate the potential benefits of (–)doxazosin in the treatment of benign prostate hyperplasia, we compared the effects of the 3 agents, using rat mesenteric artery preparations and obstructed bladder strips. Concentration–response curves for carbachol (contractile response) and isoprenaline (relaxant response) in detrusor muscle strips of the bladder outlet obstruction (BOO) rats were shifted to the left, with significant increases in the Emax values, and significant decreases in the EC50 values by comparison with the sham-operated rats (P < 0.05, n = 10). The enhanced responses in detrusor muscle strips of the BOO rats treated with (±)doxazosin and its enantiomers at 3 mg·(kg body mass)–1·day–1 for 2 weeks returned to normal levels, and the 3 agents inhibited the enhanced responses to carbachol and isoprenaline to the same extent. On the other hand, the 3 agents uncompetitively inhibited the vasoconstrictive response curves for NA in the rat isolated mesenteric artery, and the pKB value of (–)doxazosin at vascular α1-adrenoceptors was significantly smaller (P < 0.05, n = 6) than that of (+)doxazosin or (±)doxazosin. In conclusion, although (–)doxazosin inhibits vascular functional α1-adrenoceptors more weakly than (+)doxazosin, both agents equally ameliorate the enhanced responses in detrusor muscle of BOO rats, suggesting that the chiral carbon atom in the molecular structure of doxazosin does not affect its beneficial effects in the bladder smooth muscle of BOO rats.

scholarly journals Effects of abnormal cannabidiol on oxytocin-induced myometrial contractility

Reproduction ◽  
2010 ◽  
Vol 139 (4) ◽  
pp. 783-788 ◽  
Author(s):  
Diarmaid D Houlihan ◽  
Michael C Dennedy ◽  
John J Morrison
Keyword(s):  
Methylene Blue ◽  
Guanylate Cyclase ◽  
Inhibitory Effect ◽  
Isometric Tension ◽  
Tissue Type ◽  
Elective Cesarean Section ◽  
Uterine Contractility ◽  
Response Curves ◽  
Myometrial Contractility

The objective of this study was to investigate the effects of abnormal cannabidiol (abn-cbd) on oxytocin-induced myometrial contractility occurring during pregnancy. Isometric tension recordings were performed in isolated myometrial strips from biopsies obtained at elective cesarean section. The effects of cumulative doses of abn-cbd (10−9–10−5 M) on oxytocin-induced myometrial contractions alone, and on those following pre-incubation with SR 144528, AM 251, methylene blue, and iberiotoxin were measured, and dose–response curves were constructed. The pD2(−log EC50) values and the maximal inhibitory (MMI) values that were achieved were compared for each tissue type. Abn-cbd exerted a potent relaxant effect on oxytocin-induced myometrial contractionsin vitro. Pre-incubation with the guanylate cyclase inhibitor, methylene blue, and the BKCachannel antagonist, iberiotoxin, significantly attenuated this effect (for pD2,P<0.01; for MMI,P<0.01). Abn-cbd exerts a potent inhibitory effect on human uterine contractility. This effect is partially mediated through modulation of guanylate cyclase and activation of BKCachannel activity. These findings have implications for physiologic regulation of myometrial quiescence.

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