A comparison of the inhibitory effect of cinnarizine and papaverine on the noradrenaline- and calcium-evoked contraction of isolated rabbit aorta and mesenteric arteries

1979 ◽  
Vol 53 (3) ◽  
pp. 281-288 ◽  
Author(s):  
André Broekaert ◽  
Théophile Godfraind
1986 ◽  
Vol 250 (1) ◽  
pp. C171-C174 ◽  
Author(s):  
K. D. Meisheri ◽  
C. J. Taylor ◽  
H. Saneii

The effects of a synthetic atrial peptide (atriopeptin II; AP II) on the agonist-induced intracellular Ca2+ release was examined in the isolated rabbit aorta. The agonist-induced phasic contraction in a Ca2+-free physiological salt solution containing 2 mM ethyleneglycol-bis(beta-aminoethyl-ether)-N,N'-tetraacetic acid (EGTA-PSS) was used as an indicator of the intracellular Ca2+ release. The addition of AP II (10(-9)-10(-7) M) for 15 min to the tissue during the EGTA-PSS exposure caused a dose-dependent inhibition of norepinephrine (NE; 10(-6) M)-induced phasic contraction. The half-maximal inhibiting concentration of AP II was 3 X 10(-9) M, with 10(-7) M AP II causing 91% inhibition. This was confirmed by studying the inhibitory effect of AP II (10(-7) M) on NE-stimulated 45Ca efflux. Furthermore, the internal Ca2+ release by histamine (10(-5) M) and caffeine (25 mM), both of which share this internal Ca2+ pool with NE, was also inhibited by AP II. Thus AP II appears to be a potent inhibitor of the intracellular Ca2+ release that is utilized by various agonists for the activation of vascular smooth muscle. This may be an important mechanism by which AP II produces relaxation of blood vessels.


1984 ◽  
Vol 51 (01) ◽  
pp. 075-078 ◽  
Author(s):  
R G Schaub ◽  
C A Simmons

SummaryTwenty-seven adult male New Zealand rabbits (3–4 kgs) were used in this study. Six rabbits received vehicle, 3 groups of 6 each received doses of 4,5-bis(p-methoxyphenyl)-2-(trifluoromethyl)- thiazole, (U-53,059), at 0.3 mg/kg, 3.0 mg/kg and 30.0 mg/kg/day respectively. Drug and vehicle doses were given orally each day starting 3 days before balloon injury and continuing for the entire 2 week time period. Three rabbits were used as nontreated sham controls. In the vehicle and U-53,059 treated groups aortae were denuded of endothelial cells by balloon catheter injury. Two weeks after injury platelet aggregation to collagen was measured and the aortae removed for analysis of surface characteristics by scanning electron microscopy and lesion size by morphometry. All doses of U-53,059 inhibited platelet aggregation. The 3.0 and 30.0 mg/kg groups had the greatest inhibitory effect. All balloon injured aortae had the same morphologic characteristics. All vessels had similar extent and intensity of Evan’s blue staining, similar areas of leukocyte/platelet adhesion, and a myointimal cell cover of transformed smooth muscle cells. The myointimal proliferative response was not inhibited at any of the drug doses studied.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Khalid Hussain Janbaz ◽  
Muhammad Farhaj Latif ◽  
Fatima Saqib ◽  
Imran Imran ◽  
M. Zia-Ul-Haq ◽  
...  

Lactuca serriolaL. has traditionally been used in folkloric medicine to manage respiratory, gastrointestinal, and multiple other ailments. The present study was undertaken to explore the effect of methanol extract ofL. serriolaon isolated rabbit tissue preparations, that is, jejunum, trachea, and aorta in an attempt to validate its folkloric use in traditional medicine for gastrointestinal, respiratory, and vascular ailments. The application of the methanol extract to isolated rabbit jejunum preparations exhibited concentration-dependent spasmogenic effect (0.03 to 3.0 mg/mL), but interestingly further increase in concentration (5.0 mg/mL) resulted in complete spasmolytic effect. The pretreatment of the tissue preparations with atropine (0.1 μM) caused the suppression of the contractile response. Moreover, the same extract also caused relaxation of K+-(80 mM) induced spastic contractions of isolated rabbit jejunum preparations (5.0 mg/mL) and shifted the Ca++dose response curves towards right at concentration range of 0.3–1.0 mg/mL. Similarly, the extract application to isolated rabbit tracheal preparations relaxed the carbachol-(1 μM) induced (0.3–1.0 mg/mL) as well as K+-(80 mM) induced contractions (3.0 mg/mL). Furthermore, it relaxed the phenylephrine (1 μM)-induced contractions in isolated rabbit aorta preparations (3.0 mg/mL) and K+(80 mM)-induced contractions (1.0 mg/mL). These effects were found comparable to that of dicyclomine, as an antagonist of muscarinic receptors as well as a possible Ca++channel blocker. The previously mentioned findings may partially justify the folkloric use ofLactuca serriolain the management of conditions pertaining to spasm of intestine, bronchioles, and vasculature.


2008 ◽  
Vol 294 (2) ◽  
pp. H679-H687 ◽  
Author(s):  
Xin Tang ◽  
Nitin Aggarwal ◽  
Blythe B. Holmes ◽  
Hartmut Kuhn ◽  
William B. Campbell

Rabbit 15-lipoxygenase-1 (15-LO-1) oxygenates arachidonic acid (AA) into 15-hydroperoxyeicosatetraenoic acid, which is then converted to the vasodilatory 15-hydroxy-11,12-epoxyeicosatrienoic acid (HEETA) and 11,12,15-trihydroxyeicosatrienoic acid (THETA). We studied the age-dependent expression of the 15-LO-1 in rabbit aorta and its effects on the synthesis of THETA, HEETA, and vasoactivity. Aortas of 1-wk-old rabbits express greater amounts of 15-LO-1 mRNA and protein compared with aortas of 4-, 8-, or 16-wk-old rabbits. The synthesis of THETA and HEETA in the rabbit aorta was also reduced with age. THETA synthesis was maximal in 1-wk-old aortas but decreased in aortas of 4- (42%), 8- (4%), and 16-wk-old (1%) rabbits. Similarly, THETA and HEETA synthesis decreased with age in mesenteric arteries from 1-, 4-, 8-, and 16-wk-old rabbits. The maximum vasorelaxation response to acetylcholine (10−6M) in the presence of indomethacin and nitro-l-arginine decreased in the order of 1 wk (64.5 ± 6.9%), 4 wk (52.6 ± 8.9%), 8 wk (53.0 ± 9.4%), and 16 wk (33.3 ± 6.6%). Similarly, the maximum relaxation to AA (3 × 10−4M) decreased with age in the order of 1 wk (60.4 ± 8.9%), 4 wk (56.3 ± 5.8%), 8 wk (41.8 ± 12.3%), and 16 wk (28.9 ± 1.6%). In contrast, the vasorelaxation to sodium nitroprusside was not significantly altered by age. These data indicate that aortic 15-LO-1 expression and activity are downregulated with aging in rabbits. This decrease is paralleled by the reduced synthesis of vasoactive THETA and HEETA and aortic relaxations to acetylcholine and AA.


1982 ◽  
Vol 84 (3-4) ◽  
pp. 233-235 ◽  
Author(s):  
C. Cauvin ◽  
R. Loutzenhiser ◽  
O. Hwang ◽  
C. Van Breemen

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