The role of neuronal and extraneuronal uptake in the inactivation of 3H-(?)noradrenaline in the rabbit aorta determined by a method relating uptake with amine diffusion in the tissue

1983 ◽  
Vol 324 (3) ◽  
pp. 163-168 ◽  
Author(s):  
M. Henseling
2007 ◽  
Vol 292 (2) ◽  
pp. H1033-H1041 ◽  
Author(s):  
Nitin T. Aggarwal ◽  
Blythe B. Holmes ◽  
Lijie Cui ◽  
Helena Viita ◽  
Seppo Yla-Herttuala ◽  
...  

Endothelium-dependent vasorelaxation of the rabbit aorta is mediated by either nitric oxide (NO) or arachidonic acid (AA) metabolites from cyclooxygenase (COX) and 15-lipoxygenase (15-LO) pathways. 15-LO-1 metabolites of AA, 11,12,15-trihydroxyeicosatrienoic acid (THETA), and 15-hydroxy-11,12-epoxyeicosatrienoic acid (HEETA) cause concentration-dependent relaxation. We tested the hypothesis that in the 15-LO pathway of AA metabolism, 15-LO-1 is sufficient and is the rate-limiting step in inducing relaxations in rabbit aorta. Aorta and rabbit aortic endothelial cells were treated with adenoviruses containing human 15-LO-1 cDNA (Ad-15-LO-1) or β-galactosidase (Ad-β-Gal). Ad-15-LO-1-transduction increased the expression of a 75-kDa protein corresponding to 15-LO-1, detected by immunoblotting with an anti-human15-LO-1 antibody, and increased the production of HEETA and THETA from [14C]AA. Immunohistochemical studies on Ad-15-LO-1-transduced rabbit aorta showed the presence of 15-LO-1 in endothelial cells. Ad-15-LO-1-treated aortic rings showed enhanced relaxation to AA (max 31.7 ± 3.2%) compared with Ad-β-Gal-treated (max 12.7 ± 3.2%) or control nontreated rings (max 13.1 ± 1.6%) ( P < 0.01). The relaxations in Ad-15-LO-1-treated aorta were blocked by the 15-LO inhibitor cinnamyl-3,4-dihydroxy-a-cyanocinnamate. Overexpression of 15-LO-1 in the rabbit aortic endothelium is sufficient to increase the production of the vasodilatory HEETA and THETA and enhance the relaxations to AA. This confirms the role of HEETA and THETA as endothelium-derived relaxing factors.


1987 ◽  
Vol 252 (2) ◽  
pp. H307-H313
Author(s):  
U. Pohl ◽  
R. Busse

We investigated the influence of endothelial cells on the smooth muscle vasodilator effects to sodium nitroprusside (SNP) or Teopranitol (an organic mononitrate) in isolated segments of rabbit aorta and femoral artery. In the femoral artery, the vasodilator responses to both nitrocompounds were significantly higher in the absence of endothelial cells or after pretreatment with the endothelium-derived relaxant factor (EDRF) inhibitor nordihydroguaiaretic acid (NDGA; 10 microM). Moreover, under conditions of stimulated EDRF release (induced by acetylcholine; 30–100 nM) the vasodilator responses to SNP were further attenuated in vessels with intact endothelium. By contrast, in the rabbit aorta, the vasodilator responses to the nitrocompounds were not significantly altered by either endothelium removal or treatment with NDGA. However, in the presence of the EDRF stimulator acetylcholine, the dose-response curve to SNP was shifted to right in the aorta as well. The role of EDRF in the endothelium-mediated attenuation of the dilator potency of SNP was further investigated by using EDRF released from cultured (bovine aortic) endothelial cells. The dilator effects of SNP were compared in endothelium denuded femoral or aortic segments in the presence or absence of EDRF. The vasodilator effects of SNP in both types of arteries were significantly reduced in the presence of EDRF. We conclude that EDRF attenuates the arterial vasodilation induced by SNP and Teopranitol. The results further suggest that endothelial cells exhibit a greater basal release of EDRF in the femoral artery than in the aorta, since under unstimulated conditions an EDRF-induced attenuation was seen only in femoral and not in aortic segments.


1994 ◽  
Vol 266 (2) ◽  
pp. H590-H596 ◽  
Author(s):  
I. R. Hutcheson ◽  
T. M. Griffith

We have investigated the role of Ca(2+)- and ATP-sensitive K+ channels (KCa and KATP, respectively) in flow- and agonist-stimulated release of endothelium-derived relaxing factor (EDRF). Segments of rabbit abdominal aorta, perfused at constant flow with buffer containing indomethacin, were used as a source of EDRF in cascade bioassay, and responses to endothelium-dependent agonists were studied isometrically in rings of the same tissue in the absence of flow. Apamin, charybdotoxin (ChTX), and tetraethylammonium (TEA) were used to block a variety of low, medium, and high conductance KCa channels, and glibenclamide was used to block KATP channels. The effects of flow pulsatility were studied at pulse frequencies ranging from 0.15 to 9.75 Hz, and time-averaged shear stress was manipulated by adding dextran (80,000 mol wt) to the perfusate to increase its viscosity. Frequency-related EDRF release was maximal at approximately 5 Hz and attenuated by apamin, TEA, and ChTX, but not by glibenclamide. EDRF release stimulated by increased viscosity was attenuated by TEA, ChTX, and glibenclamide, but not by apamin. In marked contrast, EDRF release stimulated by acetylcholine and ATP was unaffected by blockade of either KCa or KATP channels. We conclude that a spectrum of KCa channel subtypes mediates endothelial transduction of the oscillatory component of pulsatile flow and that KATP channels may be additionally involved in the transduction of time-averaged shear stress. In contrast, agonist-stimulated endothelium-dependent relaxation is independent of K+ channel activation in rabbit aorta.


2000 ◽  
Vol 14 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Esra K. Ataik ◽  
Ayşe S. Şahin ◽  
Mehmet Kiliç ◽  
Necdet Doğan

1997 ◽  
Vol 30 (4) ◽  
pp. 504-509 ◽  
Author(s):  
Taro Komuro ◽  
Soichi Miwa ◽  
Xiao-Feng Zhang ◽  
Tetsuya Minowa ◽  
Taijiro Enoki ◽  
...  

1982 ◽  
Vol 60 (12) ◽  
pp. 1580-1583 ◽  
Author(s):  
D. Regoli ◽  
J. Mizrahi ◽  
P. D'Orléans-Juste ◽  
S. Caranikas

Bradykinin (BK) and des-Arg9-BK were used to determine whether the stimulatory and inhibitory actions of the kinins in various isolated vessels require the presence of endothelium and may be mediated by arachidonic acid metabolites. It was found that the presence of intact endothelium is required only for the relaxation of the dog common carotid artery in response to bradykinin. Stimulatory actions of both BK and des-Arg9-BK in arterial (rabbit aorta) and venous (rabbit jugular and mesenteric vein) smooth muscle do not require the presence of endothelium. Inhibition of the arachidonic acid cascade at various levels affects the relaxing action of acetylcholine (rabbit aorta and dog common carotid artery) while being inactive against both the relaxing (dog common carotid artery) and contractile actions (rabbit aorta, rabbit jugular and mesenteric veins) of bradykinin and des-Arg9-BK. Inhibitors of the arachidonic acid cascade also do not affect the inhibitory action of isopropylnoradrenaline on the rabbit aorta. The present results indicate that stimulant actions of kinins in isolated vascular smooth muscles do not require the presence of endothelium. Endothelium is required for the inhibitory actions of acetylcholine and bradykinin but not for that of isopropylnoradrenaline on the dog carotid artery. Moreover, the inhibition of arachidonic acid metabolism only affects the response of isolated vessels to acetylcholine. The present results suggest that several mechanisms may be involved in the inhibition of vascular tone by vasodilators.


2002 ◽  
Vol 282 (3) ◽  
pp. C560-C566 ◽  
Author(s):  
Sandeep Gupta ◽  
Eugene Chough ◽  
Jennifer Daley ◽  
Peter Oates ◽  
Keith Tornheim ◽  
...  

Nitric oxide (NO) plays an important role in the control of numerous vascular functions including basal Na+-K+-ATPase activity in arterial tissue. Hyperglycemia inhibits Na+-K+-ATPase activity in rabbit aorta, in part, through diminished bioactivity of NO. The precise mechanism(s) for such observations, however, are not yet clear. The purpose of this study was to examine the role of superoxide in modulating NO-mediated control of Na+-K+-ATPase in response to hyperglycemia. Rabbit aorta incubated with hyperglycemic glucose concentrations (44 mM) demonstrated a 50% reduction in Na+-K+-ATPase activity that was abrogated by superoxide dismutase. Hyperglycemia also produced a 50% increase in steady-state vascular superoxide measured by lucigenin-enhanced chemiluminescence that was closely associated with reduced Na+-K+-ATPase activity. Specifically, the hyperglycemia-induced increase in vascular superoxide was endothelium dependent, inhibited by l-arginine, and stimulated by N ω-nitro-l-arginine. Aldose reductase inhibition with zopolrestat also inhibited the hyperglycemia-induced increase in vascular superoxide. In each manipulation of vascular superoxide, a reciprocal change in Na+-K+-ATPase activity was observed. Finally, a commercially available preparation of Na+-K+-ATPase was inhibited by pyrogallol, a superoxide generator. These data suggest that hyperglycemia induces an increase in endothelial superoxide that inhibits the stimulatory effect of NO on vascular Na+-K+-ATPase activity.


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