Substituted catechols include both natural and synthetic compounds found in the environment and foods. Some of them are flavonoid metabolites formed by the gut microbiota which are absorbed afterwards. Our previous findings showed that one of these metabolites, 4-methylcatechol, exerts potent vasorelaxant effects in rats. In the current study, we aimed at testing of its 22 structural congeners in order to find the most potent structure and to investigate the mechanism of action. 3-methoxycatechol (3-MOC), 4-ethylcatechol, 3,5-dichlorocatechol, 4-tert-butylcatechol, 4,5-dichlorocatechol, 3-fluorocatechol, 3-isopropylcatechol, 3-methylcatechol and the parent 4-methylcatechol exhibited high vasodilatory activities on isolated rat aortic rings with EC50s ranging from ∼10 to 24 μM. Some significant sex-differences were found. The most potent compound, 3-MOC, relaxed also resistant mesenteric artery but not porcine coronary artery, and decreased arterial blood pressure in both male and female spontaneously hypertensive rats in vivo without affecting heart rate. It potentiated the vasodilation mediated by cAMP and cGMP, but did not impact L-type Ca2+-channels. By using two inhibitors, activation of voltage-gated potassium channels (KV) was found to be involved in the mechanism of action. This was corroborated by docking analysis of 3-MOC with the KV7.4 channel. None of the most active catechols decreased the viability of the A-10 rat embryonic thoracic aorta smooth muscle cell line. Our findings showed that various catechols can relax vascular smooth muscles and hence could provide templates for developing new antihypertensive vasodilator agents without affecting coronary circulation.

• MeSH
• aorta thoracica účinky léků   metabolismus   MeSH
• arteriae mesentericae * účinky léků   metabolismus   MeSH
• arteriální tlak účinky léků   MeSH
• draslíkové kanály řízené napětím metabolismus   antagonisté a inhibitory   účinky léků   MeSH
• guanosinmonofosfát cyklický metabolismus   MeSH
• hypertenze farmakoterapie   patofyziologie   metabolismus   MeSH
• katecholy * farmakologie   chemie   MeSH
• koronární cévy účinky léků   metabolismus   MeSH
• krysa rodu rattus MeSH
• modely nemocí na zvířatech MeSH
• myocyty hladké svaloviny účinky léků   metabolismus   MeSH
• potkani inbrední SHR * MeSH
• prasata MeSH
• sexuální faktory MeSH
• simulace molekulového dockingu * MeSH
• svaly hladké cévní účinky léků   metabolismus   MeSH
• vazodilatace * účinky léků   MeSH
• vazodilatancia * farmakologie   chemie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The endothelium contributes to the maintenance of vasodilator tone by releasing endothelium-derived relaxing factors, including nitric oxide (NO). In hypertension, endothelial nitric oxide synthase (eNOS) produces less NO and could be one of the contributing factors to the increased peripheral vascular resistance. Agonist-induced Ca(2+) entry is essential for the activation of eNOS. The transient receptor potential vanilloid type 4 (TRPV4) channel, a Ca(2+)-permeant cation channel, is expressed in the endothelial cells and involved in the regulation of vascular tone. The present study aimed to investigate the role of TRPV4 channel in endothelium-dependent NO-mediated relaxation of the resistance artery in hypertensive rats. Using a wire myograph, relaxation response to the TRPV4 activator, 4alpha-phorbol-12,13-didecanoate (4alphaPDD) was assessed in mesenteric arteries obtained from Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHRs). Compared to WKY, SHR demonstrated a significantly attenuated 4alphaPDD-induced endothelium-dependent NO-mediated relaxation. Immunohistochemical analysis revealed positive staining for TRPV4 in the endothelium of mesenteric artery sections in both WKY and SHR. Furthermore, TRPV4 mRNA and protein expressions in SHR were significantly lower than their expression levels in WKY rats. We conclude that 4alphaPDD-induced endothelium-dependent NO-mediated vasorelaxation is reduced in SHR and downregulation of TRPV4 could be one of the contributing mechanisms.

• MeSH
• arteriae mesentericae účinky léků   metabolismus   patofyziologie   MeSH
• cévní endotel účinky léků   metabolismus   MeSH
• down regulace účinky léků   fyziologie   MeSH
• forboly farmakologie   MeSH
• hypertenze metabolismus   patofyziologie   MeSH
• kationtové kanály TRPV agonisté   metabolismus   MeSH
• krysa rodu rattus MeSH
• orgánové kultury - kultivační techniky MeSH
• potkani inbrední SHR MeSH
• potkani inbrední WKY MeSH
• synthasa oxidu dusnatého, typ III metabolismus   MeSH
• vazodilatace účinky léků   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

SCOPE: The flavonoid quercetin reduces arterial blood pressure in animals and humans but the mechanisms remains elusive. The aim of this study was to test the activity of flavonoid microbial metabolites, which can participate on the final vasorelaxant effect. METHODS AND RESULTS: Both ex vivo (isolated rat thoracic aorta and mesenteric artery) and in vivo (normotensive and spontaneously hypertensive rats) approaches were used in this study. 4-methylcatechol and 3,4-dihydroxyphenylacetic acid (DHPA) had greater vasorelaxant effects on mesenteric artery than 3-(3-hydroxyphenyl)propionic acid, the previously reported metabolite with vasorelaxant effect. In vivo testing confirmed their blood pressure decreasing effect given both as bolus and slow infusion. Their mechanism at molecular level was different. CONCLUSIONS: This study is the first to show that flavonoid metabolites DHPA and 4-methylcatechol decrease arterial blood pressure and hence a mixture of microbial metabolites formed in the gastrointestinal tract may be responsible for or contribute to the effect of orally ingested quercetin.

• MeSH
• antihypertenziva farmakologie   MeSH
• aorta thoracica účinky léků   MeSH
• arteriae mesentericae účinky léků   MeSH
• arteriální tlak účinky léků   MeSH
• hypertenze farmakoterapie   patofyziologie   MeSH
• katecholy farmakologie   MeSH
• kyselina 3,4-dihydroxyfenyloctová farmakologie   MeSH
• modely nemocí na zvířatech MeSH
• potkani inbrední SHR MeSH
• potkani Wistar MeSH
• techniky in vitro MeSH
• vazodilatace účinky léků   MeSH
• vazodilatancia farmakologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The aim of this study was to investigate the effect of high fructose intake associated with moderate increase in adiposity on rat arterial adrenergic responses and their modulation by perivascular adipose tissue (PVAT). After eight-week-lasting substitution of drinking water with 10 % fructose solution in adult normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR), their systolic blood pressure, plasma triglycerides, and relative liver weight were elevated when compared to their respective control groups. Moreover, in SHR, body weight and relative heart weight were increased after treatment with fructose. In superior mesenteric arteries, PVAT exerted inhibitory influence on adrenergic contractile responses and this effect was markedly stronger in control WKY than in SHR. In fructose-administered WKY, arterial adrenergic contractions were substantially reduced in comparison with the control group; this was caused mainly by enhancement of anticontractile action of PVAT. The diminution of the mesenteric arterial contractions was not observed after fructose treatment in SHR. We conclude that the increase in body adiposity due to fructose overfeeding in rats might have prehypertensive effect. However, in WKY it might cause PVAT-dependent and independent reduction in arterial contractile responses to adrenergic stimuli, which could attenuate the pathological elevation in vascular tone.

• MeSH
• adrenergní látky farmakologie   MeSH
• arteriae mesentericae účinky léků   fyziologie   MeSH
• fruktosa aplikace a dávkování   toxicita   MeSH
• hypertenze patofyziologie   MeSH
• krevní tlak účinky léků   fyziologie   MeSH
• krysa rodu rattus MeSH
• náhodné rozdělení MeSH
• potkani inbrední SHR MeSH
• potkani inbrední WKY MeSH
• tuková tkáň krevní zásobení   účinky léků   fyziologie   MeSH
• vazokonstrikce účinky léků   fyziologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Proximal resistance vessels, such as the mesenteric arteries, contribute substantially to the peripheral resistance. The reactivity of resistance vessels to vasoactive substance like natriuretic peptides plays an important role in the regulation of blood pressure. In current study, we investigated the reactivity of mesenteric arteries to atrial natriuretic peptide (ANP), a well known vasodilating factor, in spontaneously hypertensive rats (SHR), as well as the effects of exercise training on it. As a result, ANP-induced vasorelaxation was attenuated in SHR with significantly increased phosphodiesterase type 5 (PDE5), and decreased cGMP/ANP ratio, compared with WKY rats as control. Intriguingly, the decreased reactivity to ANP in SHR was markedly reversed by exercise training. In addition, ANP resistance of in vitro mesenteric arteries was diminished by sildenafil a potent selective inhibitor of PDE5. In conclusion, ANP resistance occurs in resistance vessels of SHR, suggesting predisposition to hypertension, which can be reversed by exercise.

• MeSH
• arteriae mesentericae účinky léků   fyziologie   MeSH
• atriální natriuretický faktor farmakologie   terapeutické užití   MeSH
• hypertenze farmakoterapie   patofyziologie   terapie   MeSH
• kondiční příprava zvířat metody   fyziologie   MeSH
• krevní tlak účinky léků   fyziologie   MeSH
• krysa rodu rattus MeSH
• léková rezistence MeSH
• potkani inbrední SHR MeSH
• potkani inbrední WKY MeSH
• vazodilatace účinky léků   fyziologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

To investigate lisinopril effect on the contribution of nitric oxide (NO) and K(Ca) channels to acetylcholine (ACh)-induced relaxation in isolated mesenteric arteries of spontaneously hypertensive rats (SHRs). Third branch mesenteric arteries isolated from lisinopril treated SHR rats (20 mg/kg/day for ten weeks, SHR-T) or untreated (SHR-UT) or normotensive WKY rats were mounted on tension myograph and ACh concentration-response curves were obtained. Westernblotting of eNOS and K(Ca) channels was performed. ACh-induced relaxations were similar in all groups while L-NMMA and indomethacin caused significant rightward shift only in SHR-T group. Apamin and TRAM-34 (SK(Ca) and IK(Ca) channels blockers, respectively) significantly attenuated ACh-induced maximal relaxation by similar magnitude in vessels from all three groups. In the presence of L-NMMA, indomethacin, apamin and TRAM-34 further attenuated ACh-induced relaxation only in SHR-T. Furthermore, lisinopril treatment increased expression of eNOS, SK(Ca) and BK(Ca) proteins. Lisinopril treatment increased expression of eNOS, SK(Ca), BK(Ca) channel proteins and increased the contribution of NO to ACh-mediated relaxation. This increased role of NO was apparent only when EDHF component was blocked by inhibiting SK(Ca) and IK(Ca) channels. Such may suggest that in mesenteric arteries, non-EDHF component functions act as a reserve system to provide compensatory vasodilatation if (and when) hyperpolarization that is mediated by SK(Ca) and IK(Ca) channels is reduced.

• MeSH
• antihypertenziva farmakologie   MeSH
• arteriae mesentericae účinky léků   metabolismus   patofyziologie   MeSH
• blokátory draslíkových kanálů farmakologie   MeSH
• draslíkové kanály aktivované vápníkem účinky léků   metabolismus   MeSH
• hypertenze farmakoterapie   metabolismus   patofyziologie   MeSH
• inhibitory ACE farmakologie   MeSH
• lisinopril farmakologie   MeSH
• modely nemocí na zvířatech MeSH
• nízkovodivostní draslíkové kanály aktivované vápníkem účinky léků   metabolismus   MeSH
• oxid dusnatý metabolismus   MeSH
• potkani inbrední SHR MeSH
• potkani inbrední WKY MeSH
• signální transdukce účinky léků   MeSH
• synthasa oxidu dusnatého, typ III antagonisté a inhibitory   metabolismus   MeSH
• vápníkem aktivované draslíkové kanály s vysokou vodivostí - alfa-podjednotky účinky léků   metabolismus   MeSH
• vápníkem aktivované draslíkové kanály se střední vodivostí účinky léků   metabolismus   MeSH
• vazodilatace účinky léků   MeSH
• vazodilatancia farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Considering the important roles of porphyrins in biological systems and their promising use in photodynamic therapy (PDT), the present work investigated the photophysical properties of palladium(II) 5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin (PdTSPP) and the effects of non-activated by light form of this porphyrin on contractile behaviour of isolated healthy endothelium-denuded human mesenteric arteries. METHODS: The photophysical characterisation of PdTSPP: the formation of the triplet states and the singlet oxygen were studied using laser flash photolysis. The effect of PdTSPP on the isometric contraction of artery segments from human mesentery was assessed utilising the precise method of artery isometric tension recording using Mulvany-Halpern wire myograph. RESULTS: We found that PdTSPP had a high lifetime of the triplet states τT=270μs. The calculated Stern Volmer rate constant kq=1.7×10(9)M(-1)s(-1) showed an efficient quenching by oxygen that indicated formation of singlet oxygen, O2((1)Δg). The photophysical parameters of PdTSPP, in particular its ability to generate O2((1)Δg) has defined it as an exceptionally interesting molecule for PDT. The results of the contraction study showed that PdTSPP applied in increasing concentrations (1-100μM) had no effect on the basal tone of human mesenteric artery under isometric condition. Furthermore, PdTSPP failed to potentiate or to attenuate the isometric contraction of the artery preparations precontracted with high extracellular potassium (42mM KCl) or with 1nM endothelin-1. CONCLUSIONS: The excellent photophysical properties of PdTSPP as well as the lack of an effect on the contractility of human vasculature in vitro characterise PdTSPP as a suitable compound for potential medical applications.

• MeSH
• arteriae mesentericae účinky léků   fyziologie   MeSH
• cévní rezistence účinky léků   fyziologie   MeSH
• dospělí MeSH
• fotochemoterapie metody   MeSH
• hladké svalstvo účinky léků   fyziologie   MeSH
• isometrická kontrakce účinky léků   fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• porfyriny aplikace a dávkování   MeSH
• radiosenzibilizující látky aplikace a dávkování   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• techniky in vitro MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Calcium entry through nifedipine-sensitive L-type voltage-dependent calcium channels (L-VDCC) is augmented in spontaneously hypertensive rats (SHR) characterized by enhanced sympathetic vasoconstriction. However, the changes of calcium sensitization mediated by RhoA/Rho kinase pathway are less understood. METHODS AND RESULTS: The participation of calcium entry and calcium sensitization in the control of blood pressure (BP) and vascular contraction was studied in SHR and normotensive Wistar-Kyoto (WKY) rats. The acute administration of fasudil (Rho kinase inhibitor) caused BP decrease which lasted longer in SHR. Fasudil also attenuated adrenergic contraction in femoral or mesenteric arteries of WKY and SHR. BP reduction elicited by fasudil in WKY was more pronounced than that induced by L-VDCC blocker nifedipine (-33±2 vs. -15±3% of baseline BP, P<0.001), whereas both inhibitors were similarly effective in SHR (-36±4 vs. -41±2%). Fasudil pretreatment also attenuated BP elevation elicited by L-VDCC agonist BAY K8644 more in WKY than in SHR (-63±4 vs. -42±5%, P<0.001), indicating reduced calcium sensitization in SHR. Moreover, fasudil pretreatment shifted norepinephrine dose-response curves to the right more in WKY than in SHR. The additional nifedipine pretreatment shifted these curves further to the right but this shift was more pronounced in SHR than in WKY. Thus adrenergic vasoconstriction is more dependent on L-VDCC in SHR and on RhoA/Rho kinase pathway in WKY rats. CONCLUSION: Ca sensitization mediated by RhoA/Rho kinase pathway is attenuated in SHR compared with normotensive WKY rats. This might be a part of the compensation for enhanced Ca entry through L-VDCC in genetic hypertension.

• MeSH
• 1-(5-isochinolinsulfonyl)-2-methylpiperazin analogy a deriváty   farmakologie   MeSH
• 3-pyridinkarboxylová kyselina, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)fenyl)-, methyleste farmakologie   MeSH
• adrenergní receptory metabolismus   MeSH
• agonisté vápníkových kanálů farmakologie   MeSH
• arteriae mesentericae účinky léků   MeSH
• kinázy asociované s rho antagonisté a inhibitory   metabolismus   MeSH
• krevní tlak * MeSH
• krysa rodu rattus MeSH
• nifedipin farmakologie   MeSH
• noradrenalin farmakologie   MeSH
• oxid dusnatý metabolismus   MeSH
• potkani inbrední SHR MeSH
• potkani inbrední WKY MeSH
• rhoA protein vázající GTP metabolismus   MeSH
• teplota MeSH
• vápník metabolismus   MeSH
• vápníkové kanály - typ L metabolismus   MeSH
• vazokonstrikce účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The aim of this study was to test the hypothesis that vasorelaxing action of vasonatrin peptide (VNP) is due to activation of the large-conductance Ca2+-activated potassium channel (BKCa) via guanylyl cyclase (GC)-coupled natriuretic peptide receptors (NPRs) in vascular smooth muscle cells (VSMCs). Contraction experiments were performed using human radial artery, whereas BKCa current by patch clamp was recorded in cells from rat mesenteric artery. Contractility of rings cut from human radial artery was detected in vitro. As a result, VNP induced a dose-dependent vasorelaxation of human radial artery, which could be mimicked by 8-Br-cGMP, and suppressed by TEA, a blocker of BKCa, HS-142-1, a blocker of GC-coupled NPRs, or methylene blue (MB), a selective inhibitor of guanylyl cyclase. Sequentially, whole-cell K+ currents were recorded using patch clamp techniques. BKCa current of VSMCs isolated from rat mesentery artery was obtained by subtracting the whole cell currents after applications of 10-7 mol/l iberiotoxin (IBX) from before its applications. In accordance with the results of arterial tension detection, BKCa current was significantly magnified by VNP, which could also be mimicked by 8-Br-cGMP, whereas suppressed by HS-142-1, or MB. Taken together, VNP acts as a potent vasodilator, and NPRA/B-cGMP-BKCa is one possible signaling system involved in VNP induced relaxation.

• MeSH
• arteria radialis cytologie   fyziologie   účinky léků   MeSH
• arteriae mesentericae cytologie   fyziologie   účinky léků   MeSH
• atriální natriuretický faktor farmakologie   fyziologie   MeSH
• financování organizované MeSH
• guanosinmonofosfát cyklický analogy a deriváty   farmakologie   MeSH
• guanylátcyklasa fyziologie   MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• metoda terčíkového zámku MeSH
• peptidy farmakologie   MeSH
• receptory pro atriální natriuretický faktor fyziologie   MeSH
• svaly hladké cévní cytologie   fyziologie   účinky léků   MeSH
• techniky in vitro MeSH
• tetraethylamonium farmakologie   MeSH
• vápníkem aktivované draslíkové kanály s vysokou vodivostí agonisté   fyziologie   MeSH
• vazodilatace fyziologie   účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• zvířata MeSH

Mesenteric veins are more sensitive than arteries to the constrictor effects of sympathetic nerve stimulation and alpha-adrenoceptor agonists. We tested the hypothesis that alpha(1)- and alpha(2)-adrenoceptors interact to enhance adrenergic reactivity of mesenteric veins. We studied neurogenic and agonist-induced constrictions of mesenteric veins and arteries in vitro. Norepinephrine concentration-response curves were left-shifted in veins compared to arteries. UK 14,304 (0.01-1 microM, alpha(2)-adrenoceptor receptor agonist) did not constrict arteries or veins but enhanced constrictions and Ca(2+) signals mediated by alpha(1)-adrenoceptor stimulation in veins. Yohimbine (alpha(2)-adrenoceptor receptor antagonist) and MK912 (alpha(2C)-adrenoceptor receptor antagonist), but not alpha(2A)- or alpha(2B)-adrenoceptor antagonists, produced rightward shifts in norepinephrine concentration-response curves in veins. Pharmacological studies revealed that alpha(1D)-adrenoceptors mediate venous constrictions. Norepinephrine responses in veins from alpha(2C)-adrenoceptor knock-out (KO) mice were not different from wild type veins. Yohimbine inhibited norepinephrine constrictions in alpha(2C)-adrenoceptor KO veins suggesting that there is upregulation of other alpha(2)-adrenoceptors in alpha(2C)-KO mice. These data indicate that alpha(1D)- and alpha(2C)-adrenoceptors interact in veins but not in arteries. This interaction enhances venous adrenergic reactivity. Mesenteric vein-specific alpha(2)-adrenoceptor linked Ca(2+) and perhaps other signaling pathways account for enhanced venous adrenergic reactivity.

• MeSH
• alfa-1-adrenergní receptory - agonisté farmakologie   MeSH
• alfa-1-adrenergní receptory metabolismus   fyziologie   MeSH
• alfa-2-adrenergní receptory - agonisté farmakologie   MeSH
• alfa-2-adrenergní receptory - antagonisté farmakologie   MeSH
• alfa-2-adrenergní receptory genetika   metabolismus   fyziologie   MeSH
• arteriae mesentericae účinky léků   fyziologie   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• noradrenalin fyziologie   MeSH
• protein - isoformy antagonisté a inhibitory   MeSH
• sympatický nervový systém účinky léků   MeSH
• techniky in vitro MeSH
• vápníková signalizace účinky léků   MeSH
• vazokonstrikce účinky léků   MeSH
• vena mesenterica účinky léků   fyziologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• srovnávací studie MeSH