New Therapies

Paul M. Vanhoutte 한국고분자학회 2010 한국고분자학회 학술대회 연구논문 초록집 Vol.2010 No.10

Endothelium-Dependent Contractions in Hypertension : When Prostacyclin Becomes Ugly

Ovid Technologies Wolters Kluwer -American Heart A 2011 Hypertension Vol.57 No.3

Airway epithelium-derived relaxing factor: myth, reality, or naivety?

American Physiological Society 2013 American journal of physiology. Cell physiology Vol.304 No.9

<P>The presence of a healthy epithelium can moderate the contraction of the underlying airway smooth muscle. This is, in part, because epithelial cells generate inhibitory messages, whether diffusible substances, electrophysiological signals, or both. The epithelium-dependent inhibitory effect can be tonic (basal), synergistic, or evoked. Rather than a unique epithelium-derived relaxing factor (EpDRF), several known endogenous bronchoactive mediators, including nitric oxide and prostaglandin E<SUB>2</SUB>, contribute. The early concept that EpDRF diffuses all the way through the subepithelial layers to directly relax the airway smooth muscle appears unlikely. It is more plausible that the epithelial cells release true messenger molecules, which alter the production of endogenous substances (nitric oxide and/or metabolites of arachidonic acid) by the subepithelial layers. These substances then diffuse to the airway smooth muscle cells, conveying epithelium dependency.</P>

Secretoneurin facilitates endothelium-dependent relaxations in porcine coronary arteries

Chan, Calvin KY,Vanhoutte, Paul M. American Physiological Society 2011 American journal of physiology, Heart and circulat Vol.300 No.4

<P> Secretoneurin enhances the adhesion and transendothelial migration properties of monocytes and is a part of the peptide family encoded by the secretogranin II gene. The expression of the secretogranin II gene is upregulated in senescent endothelium. The present study was designed to examine the effects of secretoneurin on endothelium-dependent responsiveness. Isometric tension was measured in rings (with or without endothelium) of porcine coronary arteries. Secretoneurin did not induce contraction of quiescent or contracted rings. In preparations contracted by U-46619, relaxation was observed with high concentrations of the peptide. This relaxation was endothelium dependent and reduced by the nitric oxide synthase inhibitor N<SUP>ω</SUP>-nitro-l-arginine methyl ester (l-NAME). It was abolished when the preparations were incubated with l-NAME in combination with the cyclooxygenase inhibitor indomethacin. The relaxation was not affected by the combination of 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34) and 6,12,19,20,25,26-hexahydro-5,27:13,18:21,24-trietheno-11,7-etheno-7H-dibenzo[b,m][1,5,12,16]tetraazacyclotricosine-5,13-diiumditrifluoroacetate hydrate (UCL 1684), which abrogates endothelium-dependent hyperpolarizations. These results indicate that secretoneurin acutely induces relaxation through the activation of endothelial nitric oxide synthase (eNOS) and cyclooxygenase, with nitric oxide playing the dominant role. Prolonged (24 h) incubation with physiological concentrations of secretoneurin enhanced the relaxations to bradykinin and to the calcium ionophore A-23187, but this difference was not observed in preparations incubated with l-NAME or the calmodulin antagonist calmidazolium. Under these conditions, the relaxation to sodium nitroprusside remained unchanged. Incubation with secretoneurin significantly augmented the expression of eNOS and calmodulin as well as the dimerization of eNOS in cultures of porcine coronary arterial endothelial cells. These observations suggest that secretoneurin not only acutely causes but also, upon prolonged exposure, enhances endothelium-dependent relaxations. </P>

T-type Ca(2+) channels facilitate NO-formation, vasodilatation and NO-mediated modulation of blood pressure.

Svenningsen, Per,Andersen, Kenneth,Thuesen, Anne D,Shin, Hee-Sup,Vanhoutte, Paul M,Skøtt, Ole,Jensen, Boye L,Hill, Caryl,Hansen, Pernille B L Springer-Verlag 2014 Pfl ugers Arch Vol.466 No.12

<P>Voltage-gated calcium channels are involved in the vascular excitation-contraction mechanism and regulation of arterial blood pressure. It was hypothesized that T-type channels promote formation of nitric oxide from the endothelium. The present experiments determine the involvement of T-type channels in depolarization-dependent dilatation of mesenteric arteries and blood pressure regulation in Cav3.1 knock-out mice. Nitric oxide-dependent vasodilatation following depolarization-mediated vasoconstriction was reduced significantly in mesenteric arteries from Cav3.1(-/-) compared to wild type mice. Four days of systemic infusion of a nitric oxide (NO)-synthase-inhibitor to conscious wild type elicited a significant increase in mean arterial blood pressure that was absent in Cav3.1(-/-) mice. Immunoprecipitation and immunofluorescence labeling showed co-localization of Cav3.1 and endothelial nitric oxide synthase (eNOS) in arteries from wild type mice. Nitric oxide release measured as DAF fluorescence and cGMP levels were significantly lower in depolarized Cav3.1(-/-) compared to wild type arteries. In summary, the absence of T-type Cav3.1 channels attenuates NO-dependent dilatation in mesenteric arteries in vitro, as well as the hypertension after L-NAME infusion in vivo. Furthermore, Cav3.1 channels cluster with eNOS and promote formation of nitric oxide by the endothelium. The present findings suggest that this mechanism is important for the systemic impact of NO on peripheral resistance.</P>

Toll-Like Receptor 4 Mutation Protects Obese Mice Against Endothelial Dysfunction by Decreasing NADPH Oxidase Isoforms 1 and 4

Liang, Chao-Fan,Liu, Jacky TC,Wang, Yu,Xu, Aimin,Vanhoutte, Paul M. American Heart Association, Inc. 2013 Arteriosclerosis, thrombosis, and vascular biology Vol.33 No.4

<P><B>Objective—</B></P><P>To analyze the role of toll-like receptor 4 in modulating metabolism and endothelial function.</P><P><B>Approach and Results—</B></P><P>Type 2 diabetic mice with mutated toll-like receptor 4 (DWM) were protected from hyperglycemia and hypertension, despite an increased body weight. Isometric tension was measured in arterial rings with endothelium. Relaxations to acetylcholine were blunted in aortae and mesenteric arteries of Lepr<SUP>db/db</SUP> mice, but not in DWM mice; the endothelial NO synthase dimer/monomer ratio and endothelial NO synthase phosphorylation levels were higher in DWM preparations. These differences were abolished by apocynin. Contractions to acetylcholine (in the presence of L-NAME) were larger in carotid arteries from Lepr<SUP>db/db</SUP> mice than from DWM mice and were inhibited by indomethacin and SC560, demonstrating involvement of cyclooxygenase-1. The release of 6-ketoprostaglandin F<SUB>1α</SUB> was lower in DWM mice arteries, implying lower cyclooxygenase-1 activity. Apocynin, manganese(III) tetrakis(1-methyl-4-pyridyl) porphyrin, catalase, and diethyldithiocarbamate inhibited endothelium-dependent contractions. The mRNA and protein levels of NADPH oxidase isoforms NOX1 and NOX4 were downregulated in DWM mice arteries. The in vivo and in vitro administration of lipopolysaccharide caused endothelial dysfunction in the arteries of wild-type, but not toll-like receptor 4–mutated mice.</P><P><B>Conclusions—</B></P><P>Toll-like receptor 4 plays a key role in obesity and diabetes-associated endothelial dysfunction by increasing oxidative stress.</P>

Preparation and Characterization of Valsartan-Loaded Polyoxalate Microspheres: In vitro Release Profiles

이정근,유석철,김아람,이동원,Peter M. Kang,육순홍,Paul M. Vanhoutte,강길선 한국고분자학회 2013 Macromolecular Research Vol.21 No.5

Valsartan, a selective angiotensin II type 1 receptor (AT1R) antagonist, has a high bioavailability. Hydrophobic polyoxalate has been suggested for use in biodegradable medical devices such as absorbable sutures and controlled release applications. In this study, we developed valsartan-loaded polyoxalate microspheres by varying the polyoxalate molecular weight, surfactant content, and initial drug loading rate. The morphology of the valsartanloaded polyoxalate microspheres was evaluated by scanning electron microscopy and the hydrolysis kinetics of polyoxalate were investigated. The influences regarding the preparation parameters were evaluated with respect to the release of valsartan. The results demonstrated that the release behavior can be effectively controlled by the preparation conditions.

Double-Layered PLGA Microspheres for Effective Controlled Release of Raloxifene-HCl : Preparation and Characterization

( Jong Hak Park ),( Shin Eom ),( Dae Sung Kim ),( Won Kim ),( Yong Ki Kim ),( Young Hyun Lee ),( Hyun Hae Hong ),( Soon Hong Yuk ),( Hyung Shik Shin ),( Gil Son Khang ),( Paul M. Vanhoutte ) 한국조직공학·재생의학회 2009 조직공학과 재생의학 Vol.6 No.12

Raloxifene-HCl is a selective estrogen receptor modulator (SERM) and is currently used to prevent osteoporosis in postmenopausal women. Poly (L-lactide-co-glycolide) (PLGA) has been widely used as a carrier in controlled-release delivery systems because of good biodegradability and relatively high biocompatibility. We prepared raloxifene-HCl-loaded double-layered PLGA microspheres using an oil-in-oil-in-water double-emulsion solvent evaporation method. The raloxifene-HCl-loaded double-layered PLGA microspheres were surfacecharacterized, and there cross-sectional morphology was viewed by scanning electron microscophy (SEM). The In vitro release behavior of raloxifene-HCl over 4 weeks was analyzed by HPLC. SEM observation revealed that the double-layered PLGA microspheres had smooth surfaces and obvious differences between the core and the outer - shell. The influence of preparation parameters, such as the molecular weight of PLGA and the initial drug loading ratio, was studied with respect to release of raloxifene-HCl. The results showed that release behavior could be effectively controlled by varying the preparation parameters.