Search results for "Papaverine"

Mechanism of the cardiovascular activity of laudanosine: comparison with papaverine and other benzylisoquinolines.

1994

1. The activity of (+/-)-laudanosine, a benzyltetrahydroisoquinoline alkaloid, was investigated in pithed rats and rat isolated aorta. Its effects on [3H]-(+)-cis-diltiazem and [3H]-nitrendipine binding to rat cerebral cortical membranes, and on the different molecular forms of cyclic nucleotide phosphodiesterases (PDE) isolated from bovine aorta were investigated. 2. The dose-response curve to methoxamine (3-300 micrograms kg-1, i.v.) in normotensive pithed rats was shifted to the right by (+/-)-laudanosine, 3 and 6 mg kg-1. 3. (+/-)-Laudanosine inhibited in a concentration-dependent manner the contractile responses evoked by noradrenaline (NA 1 microM), depolarizing solution (KCl 80 mM) o…

Nitric oxide-mediated beta 2-adrenoceptor relaxation is impaired in mesenteric veins from portal-hypertensive rats.

1996

Abstract BACKGROUND & AIMS: beta-Adrenergic relaxation seems to be mediated by nitric oxide. The aim of this study was to evaluate changes induced by portal hypertension in beta 2-adrenergic vasorelaxation. METHODS: Isolated rat mesenteric veins were relaxed by salbutamol, and nerve- mediated vasocontractions were induced by electrical field stimulation. Responses were evaluated in the presence of NG-nitro-L-arginine methyl ester (L-NAME) or tetrodotoxin. Immunocytochemical techniques were used for localization of neuronal NO synthase. RESULTS: Salbutamol-induced relaxations were decreased in rings from portal-hypertensive animals. L- NAME reduced these relaxations, but its effects were mor…

Die direkte quantitative Auswertung von Dünnschichtchromatogrammen durch Remissions- und Fluoreszenzmessungen 3. Mitt.: Bestimmung von Morphin, Codei…

1971

Es wird ein Verfahren zur quantitativen Bestimmung verschiedener Opiumalkaloide nebeneinander beschrieben, das auf der direkten Auswertung von DC durch Remissionsmessung mit Hilfe eines Chromatogramm-Spektralphotometers beruht. Anstelle des bisher ublichen Messpaltes wurde fur die Auswertung eine Kreisblende benutzt. Hierbei ist vorteilhaft, das die Form der Absorptions-Orts-Kurven keinen Einflus auf die Mesgenauigkeit besitzt, da nur die Peakhohe ausgewertet wird. Quantitative Determination of Opium Alkaloids A method for the quantitative determination of a number of single alkaloids in opium alkaloid mixtures is described, which is based on the direct evaluation of TLC by reflectance with…

Papaverine in Human Bladder Muscle

1989

It is generally assumed that drugs which induce relaxation of smooth muscles may be of clinical importance in some urological disorders; such drugs are indeed widely used, for example, in the therapy of unstable bladders or to facilitate the passage of ureteral stones. Recently, papaverine has been shown to be very effective, e.g., in relaxing smooth muscles of the corpus cavernosum penis, thereby inducing erections in many impotent men (Virag 1982). The purpose of this study is to determine the relaxing properties of papaverine in isolated muscle strips from the human detrusor and to evaluate its potential clinical importance.

�ber die Dissoziation von Funktion und Stoffwechsel des isolierten Meerschweinchenherzens unter dem Einflu� von Phosphodiesterase-Hemmstoffen

1970

The influence of several phosphodiesterase-blocking agents on some mechanical and metabolic parameters of isolated perfused guinea pig hearts was studied in order to reinvestigate the repeatedly demonstrated close correlation between these functions. 1. In concentrations which caused 50% inhibition of the phosphodiesterase, theophyllin (1.8×10−4M), ethacrynic acid (4×10−4M) and papaverine (1×10−5M) produced positive inotropic effects by increasing the rate of contraction of the heart muscle (dp/dt). The other substances tested, furosemide (5×10−4M) and hydrochlorothiazide (1.5×10−3M), did not significantly influence the mechanical function of the hearts (Fig.1, upper chart). 2. The coronary…

�ber den Einflu� von Chinin, Papaverin und Temperaturherabsetzung auf die mechanische und elektrische Aktivit�t des isolierten Uterus der Ratte

1959

Relationships between structure and vascular activity in a series of benzylisoquinolines

1997

1 1In the present work, the properties of 3-methyl isoquinoline, 3,4-dihydropapaverine, tetrahydropapaverine and tetrahydropapaveroline were compared with those of papaverine and laudanosine. The work includes functional studies on rat isolated aorta contracted with noradrenaline, caffeine or KC1, and a determination of the affinity of the compounds for α1-adrenoceptors and calcium channel binding sites, with [#H]-prazosin, [#H]-nitrendipine and [#H]-(+)-cis-diltiazem binding to rat cerebral cortical membranes. The effects of papaverine derivatives on the different molecular forms of cyclic nucleotide phosphodiesterases (PDE) isolated from bovine aorta were also determined. 2 2The three pap…

Neutrophil Adherence to Activated Saphenous Vein and Mammary Endothelium After Graft Preparation

2005

Interaction of circulating leukocytes and vascular endothelium plays an important role in vasoconstriction, endothelial dysfunction, and vascular injury. Dilation procedures of grafts before coronary artery bypass graft surgery might lead to vascular injury and subsequent bypass graft disease.We analyzed in vitro the adherence of fluorescence-labeled polymorphonuclear neutrophils (PMNs) to endothelium of human saphenous vein grafts or internal mammary artery grafts after stimulation with thrombin (0.5 to 2 U/mL) or dilating procedures. Furthermore, we investigated endothelial function of prepared grafts.Thrombin stimulation resulted in a dose-dependent increase of PMN adherence to the endot…

Effect of Intra-Arterial Infusion of Papaverine Hydrochloride on Brain Tissue Oxygen Pressure in the Management of Severe Vasospasm Following Aneurys…

2001

Despite considerable advances in diagnostic, surgical and interventional techniques, the overall outcome for patients with aneurysmal subarachnoid hemorrhage remains poor. Concerning perioperative course, cerebral ischaemia is one of the major factors causing secondary brain demage. The aim of all therapeutic interventions is the stabilization and maintance of cerebral blood flow and tissue oxygenation in order to prevent cerebral ischaemia and consecutively brain infarction [1].

Selective chiral inhibition of Ca2+ entry promoted by bisbenzyltetrahydroisoquinolines in rat uterus.

1992

Abstract The effects of diltiazem and six bisbenzyltetrahydroisoquinoline alkaloids (antioquine, 7-O-methylantioquine, dimethylantioquine, monterine, granjine and cordobimine) were studied in rat isolated uterus in order to clarify the mechanisms of their relaxant actions. All the compounds tested completely relaxed KCl-induced contractions and totally or partially inhibited oxytocin-induced rhythmic contractions. Only alkaloids with absolute configurations (1R,1′S or 1R,1′R) acted intracellularly, promoting relaxation of contractile responses induced by oxytocin in a Ca2+-free medium, as does papaverine. Alkaloids of the antioquine series (1S,1′R) selectively inhibited Ca2+ entry. The grea…