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  • 1
    Electronic Resource
    Electronic Resource
    Debromination of .alpha.,.alpha.1-dibromo ketones with a zinc-copper couple in dimethylformamide and dimethylacetamide. New reaction yielding 2-dimethylamino-4-methylene-1,3-dioxolanes (1972)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 94 (1972), S. 3201-3204 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00764a051
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Thermodynamically unstable enols. 2-Methyl-2-penten-3-ols from 4-isopropylidene-5,5-dimethyl-2-dimethylamino-1,3-dioxolane (1972)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 94 (1972), S. 7832-7837 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00777a028
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Relaxation of coronary arteries by electro-mechanical decoupling or adrenergic stimulation (1972)
    Springer
    Pflügers Archiv 337 (1972), S. 107-117 
    Details
    ISSN: 1432-2013
    Keywords: Coronary Artery ; Depolarization ; Noradrenaline ; Verapamil ; Isoproterenol ; Adrenergic Beta-Receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The contractions of isolated spiral strips from bovine and porcine coronary arteries were induced by potassium depolarization. The preparations were relaxed by verapamil and/or isoproterenol. 1. The non-activated preparation of bovine artery has a basal tone corresponding to 15±1.7% of the maximum of developed tension. 2. The contraction induced by potassium depolarization was largely prevented by 11.3 μg/ml of verapamil. In this preparation, however, 2.8 μg/ml of noradrenaline relaxed the depolarized spiral strip to the same degree as compared with values of the polarized arteries. 3. The depolarized, activated preparation is more relaxed by inhibition of calcium ion influx (verapamil) than by activation of beta-adrenergic receptors (isoproterenol). The relaxing effect takes place in the following order: noradrenaline (51.7%) 〈 isoproterenol (86.1%) 〈 verapamil (100%). 4. The polarized, non-activated preparation is more relaxed by stimulation of beta-adrenergic receptors (isoproterenol) than by inhibition of calcium ion influx (verapamil). The relaxing effect takes place in the following order: verapamil (64.4%) 〈 noradrenaline (85.3%) 〈 isoproterenol (100%). 5. The degree of maximal relaxation after verapamil, noradrenaline, or isoproterenol increases in the polarized preparation with augmented fibre stretch.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00587834
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  • 4
    Electronic Resource
    Electronic Resource
    Einfluß der Vordehnung auf die Dynamik der glatten Gefäßmuskulatur (1972)
    Springer
    Pflügers Archiv 333 (1972), S. 314-325 
    Details
    ISSN: 1432-2013
    Keywords: Vascular Smooth Muscle ; Initial Stretch ; Noradrenaline ; Angiotension ; Potassium Depolarization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Isolated helical strips of rat aorta, splenic artery (hog) and coronary artery (hog and cattle) were stretched with various intensities. Determinations of the influence of this passive stretch on the efficiency of activation by potassium-depolarization, noradrenaline or angiotensin showed an increase of the induced contraction amplitude up to an initial stretch of more than 8000 dynes per mm2 sectional area (Fig.2). 2. An augmentation of the initial stretch possibly depolarized the membrane and this caused a shift of the dose-response curve of potassium to lower concentrations (Fig.4). 3. The contraction amplitude of aorta or splenic artery induced by noradrenaline amounted to an average of 120% or of 111% of the value after potassium depolarization (Fig.1). The influence of the initial stretch on this relationship is only slight (Fig.3). The most effective concentration of noradrenaline was about 5 μg/ml; it was not possible to show a correlation between the initial stretch and the maximal effective dose of noradrenaline. 4. Noradrenaline distinctly relaxed the coronary arteries. The maximal effective dose for this reaction was also about 5 μg/ml (Fig.1). 5. Angiotensin caused a contraction in all investigated preparations (Fig.1) and became more effective after an increase of the initial stretch (Fig.3). There was no relationship between the degree of stretch and the most effective dose of angiotensin. 6. The amplitude of contraction was mainly influenced by the initial stretch and independent of the kind of activation (depolarization, noradrenaline, angiotensin). Therefore the stretch obviously affected later steps within the activation mechanism. This could be ascribed, for example, to an increase of the number of interaction sites of the contractile proteins caused by increased stretch.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00586211
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  • 5
    Electronic Resource
    Electronic Resource
    Tonusänderungen von isolierten Coronararterien durch Depolarisation und/oder Noradrenalin vor und nach Blockierung adrenerger Receptoren (1972)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 275 (1972), S. 383-392 
    Details
    ISSN: 1432-1912
    Keywords: Coronary Artery ; Noradrenaline ; Depolarization ; Adrenoceptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Isolated helical strips from coronary arteries of pigs or cattle were activated by potassium-rich solutions. The ED50 for potassium was calculated by means of an exponential function of the dose-response curve. After blockade of the alpha-adrenoceptors by 1.4 μg/ml of phenoxybenzamine the ED50 was not changed (37.4 and 37.2 mval K, respectively), but decreased to 29.4 mval K after blockade of the beta-adrenoceptors by 6.3 μg/ml of propranolol. — The maximum dilating concentration of noradrenaline for the polarized preparation was about 1 μg/ml. Noradrenaline relaxed the depolarized, contracted preparation in potassium-rich solution (135 mval K), too. Therefore, it seems that changes of the membrane potential are not required for the coronary dilatation elicited by stimulation of betaadrenoceptors. After blockade of the alpha-adrenoceptor the dilatory effect of noradrenaline was enhanced, whereas after blockade of the beta-adrenoceptors noradrenaline induced a contraction. Concerning physiological concentrations at the vascular smooth muscle of coronary arteries both adrenotropic receptors were activated by noradrenaline. The changes of contractile tension observed were discussed with respect to variations of intracellular calcium ion concentration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00501127
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    Paper (German National Licenses)
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