Vergleichende Untersuchungen zwischen Serum- und Gewebssaftalkohol

Zusammenfassung Bei gleichzeitiger Bestimmung des Alkoholgehaltes im Serum und in dem von der freigelegten Grundfläche einer Cantharidenblase mittels Unterdruck abgesaugten Gewebssaft (Intercellularflüssigkeit) liegen die Gewebssaftwerte stets unter den Serumspiegeln. Während die Abstände beider Kurven im ansteigenden Kurventeil infolge der unübersichtlichen Resorptionsverhältnisse meist unregelmäßig sind, laufen die Kurven im absteigenden Teil fast parallel. Der Gipfelwert wird gleichzeitig erreicht.Die geringeren Saftwerte lassen sich durch Verdampfen größerer Alkoholmengen infolge der Absaugung durch Unterdruck, womit im Prinzip eine Vakuumdestillation nachgeahmt wurde, erklären.Das wiederum läßt die Vermutung gerechtfertigt erscheinen, daß die Gewebssaftwerte in Wirklichkeit höher als festgestellt liegen und daß die resultierenden Kurven in Übereinstimmung mit den bisher bekannten experimentellen Ergebnissen zumindest in der Abbauphase nicht wesentlich von den Serumkurven abweichen, wobei es offen bleiben muß, ob eine geringe zeitliche Verspätung der Saftkurven statt hat.Trotz der methodischen Schwächen unserer Untersuchung, wird man vor allem auch im Hinblick auf das gleichzeitige Erreichen der Gipfelwerte beider Kurven den Schluß ziehen dürfen, daß sich der Diffusionsausgleich zwischen Blut und Gewebe nach abgeschlossener Resorption recht schnell vollzieht und daß demzufolge ein Blutalkoholgehalt auch für den Gewebsalkoholspiegel repräsentativ ist.Die vorliegende Mitteilung wurde auszugsweise als Vortrag auf dem Kongreß der Deutschen Gesellschaft für gerichtliche Medizin in Marburg 1956 gehalten.     

Synthesis of Noradrenaline from 3,4-Dihydroxyphenylalanine (DOPA) and Dopamine in Adrenergic Nerves of Mouse Atrium — Effect of Reserpine,Monoamine Oxidase and Tyrosine Hydroxylase Inhibition

The in vitro synthesis of noradrenaline (NA) from 3,4-dihydroxyphenylalanine (DOPA) and dopamine (DA) in the mouse atrium has been investigated, using isotope, subcellular distribution and histochemical techniques. Incubation of atrial tissue in 5 times 10^-6 M ¹⁴C-DOPA resulted in a formation of ¹⁴C-NA and ¹⁴C-DA at a rate of about 0.13 μg/g/hr, and 0.14 μg/g/hr respectively, whereas the same medium concentration of ³H-DA gave a formation of ³H-NA of about 0.25 μg/g/hr. The synthesis of NA and DA was found to be almost exclusively associated with the presence of adrenergic nerves, since it was considerably reduced after pretreatment with 6-OH-DA. Pretreatment with reserpine decreased formation of radioactive NA and DA which could be counteracted by nialamide. The effect of reserpine may be explained by inhibition of DA uptake in the amine storage granules. The antagonistic effect of nialamide is certainly due to inhibition of DA catabolism. Tyrosine hydroxylase inhibition produced by H44/68, which depleted the endogenous NA store to about 40% of normal, increased the formation of radioactive NA both from ³H-DA and ¹⁴C-DOPA. This may in part be explained by decreased competition of the endogenous precursor DA for DA-β-hydroxylase but also in part by increased storage sites available for newly formed NA.     

The formation of variants with a reversion of properties of transformed cells. VI. Stability of the reverted state

The stability of the reverted state has been analysed in revertants from polyomavirus-transformed cells in which reversion was not associated with a loss of the virus genome. The regaining of two transformed properties, the ability to form colonies at high temperature (41° C) and in soft agar, were used as markers for re-reversion. The frequency of re-reversion was studied in 12 cloned revertants after different periods of in vitro cultivation. When tested at 45 days after isolation, there were no temperature re-revertants and 2 to 184 agar re-revertants per 5 × 10⁴ cells. At 90 days after isolation, there were 14 to 784 temperature re-revertants, and 242 to 1160 agar re-revertants per 5 × 10⁴ cells. The stability of the reverted state was thus decreased by in vitro cultivation. The study of isolated re-revertants has indicated that, once a transformed property has been regained during re-reversion, the immediate progeny of the re-revertant may contain a high frequency of segregants which had lost this regained property. The re-reverted state was more stable in re-revertants from revertants that were 100 days after isolation, than in re-revertants from revertants that were 55 days after isolation. Re-reversion for one transformed property was not necessarily associated with re-reversion for the other transformed property. The different degrees of stability are explained by differences in the balance between chromosomally located factors that determine the expression and suppression of transformed properties.