Localization of dopamine in the endocrine hypothalamus of the rat

Summary Microspectrofluorometry, fluorescence histochemistry and light and electron microscopic autoradiography have established the presence of sub-populations of neurons in the arcuate-periventricular region of the rat hypothalamus that sequester both radiolabeled dopamine and demonstrate formaldehyde-induced fluorescence. These characteristics are consistent with a catecholaminergic function. Selective sequestration of ³H-dopamine at the light and ultrastructural level is discussed in the context of an ultrashort loop autoregulatory mechanism for this neuronal population.Supported by USPHS Program Project Grants NS-11642, RR-05403USPHS Career Development Awardee K04 GM 70001.     

Versuche zur Frage der Merkmalsübertragung beim KulturchampignonAgaricus (Psalliota)bisporus (Lge.) Sing

Ohne ZusammenfassungMit 20 Abbildungen     

Studies on the cytochrome P-450 product complexes formed during the metabolism of N,N-dimethylaniline

The oxidative metabolism of N,N-dimethylaniline by partially solubilized cytochrome P-450 from rabbit liver was found to be associated with the formation of a 424- and 448-nm product adduct of the hemoprotein. From the effects of temperature, hydrogen ion concentration, n-octylamine, extraction of the enzyme preparations with organic solvents and pretreatment of the animals with inducers of drug metabolism on both the formation of the spectral species and the enzymic C- and N-oxidation of N,N-dimethylaniline it is concluded that the 424-nm spectral change is generated from an intermediate in the C-oxidation reaction, whereas formation of the 448-nm spectral perturbation is the result of binding to cytochrome P-450 of a metabolite arising from N-oxidation of the arylamine; N-dealkylation of the parent amine is not a obligatory intermediary step in 448-nm complex formation.The 448-nm ferrohemochrome is supposed to be formed through coordination of the N-oxidized intermediate via the oxygen atom. This type of interaction appears to require considerably stronger thermal activation as compared with the 424-nm complex. The 448-nm product adduct of cytochrome P-450 is unstable in the ferric state or in the presence of sodium dithionite.     

Die züchterische Bearbeitung des Kulturchampignons (Psalliota bispora Lge.) Probleme und erste eigene Ergebnisse

Ohne ZusammenfassungMit 9 AbbildungenHerrn Prof. Dr.Hans Stubbe zum 60. Geburtstag gewidmet.