Saturation of monoamine oxidase by intraneuronal noradrenaline accumulation
| العنوان: | Saturation of monoamine oxidase by intraneuronal noradrenaline accumulation |
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| المؤلفون: | U. Trendelenburg, F. J. E. Stefano |
| المصدر: | Naunyn-Schmiedeberg's Archives of Pharmacology. 328:135-141 |
| بيانات النشر: | Springer Science and Business Media LLC, 1984. |
| سنة النشر: | 1984 |
| مصطلحات موضوعية: | Male, medicine.medical_specialty, Reserpine, Sympathetic Nervous System, Monoamine oxidase, Adrenergic, In Vitro Techniques, Axonal Transport, Methoxyhydroxyphenylglycol, Norepinephrine, Vas Deferens, Internal medicine, medicine, Animals, Monoamine Oxidase, Nerve Endings, Neurons, Pharmacology, urogenital system, Chemistry, General Medicine, Pargyline, In vitro, Rats, Kinetics, Endocrinology, Mandelic Acids, Amine gas treating, Efflux, Free nerve ending, medicine.drug |
| الوصف: | After pretreatment of the rats with reserpine and pargyline (to inhibit vesicular uptake and MAO), after an additional in vitro treatment with pargyline, and in the presence of U-0521 (to inhibit COMT), the adrenergic nerve endings of vasa deferentia were loaded with 3H-(-)-noradrenaline by exposure to various concentrations of this amine. Subsequently, tissues were washed out with amine-free solution, and the neuronal efflux of tritium was analysed. During 180 min of wash-out the apparent rate constant for the efflux of tritium decreased with increasing tritium content of the tissue. Prolongation of the wash-out period to 305 min revealed that efflux curves for tritium from heavily loaded tissues became steeper after the 180th min of wash-out. This phenomenon is indicative of saturation (followed by desaturation) of a process that limits the efflux of tritium from heavily loaded tissues. Analysis of the radioactivity of the efflux revealed a characteristic efflux curve for DOPEG: the formation of DOPEG appears to be saturated when the 3H-(-)-noradrenaline content of the tissue is high, in order to become desaturated during prolonged wash-out. These results cannot distinguish between MAO and alcohol dehydrogenase as the saturable enzyme. The formation of the mainly deaminated metabolites (during 60 min of wash-out) was determined in lightly and in heavily loaded tissues. The ratio "formation of metabolites/3H-(-)-noradrenaline content" was lower in heavily than in lightly loaded tissues; the relative decline in DOPEG formation was not accompanied by a compensatory increase in the formation of DOMA.(ABSTRACT TRUNCATED AT 250 WORDS) |
| تدمد: | 1432-1912 0028-1298 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a910e3af1c8581969d9a6c3a4d11424bTest https://doi.org/10.1007/bf00512062Test |
| حقوق: | CLOSED |
| رقم الانضمام: | edsair.doi.dedup.....a910e3af1c8581969d9a6c3a4d11424b |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14321912 00281298 |
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