Drug‐Induced Changes in Monoamine Levels in the Sympathetic Adrenergic Ganglion Cells and Terminals A histochemical study

Abstract Norberg, K.‐A.Drug‐induced changes in monoamine levels in the sympathetic adrenergic ganglion cells and terminals. A histochemical study. Acta physiol. scand. 1965.65, 221–234.— The cell bodies of peripheral adrenergic neurons in rat sympathetic ganglia have been studied and compared with the adrenergic nerve terminals in respect of drug‐induced changes in CA levels and uptake‐accumulation of CA, DOPA and 5‐HTP, using the histochemical fluorescence method of Falck and Hillarp. The cell bodies show about the same rapid depletion as the terminals following the administration of reserpine anda‐MMT but recover much more quickly. After m‐tyrosine, depletion and recovery occur rapidly and simultaneously in both parts of the neuron. The findings are in accordance with the view that the transmitter granules are formed in the cell bodies. The increased NA content observed in the superior cervical ganglion following the administration of MAO inhibitors was found to be localized predominantly to the cell bodies of the adrenergic neuron. The cells react largely as two different populations: one showing a more or less pronounced amine increase, the other no or only a slight increase. — An accumulation of CA is found in the adrenergic neuron but not in other types of peripheral neurons following the administration of DA, NA or L‐DOPA. The efficient reserpine‐insensitive mechanism for the uptake‐concentration of NA that is localized to the level of the cell membrane of the adrenergic axons and terminals (Hambergeret al. 1964, Malmfors 1965) is present also in the cell bodies. — As regards the uptake or possibly decarboxylation of DOPA and 5‐HTP, the adrenergic neuron shows a marked specificity for DOPA. — The experiments show that the cell bodies and terminals have qualitatively the same properties.