U. S. von Euler

Selective Activation of Noradrenaline and Adrenaline Producing Cells in the Cat's Adrenal Gland by Hypothalamic Stimulation

By stimulating different parts of the hypothalamus in the cat, it has been possible to show that adrenal medullary secretion often contains preferentially adrenaline or noradrenaline. The results indicate that the two horomones are secreted from different cells with separate innervation.

QUANTITATION OF STRESS BY CATECHOLAMINE ANALYSIS.

The relationships between various kinds of physical and mental stress and the activity of the sympathoadrenal system, as measured by the urinary excretion of epinephrine and norepinephrine, are briefly reviewed. Gravitational stress and exposure to cold are mainly associated with an increase in the norepinephrine excretion, indicating the importance of this hormone in circulatory and temperature controlling homeostatic mechanisms. Mental stress involving exhilarating or aggressive reactions is also associated with an increase in the norepinephrine excretion. The types of emotional stress which are moinly characterized by apprehension, anxiety, pain, or general discomfort are regularly accompanied by an increase in the epinephrine excretion. The possibility of obtaining a graded response from the adrenal medulla suggests that mental stress situations may be quantitatively evaluated by urine catecholamine analysis. The importance of obtaining an objective measure of the occurrence and degree of stress in individual subjects is emphasized.

Prostaglandin-induced neurotransmission failure in the field-stimulated, isolated vas deferens

Abstract The contractile response of the guinea pig vas deferens to postganglionic nerve stimulation is inhibited by PGE 1 in low doses and potentiated by high doses. PGE 1 consistently increases the contractile response to exogenous noradrenaline, the potentiation progressively increasing with the dose of PGE 1 . Similar effects were obtained in the rabbit, cat and rat vas deferens preparation. PGE 2 was equiactive with PGE 1 , while PGF 2α was 100–1000 times less active. The effect of PGE 1 and PGE 2 on the neuroeffector system of the vas deferens preparation may be explained by a dual action, inhibition of the release of NA from the nerve terminals and potentiation of the effector response to the NA released. The inhibitory action of PGE 1 and PGE 2 , which was most marked at low impulse frequency and short pulse duration, was not blocked by polyphloretin phosphate or SC 19220, nor was it affected by addition of acetylcholine, noradrenaline, phenoxybenzamine, propranolol or tranylcypromine. The potentiation by high doses of PGE 1 of the effector response to nerve stimulation, as well as the potentiated response to exogenous noradrenaline, both effects claimed to be postjunctional, were greatly or completely antagonized by SC 19220.

Acceleration of noradrenaline biosynthesis by nerve stimulation

Abstract Prolonged preganglionic stimulation of the isolated hypogastric nerveas deferens preparation resulted in a 3-fold increase in the amount of NA synthesized from exogenous tyrosine. This increase was not the result of an increased effector organ activity since the increase was still apparent even after blockade of the effector organ response with Hydergine®. These results indicate that the isolated vas deferens preparation is capable of synthesizing NA from exogenous tyrosine and that local NA synthesis is in some way regulated by nervous activity and is not a steady state phenomenon independent of impulse traffic.

Occurrence of catecholamines in acrania and invertebrates.

THE occurrence of catecholamines in vertebrates has been extensively studied in recent years after the development of simple and accurate methods for the quantitative assay of such compounds. Relatively few investigations have been carried out with regard to their presence in invertebrates, however.

Release of noradrenaline from adrenergic transmitter granules by tyramine

Tyramin (3–50 µg/ml) setzt aus mikrogranularem Sediment von Kuhmilznerven Noradrenalin frei (Inkubation 30 min bei +20°C). Mit Dopamin und Octopamin wurde in denselben Konzentrationen keine sichere Wirkung beobachtet.

Effect of reserpine on the uptake of catecholamines in isolated nerve storage granules

Abstract The uptake of added adrenaline or noradrenaline from a suspension of partially depleted adrenergic nerve granules is not inhibited by reserpine about 10 −5 M. On the other hand pretreatment of adrenergic nerve granules with reserpine in phosphate buffer for 1 hour prevents the amine uptake. Undepleted nerve granules which normally take up added adrenaline through exchange with noradrenaline fail to do so in the presence of reserpine owing to the concomitant block of noradrenaline release.

Effect of Reserpine on Release of Noradrenaline from Transmitter Granules in Adrenergic Nerves

Direct evidence is given that reserpine, in concentrations of 0.125 to 0.625 mM, effects a release of noradrenaline from a suspension of transmitter granules isolated from bovine splenic nerves.

The Catechol Amine Content of Various Organs of the Cat After Injections and Infusions of Adrenaline and Noradrenaline

Infusions of 2.5-7.8 µg. noradrenaline/Kg./min. over 30 min. and intraperitoneal injections of noradrenaline and adrenaline up to 2000 µg/Kg, in the cat had no effect on the catechol amine content of the heart, spleen, liver, kidney and skeletal muscle, except for a slight increase in the adrenaline content. It is concluded that these organs lack the ability to accumulate circulating catechol amines administered in physiologic dosage.

Epinephrine and norepinephrine actions and use in man

Our present concepts of the role and use of epinephrine and norepinephrine in man are largely based on the doctrine of epinephrine as the emergency hormone of the adrenal medulla, originally outlined by Cannon and his associates, and the more recent finding that norepinephrine serves as neurotransmitter of the adrenergic nervous system and also as a medullary hormone. Important contributions to the knowledge of these amines have also been gained by empirical work on their use as remedies in various conditions.