Responses to stimulation of the peripheral end of the right splanchnic nerve in the conscious calf

Summary The ratio at which adrenaline and noradrenaline are released from the adrenal medulla in response to stimulation of the splanchnic nerve has been established in the conscious calf. The proportion of adrenaline: noradrenaline was closely similar to that in which the 2 amines are stored in the gland and released in response to other stimuli in conscious, but not anaesthetized, calves.Acknowledgments. This work has been supported by a grant from the Agricultural Research Council, and we are also indebted to Dr D.M. Burley (Ciba) for his continued support. It is a pleasure to acknowledge the skilled technical assistance provided by Mr P.M.M. Bircham.     

Wirkungsverstärkung von Adrenalin und Noradrenalin durch Azetylcholin am isolierten Irisdilatator des Kaninchens

Summary Radial strips of the isolated iris of rabbits were suspended in streaming Tyrode's solution and their contractions were registered isometrically. The contractions produced by adrenaline or noradrenaline were increased after the administration of eserine or neostigmine. Acetylcholine in a concentration 5.10^–7–5.10^–6 M enhanced the effect of adrenaline and noradrenaline on both, the normal and the chronically denervated dilator muscle. Acetylcholine did not enhance the contractions by adrenaline and noradrenaline in the presence of atropine. Choline in a concentration of 5.10^–6 M had no effect whereas concentrations of 5.10^–5 M were slightly effective.     

Estimation of systemic catecholamine levels in the frog, using the technic of radio-enzymatic assay]

We have developed a radio-enzymatic assay for systemic catecholamines in the frog. Such are its specificity and sensibility that adrenaline and noradrenaline may be measured in 50 microliter of plasma samples, the withdrawal of which strongly influenced the results. The smaller values were obtained in plasma withdrawn from canulated animals. In this case, adrenaline was the major catecholamine in the plasma: 190 +/- 55 ng/100 ml versus 35 +/- 18 ng/100 ml for noradrenaline.     

Determination of plasma catecholamines in conscious normotensive and hypertensive (sodium and desoxycorticosterone) rats]

Plasma noradrenaline and adrenaline were measured in conscious Rats on 50 microliter samples by a radiometric technique. In normotensive Rats a moderate haemorrhage increased catecholamine levels. In Rats rendered hypertensive by salt loading and by desoxycorticosterone treatment noradrenaline levels were increased.     

Beeinflussung der «Adrenalin-Oxydasen» des Blutplasmasin vivo durch biogene Monoamine und Neuropharmaka

Summary In rats adrenaline, noradrenaline, histamine and iproniazid induced in blood plasma a significant increase of the mean of the enzyme activity of adrenaline oxidases (-globulin-factors, different from coeruloplasmin, ferritin and catalase). Reserpine showed initially an increase and later a decrease and ephedrine caused a decrease of the enzymic activity.     

Giant granules in adrenaline-secreting chromaffin cells of lizard adrenal glands after metyrapone administration

Summary Secretory granules of extraordinary size, some of them bigger than the cell nucleus, abound in the adrenaline cells of lizard adrenals after metyrapone injections during 7 days. In these granules, the bounding membrane is studded with ribosomes, and the core is formed by rounded small subunits. Some granules of this type are also found in noradrenaline cells. They may represent an exceptionally increased elaboration and storage of adrenaline, induced by metyrapone probably through its action on steroidogenic tissue.This research forms part of project No. 31.26.S1-1154 supported by the Consejo Nacional de Investigaciones Científícas y Tecnológicas.     

Tannin und Adrenalin

Summary Tannic acid in concentrations which of themselves have no action potentiates and prolongs the action of adrenaline on the isolated rabbit intestine (inhibitory effect) and on the isolated non-pregnant rabbit uterus (excitatory effect). The adrenaline-pressor effect in the decapitated cat and, in the same species, its stimulant action on the nictitating membrane (either denervated or normal) may also be potentiated by tannic acid. Since the oxidation of adrenalinein vitro is inhibited by tannic acid, it seems that this—in addition to a possible increase of permeability—is mainly responsible for the potentiation of adrenaline.     

Die Wirkung von Harmalin auf die Konzentration von Noradrenalin und Adrenalin im Herzen

Summary A single injection of harmaline increases the noradrenaline and adrenaline concentration in the rat heart. The maximum effect is obtained after about 40 min.     

Catecholamines in bovine semen

Summary In seminal plasma 5×10^–6 M noradrenaline was found to induced head-to-head association in bull spermatozoa. The sum of noradrenaline and adrenaline in freshly collected semen was 10 ng/ml (5.2×10^–8M), i.e., about 100 times lower than previously reported.     

Die Hemmbarkeit der inhibitorischen Adrenalinbzw. Noradrenalinwirkung durch Adrenolytika

Summary Dibenamine, dihydroergotamine, regitin and priscol were found to antagonize specifically the inhibitory action of adrenaline and noradrenaline on the electrically stimulated isolated ileum of the guinea-pig. The antagonistic action of dibenamine was irreversible.     

Über die Kreislaufwirkung des 1-Imidazolinylmethyl-2-β-naphthylindol (G 27032) beim gesunden Menschen

Summary In healthy human subjects, 1-imidazolinylmethyl-2-β-naphthylindole, like phentolamine, can greatly weaken or completely abolish the effect of adrenaline or noradrenaline on the circulation. In contrast to phentolamine, however, 1-imidazolinylmethyl-2-β-naphthylindole causes a decrease in heart-rate.      

Cholinesterase reactivators — Contribution to the study of their metabolic effects

Summary Cholinesterase reactivators — trimedoxim, methoxim and obidoxim — injected in the dose of 20 mg/kg s.c., increase muscle glycogen concentration in normal, but not in adrenalectomized rats. This effect may be in connection with simoultaneously found rise of serum corticosteron level. Trimedoxim decreases adrenaline, methoxim and obidoxim noradrenaline concentration in adrenals.     

Pharmacologic study of several alpha-adrenolytics

Six alpha-adrenoceptor blocking agents have been investigated in dogs and rats. 170 150 and 170 153 have been found the most potent of these agents. At low doses (0,1 microgram/kg) they reversed the pressor response to low doses of adrenaline (0,1 and 0,3 microgram/kg) and suppressed the response to high doses of adrenaline. They reduced the pressor response to noradrenaline. In addition, in dogs 170 150 increased the tachycardia caused by stimulation of the cardiac nerve. The compound prevented and reversed the inhibition caused by clonidine on the effects of cardiac nerve stimulation. 170 153 did not increase the tachycardia caused by cardiac nerve stimulation, but it prevented and reversed the inhibitory effects of clonidine on this stimulation. The results show that 170 150 and 170 153 are potent alpha-adrenoceptor blocking agents acting on both pre and post-synaptic alpha-adrenoceptors which could be interesting pharmacological tools.     

Intracerebroventricular angiotensin II increases arterial blood pressure in rhesus monkeys by stimulation of pituitary hormones and the sympathetic nervous system

Summary Intracerebroventricular injections of angiotensin II in anesthetized rhesus monkeys increase systemic blood pressure and heart rate. These effects are accompanied by an increase in plasma ADH, cortisol, adrenaline and noradrenaline. Angiotensin II may participate in central mechanisms of blood pressure regulation by its stimulatory effect on the sympathetic nervous system, on ADH and on ACTH release in primates.     

Adrenaline and the electrogenic sodium pump inRana catesbeiana sympathetic ganglion cells

Summary The effect of adrenaline on the Na⁺-pump in bullfrog (Rana catesbeiana) sympathetic ganglion cells was studied by use of electrophysiological methods. The rate of removal of excess Na⁺ injected into a ganglion cell was increased by adrenaline. The K⁺-activated hyperpolarization of cell membrane, which might be produced by an electrogenic Na⁺-pump, was also increased by adrenaline. These results suggested that adrenaline was able to accelerate the Na⁺-pump, possibly the electrogenic Na⁺-pump.     

Effect of repeated electroconvulsive shock on plasma noradrenaline and adrenaline in man

Summary The concentration of noradrenaline (NA) and of adrenaline (A) in plasma was measured before and 3, 30 and 60 min after single and repeated electroconvulsive shocks (ECS). Single ECS resulted in an activation of the sympathoadrenal medullary system; however, after the treatment had been repeated 4 times there was evidence of a diminished response of the peripheral sympathetic nervous system in comparison to the response to the first ECS.     

Vasomotor escape from adrenaline,noradrenaline or acetylcholine in the dog hind limb

Summary The noradrenaline, adrenaline and acetylcholine-induced vasoregulatory escape was demonstrated in the vascular bed of intact or skinned and denervated dog's hind limb. Escape effect disappeared or decreased markedly under elevation tissue pressure in the examined hind limb. These data indicate that tissue pressure factor may take part in the mechanism of the escape phenomenon.     

Octopamine,dopamine and noradrenaline content of the brain of the locust,Schistocerca gregaria

Summary The octopamine, dopamine and noradrenaline content of the brain of the locust,Schistocerca gregaria has been determined using sensitive radiochemical-enzymatic assays. Octopamine and dopamine are present in high concentration but the noradrenaline content is only 1/25 that of octopamine. Both reserpine and fusaric acid (a dopamine--hydroxylase inhibitor) produce a significant depletion of the octopamine stores.The author is a M.R.C. of Canada Fellow. Thanks are due to Drs.A. A. Boulton, A. V. Juorio, andP. H. Wu for helpful discussion.     

In situ noradrenaline-induced stimulation of dog thyrotrophic secretion

Summary Anterior pituitary microinfusions of noradrenaline in the dog causes a significant release of TSH while adrenaline and dopamine do not.This study was supported by Grant No. S1-049 from the Consejo Nacional de Investigaciones Cientificas y Tecnológicas, Grant No. 281 from the Consejo de Desorrallo Cientifico y Humanístico, Central University of Venezuela, and Fundación José María Vargas.     

Der Einfluss von Adrenalin auf das Verhalten des zellulären Kalziums während der K-Depolarisation des Herzmuskels von Meerschweinchen

Summary The effect of adrenaline on the cellular calcium exchange during the K-depolarization of myocardium was studied in isolated left auricles of guinea-pigs by means of the⁴⁵Ca. Increasing the extracellular K-concentration from 2.7–30 mM without corresponding reduction in sodium concentration results in a depression of contraction strength of the myocardium when current is applied. The depression is immediately reversible by using adrenaline. This was associated with a significant increase of the⁴⁵Ca exchange.