1. Forearm venous plasma noradrenaline, heart rate and intra-arterial blood pressure were measured sequentially during and after upright bicycle exercise in five normotensive and six hypertensive patients. 2. Plasma noradrenaline increased significantly between 4 and 8 min during exercise. 3. On stopping exercise blood pressure and heart rate decreased rapidly whilst plasma noradrenaline increa...

BACKGROUND The present study was designed to evaluate the preconditioning effect of different doses of noradrenaline on ischemia-induced ventricular arrhythmias in open chest anesthetized rats. METHODS The anaesthetized rats were subjected to 25 min of regional ischemia by left descending coronary artery (LAD) occlusion. In sham group, surgical procedures were done but ischemia was not applie...

The scheme of biosynthesis of noradrenaline from dopa in the mammalian tissues was presented by Blaschko (1). The conversion of dopamine to noradrenaline, mediated by dopamine-Q-hydroxylase (2), was shown to occur in the intracellular granules of the adrenal medulla (3) and heart (4, 5). The administration of tyrosine-14C (6) or dopa 14C (7 , 8) to rats results in formation of noradrenaline-14C...

AIM To investigate whether desensitization to the vasomotor effects of noradrenaline is a specific effect of electrical stimulation. METHODS Three sites on the forearm of 10 healthy volunteers were stimulated with 0.2 mA direct current for 2 min twice daily for 10 days. Noradrenaline and histamine were then displaced from ring-shaped iontophoresis chambers into two of the pretreated sites and...

The effect of enzymatically generated reduced oxygen metabolites on the activity of hepatic microsomal glutathione S-transferase activity was studied to explore possible physiological regulatory mechanisms of the enzyme. Noradrenaline and the microsomal cytochrome P-450-dependent monooxygenase system were used to generate reduced oxygen species. When noradrenaline (greater than 0.1 mM) was incu...

AIMS The aim of this study was to examine the effects of bisoprolol (BIS), a selective beta1-adrenoceptor antagonist without partial agonistic activity, on noradrenaline- and phenylephrine-evoked venoconstriction in man using the dorsal hand vein compliance technique. METHODS Twelve healthy male volunteers participated in three weekly experimental sessions. Subjects were allocated to treatmen...

Four untrained standardbred horses performed a standardized exercise test on the treadmill and an automated blood collection system programmed to obtain blood samples every 15 s was used for blood collection in order to evaluate the kinetics of adrenaline and noradrenaline. The highest average values obtained for adrenaline and noradrenaline were 15.0 +/- 3.0 and 15.8 +/- 2.8 nmol/l respectivel...

The red cell adrenoceptor affinity for the unspecific agonists adrenaline and noradrenaline and the specific beta-agonist isoprenaline was studied in vitro on whole blood of rainbow trout, Salmo gairdneri at 15 degrees C. The erythrocytic adrenoceptors could be pharmacologically characterized as beta-receptors of the 'noradrenaline'-type (beta 1-type), with an order of potency of isoprenaline g...

Chronic abdominal pain in irritable bowel syndrome (IBS) usually appears in combination with disturbed bowel habits, but the etiological relationship between these symptoms remains unclear. Noradrenaline is a major neurotransmitter controlling pain sensation in the spinal cord. To test the hypothesis that the descending noradrenergic pathway from the brain stem moderates gut motility, we examin...

Radiotracer kinetics were used to evaluate the activity of the sympathetic nervous system in 10 patients who had had unstable ischaemic symptoms within the previous 12 weeks and 10 with stable angina. Patients with recent unstable angina or angina after recent acute myocardial infarction had higher basal cardiac noradrenaline spillover than patients with stable angina. This represents a selecti...